Merge branch 'develop' into v2

.github/workflows/build-test.yml

@@ -32,17 +32,20 @@ jobs:
           go env
           printf "\n\nSystem Environment:\n\n"
           env
-
+          printf "Git Version: $(git version)\n\n"
           echo "::set-output name=version_tag::${GITHUB_REF/refs\/tags\//}"
           echo "::set-output name=short_sha::$(git rev-parse --short HEAD)"
           echo "::set-output name=go_cache::$(go env GOCACHE)"
+          echo "::set-output name=go_mod_cache::$(go env GOMODCACHE)"
       - name: Build Cache
         uses: actions/cache@v2
         with:
-          path: ${{ steps.env.outputs.go_cache }}
+          key: ${{ runner.os }}-go${{ matrix.go }}-${{ hashFiles('**/go.sum') }}
-          key: ${{ runner.os }}-${{ matrix.go }}-go-${{ hashFiles('**/go.sum') }}
           restore-keys: |
-            ${{ runner.os }}-${{ matrix.go }}-go
+            ${{ runner.os }}-go${{ matrix.go }}-
+          path: |
+            ${{ steps.env.outputs.go_cache }}
+            ${{ steps.env.outputs.go_mod_cache }}
       - name: Get Dependencies
         run: |
           go get -v -t -d ./...
@@ -53,14 +56,21 @@ jobs:
           CGO_ENABLED: 0
           SRC_PATH: github.com/pterodactyl/wings
         run: |
-          go build -v -trimpath -ldflags="-s -w -X ${SRC_PATH}/system.Version=dev-${GIT_COMMIT:0:7}" -o build/wings_${{ matrix.goos }}_${{ matrix.goarch }} wings.go
+          go build -v -trimpath -ldflags="-s -w -X ${SRC_PATH}/system.Version=dev-${GIT_COMMIT:0:7}" -o build/wings_${GOOS}_${GOARCH} wings.go
-          upx build/wings_${{ matrix.goos }}_${{ matrix.goarch }}
+          go build -v -trimpath -ldflags="-X ${SRC_PATH}/system.Version=dev-${GIT_COMMIT:0:7}" -o build/wings_${GOOS}_${GOARCH}_debug wings.go
-          chmod +x build/wings_${{ matrix.goos }}_${{ matrix.goarch }}
+          upx build/wings_${GOOS}_${{ matrix.goarch }}
-      - name: Test
+          chmod +x build/*
-        run: go test ./...
+      - name: Tests
-      - name: Upload Artifact
+        run: go test -race ./...
+      - name: Upload Release Artifact
         uses: actions/upload-artifact@v2
         if: ${{ github.ref == 'refs/heads/develop' || github.event_name == 'pull_request' }}
         with:
-          name: wings_${{ matrix.goos }}_${{ matrix.goarch }}
+          name: wings_linux_${{ matrix.goarch }}
-          path: build/wings_${{ matrix.goos }}_${{ matrix.goarch }}
+          path: build/wings_linux_${{ matrix.goarch }}
+      - name: Upload Debug Artifact
+        uses: actions/upload-artifact@v2
+        if: ${{ github.ref == 'refs/heads/develop' || github.event_name == 'pull_request' }}
+        with:
+          name: wings_linux_${{ matrix.goarch }}_debug
+          path: build/wings_linux_${{ matrix.goarch }}_debug

.gitignore

@@ -49,3 +49,4 @@ debug
 .DS_Store
 *.pprof
 *.pdf
+pprof.*

CHANGELOG.md

@@ -1,5 +1,52 @@
 # Changelog
 
+## v1.6.1
+### Fixed
+* Fixes error that would sometimes occur when starting a server that would cause the temporary power action lock to never be released due to a blocked channel.
+* Fixes a bug causing the CPU usage of Wings to get stuck at 100% when a server is deleted while the installation process is running.
+
+### Changed
+* Cleans up a lot of the logic for handling events between the server and environment process to make it easier to make modifications to down the road.
+* Cleans up logic handling the `StopAndWait` logic for stopping a server gracefully before terminating the process if it does not respond.
+
+## v1.6.0
+### Fixed
+* Internal logic for processing a server start event has been adjusted to attach to the Docker container before attempting to start the container. This should fix issues where a server would get stuck after pulling the container image.
+* Fixes a bug in the console output that was dropping console lines when a large number of lines were sent at once.
+
+### Changed
+* Removed the console throttle logic that would terminate a server instance that was sending too much data. This logic has been replaced with simpler logic that only throttles the console, it does not try to terminate the server. In addition, this change has reduced the number of go-routines needed by the application and dramatically simplified internal logic.
+* Removed the `--profiler` flag and replaced it with `--pprof` which will start an internal server listening on `localhost:6060` allowing you to use Go's standard `pprof` tooling.
+* Replaced the `json` log driver for Docker containers with `local` to reduce the amount of overhead when it comes to streaming logs from instances.
+
+## v1.5.6
+### Fixed
+* Rewrote handler logic for the power actions lock to hopefully address issues people have been having when a server crashes and they're unable to start it again until restarting Wings.
+* Fixes files uploaded with SFTP not being owned by the Pterodactyl user.
+* Fixes excessive memory usage when large lines are sent through the console event handler.
+
+### Changed
+* Replaced usage of `encoding/json` throughout the codebase with a more performant encoder (`goccy/go-json`) to hopefully improve overall performance for JSON operations.
+* Added custom `ContainerInspect` function to handle direct calls to Docker's CLI and make use of the new JSON encoder logic. This should reduce the total number of memory allocations and be more performant overall in a hot pathway.
+
+## v1.5.5
+### Fixed
+* Fixes sending to a closed channel when sending server logs over the websocket
+* Fixes `wings diagnostics` uploading no content
+* Fixes a panic caused by the event bus closing channels multiple times when a server is deleted
+
+## v1.5.4
+### Fixed
+* Fixes SSL paths being improperly converted to lowercase in environments where the path is case-sensitive.
+* Fixes a memory leak due to the implemention of server event processing.
+
+### Changed
+* Selecting to redact information now redacts URLs from the log output when running the diagnostic command.
+
+### Added
+* Adds support for modifying the default memory overhead percentages in environments where the shipped values are not adequate.
+* Adds support for sending the `Access-Control-Request-Private-Network` header in environments where Wings will be accessed over a private network. This is defaulted to `off`.
+
 ## v1.5.3
 ### Fixed
 * Fixes improper event registration and error handling during socket authentication that would cause the incorrect error message to be returned to the client, or no error in some scenarios. Event registration is now delayed until the socket is fully authenticated to ensure needless listeners are not registed.

Makefile

@@ -5,8 +5,8 @@ build:
 	GOOS=linux GOARCH=arm64 go build -ldflags="-s -w" -gcflags "all=-trimpath=$(pwd)" -o build/wings_linux_arm64 -v wings.go
 
 debug:
-	go build -ldflags="-X github.com/pterodactyl/wings/system.Version=$(GIT_HEAD)" -race
+	go build -ldflags="-X github.com/pterodactyl/wings/system.Version=$(GIT_HEAD)"
-	sudo ./wings --debug --ignore-certificate-errors --config config.yml
+	sudo ./wings --debug --ignore-certificate-errors --config config.yml --pprof --pprof-block-rate 1
 
 # Runs a remotly debuggable session for Wings allowing an IDE to connect and target
 # different breakpoints.

cmd/configure.go

@@ -2,7 +2,6 @@ package cmd
 
 import (
 	"crypto/tls"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -14,6 +13,7 @@ import (
 
 	"github.com/AlecAivazis/survey/v2"
 	"github.com/AlecAivazis/survey/v2/terminal"
+	"github.com/goccy/go-json"
 	"github.com/spf13/cobra"
 
 	"github.com/pterodactyl/wings/config"

cmd/diagnostics.go

@@ -2,7 +2,6 @@ package cmd
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -20,6 +19,7 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/pkg/parsers/kernel"
 	"github.com/docker/docker/pkg/parsers/operatingsystem"
+	"github.com/goccy/go-json"
 	"github.com/spf13/cobra"
 
 	"github.com/pterodactyl/wings/config"
@@ -179,6 +179,17 @@ func diagnosticsCmdRun(cmd *cobra.Command, args []string) {
 		fmt.Fprintln(output, "Logs redacted.")
 	}
 
+	if !diagnosticsArgs.IncludeEndpoints {
+		s := output.String()
+		output.Reset()
+		s = strings.ReplaceAll(s, cfg.PanelLocation, "{redacted}")
+		s = strings.ReplaceAll(s, cfg.Api.Host, "{redacted}")
+		s = strings.ReplaceAll(s, cfg.Api.Ssl.CertificateFile, "{redacted}")
+		s = strings.ReplaceAll(s, cfg.Api.Ssl.KeyFile, "{redacted}")
+		s = strings.ReplaceAll(s, cfg.System.Sftp.Address, "{redacted}")
+		output.WriteString(s)
+	}
+
 	fmt.Println("\n---------------  generated report  ---------------")
 	fmt.Println(output.String())
 	fmt.Print("---------------   end of report    ---------------\n\n")
@@ -188,16 +199,6 @@ func diagnosticsCmdRun(cmd *cobra.Command, args []string) {
 		survey.AskOne(&survey.Confirm{Message: "Upload to " + diagnosticsArgs.HastebinURL + "?", Default: false}, &upload)
 	}
 	if upload {
-		if !diagnosticsArgs.IncludeEndpoints {
-			s := output.String()
-			output.Reset()
-			a := strings.ReplaceAll(cfg.PanelLocation, s, "{redacted}")
-			a = strings.ReplaceAll(cfg.Api.Host, a, "{redacted}")
-			a = strings.ReplaceAll(cfg.Api.Ssl.CertificateFile, a, "{redacted}")
-			a = strings.ReplaceAll(cfg.Api.Ssl.KeyFile, a, "{redacted}")
-			a = strings.ReplaceAll(cfg.System.Sftp.Address, a, "{redacted}")
-			output.WriteString(a)
-		}
 		u, err := uploadToHastebin(diagnosticsArgs.HastebinURL, output.String())
 		if err == nil {
 			fmt.Println("Your report is available here: ", u)

cmd/root.go

@@ -7,10 +7,12 @@ import (
 	"fmt"
 	log2 "log"
 	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"os/signal"
 	"path"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"strings"
 	"syscall"
@@ -22,7 +24,6 @@ import (
 	"github.com/docker/docker/client"
 	"github.com/gammazero/workerpool"
 	"github.com/mitchellh/colorstring"
-	"github.com/pkg/profile"
 	"github.com/spf13/cobra"
 	"golang.org/x/crypto/acme"
 	"golang.org/x/crypto/acme/autocert"
@@ -78,7 +79,9 @@ func init() {
 	rootCommand.PersistentFlags().BoolVar(&debug, "debug", false, "pass in order to run wings in debug mode")
 
 	// Flags specifically used when running the API.
-	rootCommand.Flags().String("profiler", "", "the profiler to run for this instance")
+	rootCommand.Flags().Bool("pprof", false, "if the pprof profiler should be enabled. The profiler will bind to localhost:6060 by default")
+	rootCommand.Flags().Int("pprof-block-rate", 0, "enables block profile support, may have performance impacts")
+	rootCommand.Flags().Int("pprof-port", 6060, "If provided with --pprof, the port it will run on")
 	rootCommand.Flags().Bool("auto-tls", false, "pass in order to have wings generate and manage it's own SSL certificates using Let's Encrypt")
 	rootCommand.Flags().String("tls-hostname", "", "required with --auto-tls, the FQDN for the generated SSL certificate")
 	rootCommand.Flags().Bool("ignore-certificate-errors", false, "ignore certificate verification errors when executing API calls")
@@ -89,25 +92,6 @@ func init() {
 }
 
 func rootCmdRun(cmd *cobra.Command, _ []string) {
-	switch cmd.Flag("profiler").Value.String() {
-	case "cpu":
-		defer profile.Start(profile.CPUProfile).Stop()
-	case "mem":
-		defer profile.Start(profile.MemProfile).Stop()
-	case "alloc":
-		defer profile.Start(profile.MemProfile, profile.MemProfileAllocs).Stop()
-	case "heap":
-		defer profile.Start(profile.MemProfile, profile.MemProfileHeap).Stop()
-	case "routines":
-		defer profile.Start(profile.GoroutineProfile).Stop()
-	case "mutex":
-		defer profile.Start(profile.MutexProfile).Stop()
-	case "threads":
-		defer profile.Start(profile.ThreadcreationProfile).Stop()
-	case "block":
-		defer profile.Start(profile.BlockProfile).Stop()
-	}
-
 	printLogo()
 	log.Debug("running in debug mode")
 	log.WithField("config_file", configPath).Info("loading configuration from file")
@@ -328,6 +312,20 @@ func rootCmdRun(cmd *cobra.Command, _ []string) {
 		TLSConfig: config.DefaultTLSConfig,
 	}
 
+	profile, _ := cmd.Flags().GetBool("pprof")
+	if profile {
+		if r, _ := cmd.Flags().GetInt("pprof-block-rate"); r > 0 {
+			runtime.SetBlockProfileRate(r)
+		}
+		// Catch at least 1% of mutex contention issues.
+		runtime.SetMutexProfileFraction(100)
+
+		profilePort, _ := cmd.Flags().GetInt("pprof-port")
+		go func() {
+			http.ListenAndServe(fmt.Sprintf("localhost:%d", profilePort), nil)
+		}()
+	}
+
 	// Check if the server should run with TLS but using autocert.
 	go func(s *http.Server, api config.ApiConfiguration, sys config.SystemConfiguration, autotls bool, tlshostname string) {
 		if autotls {

config/config.go

@@ -132,6 +132,10 @@ type SystemConfiguration struct {
 	// Directory where local backups will be stored on the machine.
 	BackupDirectory string `default:"/var/lib/pterodactyl/backups" yaml:"backup_directory"`
 
+	// TmpDirectory specifies where temporary files for Pterodactyl installation processes
+	// should be created. This supports environments running docker-in-docker.
+	TmpDirectory string `default:"/tmp/pterodactyl" yaml:"tmp_directory"`
+
 	// The user that should own all of the server files, and be used for containers.
 	Username string `default:"pterodactyl" yaml:"username"`
 
@@ -222,26 +226,14 @@ type ConsoleThrottles struct {
 	// Whether or not the throttler is enabled for this instance.
 	Enabled bool `json:"enabled" yaml:"enabled" default:"true"`
 
-	// The total number of lines that can be output in a given LineResetInterval period before
+	// The total number of lines that can be output in a given Period period before
 	// a warning is triggered and counted against the server.
 	Lines uint64 `json:"lines" yaml:"lines" default:"2000"`
 
-	// The total number of throttle activations that can accumulate before a server is considered
-	// to be breaching and will be stopped. This value is decremented by one every DecayInterval.
-	MaximumTriggerCount uint64 `json:"maximum_trigger_count" yaml:"maximum_trigger_count" default:"5"`
-
 	// The amount of time after which the number of lines processed is reset to 0. This runs in
 	// a constant loop and is not affected by the current console output volumes. By default, this
 	// will reset the processed line count back to 0 every 100ms.
-	LineResetInterval uint64 `json:"line_reset_interval" yaml:"line_reset_interval" default:"100"`
+	Period uint64 `json:"line_reset_interval" yaml:"line_reset_interval" default:"100"`
-
-	// The amount of time in milliseconds that must pass without an output warning being triggered
-	// before a throttle activation is decremented.
-	DecayInterval uint64 `json:"decay_interval" yaml:"decay_interval" default:"10000"`
-
-	// The amount of time that a server is allowed to be stopping for before it is terminated
-	// forcefully if it triggers output throttles.
-	StopGracePeriod uint `json:"stop_grace_period" yaml:"stop_grace_period" default:"15"`
 }
 
 type Configuration struct {
@@ -286,6 +278,12 @@ type Configuration struct {
 	// The Panel URL is automatically allowed, this is only needed for adding
 	// additional origins.
 	AllowedOrigins []string `json:"allowed_origins" yaml:"allowed_origins"`
+
+	// AllowCORSPrivateNetwork sets the `Access-Control-Request-Private-Network` header which
+	// allows client browsers to make requests to internal IP addresses over HTTP.  This setting
+	// is only required by users running Wings without SSL certificates and using internal IP
+	// addresses in order to connect. Most users should NOT enable this setting.
+	AllowCORSPrivateNetwork bool `json:"allow_cors_private_network" yaml:"allow_cors_private_network"`
 }
 
 // NewAtPath creates a new struct and set the path where it should be stored.

config/config_docker.go

@@ -2,10 +2,10 @@ package config
 
 import (
 	"encoding/base64"
-	"encoding/json"
 	"sort"
 
 	"github.com/docker/docker/api/types"
+	"github.com/goccy/go-json"
 )
 
 type dockerNetworkInterfaces struct {
@@ -75,6 +75,8 @@ type DockerConfiguration struct {
 	// Overhead controls the memory overhead given to all containers to circumvent certain
 	// software such as the JVM not staying below the maximum memory limit.
 	Overhead Overhead `json:"overhead" yaml:"overhead"`
+
+	UsePerformantInspect bool `default:"true" json:"use_performant_inspect" yaml:"use_performant_inspect"`
 }
 
 // RegistryConfiguration defines the authentication credentials for a given

environment/docker/api.go

@@ -0,0 +1,119 @@
+package docker
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"reflect"
+	"strings"
+	"sync"
+
+	"emperror.dev/errors"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/versions"
+	"github.com/docker/docker/client"
+	"github.com/docker/docker/errdefs"
+	"github.com/goccy/go-json"
+	"github.com/pterodactyl/wings/config"
+)
+
+var (
+	o           sync.Once
+	cli         cliSettings
+	fastEnabled bool
+)
+
+type cliSettings struct {
+	enabled bool
+	proto   string
+	host    string
+	scheme  string
+	version string
+}
+
+func configure(c *client.Client) {
+	o.Do(func() {
+		fastEnabled = config.Get().Docker.UsePerformantInspect
+
+		r := reflect.ValueOf(c).Elem()
+		cli.proto = r.FieldByName("proto").String()
+		cli.host = r.FieldByName("addr").String()
+		cli.scheme = r.FieldByName("scheme").String()
+		cli.version = r.FieldByName("version").String()
+	})
+}
+
+// ContainerInspect is a rough equivalent of Docker's client.ContainerInspect()
+// but re-written to use a more performant JSON decoder. This is important since
+// a large number of requests to this endpoint are spawned by Wings, and the
+// standard "encoding/json" shows its performance woes badly even with single
+// containers running.
+func (e *Environment) ContainerInspect(ctx context.Context) (types.ContainerJSON, error) {
+	configure(e.client)
+
+	// Support feature flagging of this functionality so that if something goes
+	// wrong for now it is easy enough for people to switch back to the older method
+	// of fetching stats.
+	if !fastEnabled {
+		return e.client.ContainerInspect(ctx, e.Id)
+	}
+
+	var st types.ContainerJSON
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, "/containers/"+e.Id+"/json", nil)
+	if err != nil {
+		return st, errors.WithStack(err)
+	}
+
+	if cli.proto == "unix" || cli.proto == "npipe" {
+		req.Host = "docker"
+	}
+
+	req.URL.Host = cli.host
+	req.URL.Scheme = cli.scheme
+
+	res, err := e.client.HTTPClient().Do(req)
+	if err != nil {
+		if res == nil {
+			return st, errdefs.Unknown(err)
+		}
+		return st, errdefs.FromStatusCode(err, res.StatusCode)
+	}
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return st, errors.Wrap(err, "failed to read response body from Docker")
+	}
+	if err := parseErrorFromResponse(res, body); err != nil {
+		return st, errdefs.FromStatusCode(err, res.StatusCode)
+	}
+	if err := json.Unmarshal(body, &st); err != nil {
+		return st, errors.WithStack(err)
+	}
+	return st, nil
+}
+
+// parseErrorFromResponse is a re-implementation of Docker's
+// client.checkResponseErr() function.
+func parseErrorFromResponse(res *http.Response, body []byte) error {
+	if res.StatusCode >= 200 && res.StatusCode < 400 {
+		return nil
+	}
+
+	var ct string
+	if res.Header != nil {
+		ct = res.Header.Get("Content-Type")
+	}
+
+	var emsg string
+	if (cli.version == "" || versions.GreaterThan(cli.version, "1.23")) && ct == "application/json" {
+		var errResp types.ErrorResponse
+		if err := json.Unmarshal(body, &errResp); err != nil {
+			return errors.WithStack(err)
+		}
+		emsg = strings.TrimSpace(errResp.Message)
+	} else {
+		emsg = strings.TrimSpace(string(body))
+	}
+
+	return errors.Wrap(errors.New(emsg), "Error response from daemon")
+}

environment/docker/container.go

@@ -3,7 +3,6 @@ package docker
 import (
 	"bufio"
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"strconv"
@@ -12,11 +11,12 @@ import (
 
 	"emperror.dev/errors"
 	"github.com/apex/log"
+	"github.com/buger/jsonparser"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/client"
-	"github.com/docker/docker/daemon/logger/jsonfilelog"
+	"github.com/docker/docker/daemon/logger/local"
 
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
@@ -38,13 +38,13 @@ func (nw noopWriter) Write(b []byte) (int, error) {
 }
 
 // Attach attaches to the docker container itself and ensures that we can pipe
-// data in and out of the process stream. This should not be used for reading
+// data in and out of the process stream. This should always be called before
-// console data as you *will* miss important output at the beginning because of
+// you have started the container, but after you've ensured it exists.
-// the time delay with attaching to the output.
 //
 // Calling this function will poll resources for the container in the background
-// until the provided context is canceled by the caller. Failure to cancel said
+// until the container is stopped. The context provided to this function is used
-// context will cause background memory leaks as the goroutine will not exit.
+// for the purposes of attaching to the container, a seecond context is created
+// within the function for managing polling.
 func (e *Environment) Attach(ctx context.Context) error {
 	if e.IsAttached() {
 		return nil
@@ -118,7 +118,7 @@ func (e *Environment) InSituUpdate() error {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
 	defer cancel()
 
-	if _, err := e.client.ContainerInspect(ctx, e.Id); err != nil {
+	if _, err := e.ContainerInspect(ctx); err != nil {
 		// If the container doesn't exist for some reason there really isn't anything
 		// we can do to fix that in this process (it doesn't make sense at least). In those
 		// cases just return without doing anything since we still want to save the configuration
@@ -150,7 +150,7 @@ func (e *Environment) Create() error {
 	// If the container already exists don't hit the user with an error, just return
 	// the current information about it which is what we would do when creating the
 	// container anyways.
-	if _, err := e.client.ContainerInspect(context.Background(), e.Id); err == nil {
+	if _, err := e.ContainerInspect(context.Background()); err == nil {
 		return nil
 	} else if !client.IsErrNotFound(err) {
 		return errors.Wrap(err, "environment/docker: failed to inspect container")
@@ -175,7 +175,7 @@ func (e *Environment) Create() error {
 	conf := &container.Config{
 		Hostname:     e.Id,
 		Domainname:   config.Get().Docker.Domainname,
-		User:         strconv.Itoa(config.Get().System.User.Uid),
+		User:         strconv.Itoa(config.Get().System.User.Uid) + ":" + strconv.Itoa(config.Get().System.User.Gid),
 		AttachStdin:  true,
 		AttachStdout: true,
 		AttachStderr: true,
@@ -216,11 +216,12 @@ func (e *Environment) Create() error {
 		// since we only need it for the last few hundred lines of output and don't care
 		// about anything else in it.
 		LogConfig: container.LogConfig{
-			Type: jsonfilelog.Name,
+			Type: local.Name,
 			Config: map[string]string{
 				"max-size": "5m",
 				"max-file": "1",
 				"compress": "false",
+				"mode":     "non-blocking",
 			},
 		},
 
@@ -364,11 +365,6 @@ func (e *Environment) scanOutput(reader io.ReadCloser) {
 	go e.followOutput()
 }
 
-type imagePullStatus struct {
-	Status   string `json:"status"`
-	Progress string `json:"progress"`
-}
-
 // Pulls the image from Docker. If there is an error while pulling the image
 // from the source but the image already exists locally, we will report that
 // error to the logger but continue with the process.
@@ -454,12 +450,11 @@ func (e *Environment) ensureImageExists(image string) error {
 	scanner := bufio.NewScanner(out)
 
 	for scanner.Scan() {
-		s := imagePullStatus{}
+		b := scanner.Bytes()
-		fmt.Println(scanner.Text())
+		status, _ := jsonparser.GetString(b, "status")
+		progress, _ := jsonparser.GetString(b, "progress")
 
-		if err := json.Unmarshal(scanner.Bytes(), &s); err == nil {
+		e.Events().Publish(environment.DockerImagePullStatus, status+" "+progress)
-			e.Events().Publish(environment.DockerImagePullStatus, s.Status+" "+s.Progress)
-		}
 	}
 
 	if err := scanner.Err(); err != nil {

environment/docker/environment.go

@@ -10,7 +10,6 @@ import (
 	"github.com/apex/log"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
-
 	"github.com/pterodactyl/wings/environment"
 	"github.com/pterodactyl/wings/events"
 	"github.com/pterodactyl/wings/remote"
@@ -28,7 +27,6 @@ var _ environment.ProcessEnvironment = (*Environment)(nil)
 
 type Environment struct {
 	mu      sync.RWMutex
-	eventMu sync.Once
 
 	// The public identifier for this environment. In this case it is the Docker container
 	// name that will be used for all instances created under it.
@@ -74,6 +72,7 @@ func New(id string, m *Metadata, c *environment.Configuration) (*Environment, er
 		meta:          m,
 		client:        cli,
 		st:            system.NewAtomicString(environment.ProcessOfflineState),
+		emitter:       events.NewBus(),
 	}
 
 	return e, nil
@@ -87,46 +86,43 @@ func (e *Environment) Type() string {
 	return "docker"
 }
 
-// Set if this process is currently attached to the process.
+// SetStream sets the current stream value from the Docker client. If a nil
+// value is provided we assume that the stream is no longer operational and the
+// instance is effectively offline.
 func (e *Environment) SetStream(s *types.HijackedResponse) {
 	e.mu.Lock()
-	defer e.mu.Unlock()
-
 	e.stream = s
+	e.mu.Unlock()
 }
 
-// Determine if the this process is currently attached to the container.
+// IsAttached determine if the this process is currently attached to the
+// container instance by checking if the stream is nil or not.
 func (e *Environment) IsAttached() bool {
 	e.mu.RLock()
 	defer e.mu.RUnlock()
-
 	return e.stream != nil
 }
 
+// Events returns an event bus for the environment.
 func (e *Environment) Events() *events.Bus {
-	e.eventMu.Do(func() {
-		e.emitter = events.NewBus()
-	})
-
 	return e.emitter
 }
 
-// Determines if the container exists in this environment. The ID passed through should be the
+// Exists determines if the container exists in this environment. The ID passed
-// server UUID since containers are created utilizing the server UUID as the name and docker
+// through should be the server UUID since containers are created utilizing the
-// will work fine when using the container name as the lookup parameter in addition to the longer
+// server UUID as the name and docker will work fine when using the container
-// ID auto-assigned when the container is created.
+// name as the lookup parameter in addition to the longer ID auto-assigned when
+// the container is created.
 func (e *Environment) Exists() (bool, error) {
-	_, err := e.client.ContainerInspect(context.Background(), e.Id)
+	_, err := e.ContainerInspect(context.Background())
 	if err != nil {
 		// If this error is because the container instance wasn't found via Docker we
 		// can safely ignore the error and just return false.
 		if client.IsErrNotFound(err) {
 			return false, nil
 		}
-
 		return false, err
 	}
-
 	return true, nil
 }
 
@@ -140,17 +136,17 @@ func (e *Environment) Exists() (bool, error) {
 //
 // @see docker/client/errors.go
 func (e *Environment) IsRunning(ctx context.Context) (bool, error) {
-	c, err := e.client.ContainerInspect(ctx, e.Id)
+	c, err := e.ContainerInspect(ctx)
 	if err != nil {
 		return false, err
 	}
 	return c.State.Running, nil
 }
 
-// Determine the container exit state and return the exit code and whether or not
+// ExitState returns the container exit state, the exit code and whether or not
 // the container was killed by the OOM killer.
 func (e *Environment) ExitState() (uint32, bool, error) {
-	c, err := e.client.ContainerInspect(context.Background(), e.Id)
+	c, err := e.ContainerInspect(context.Background())
 	if err != nil {
 		// I'm not entirely sure how this can happen to be honest. I tried deleting a
 		// container _while_ a server was running and wings gracefully saw the crash and
@@ -164,15 +160,13 @@ func (e *Environment) ExitState() (uint32, bool, error) {
 		if client.IsErrNotFound(err) {
 			return 1, false, nil
 		}
-
 		return 0, false, err
 	}
-
 	return uint32(c.State.ExitCode), c.State.OOMKilled, nil
 }
 
-// Returns the environment configuration allowing a process to make modifications of the
+// Config returns the environment configuration allowing a process to make
-// environment on the fly.
+// modifications of the environment on the fly.
 func (e *Environment) Config() *environment.Configuration {
 	e.mu.RLock()
 	defer e.mu.RUnlock()
@@ -180,12 +174,11 @@ func (e *Environment) Config() *environment.Configuration {
 	return e.Configuration
 }
 
-// Sets the stop configuration for the environment.
+// SetStopConfiguration sets the stop configuration for the environment.
 func (e *Environment) SetStopConfiguration(c remote.ProcessStopConfiguration) {
 	e.mu.Lock()
-	defer e.mu.Unlock()
-
 	e.meta.Stop = c
+	e.mu.Unlock()
 }
 
 func (e *Environment) SetImage(i string) {

environment/docker/power.go

@@ -66,7 +66,7 @@ func (e *Environment) Start(ctx context.Context) error {
 		}
 	}()
 
-	if c, err := e.client.ContainerInspect(ctx, e.Id); err != nil {
+	if c, err := e.ContainerInspect(ctx); err != nil {
 		// Do nothing if the container is not found, we just don't want to continue
 		// to the next block of code here. This check was inlined here to guard against
 		// a nil-pointer when checking c.State below.
@@ -111,14 +111,24 @@ func (e *Environment) Start(ctx context.Context) error {
 	actx, cancel := context.WithTimeout(ctx, time.Second*30)
 	defer cancel()
 
+	// You must attach to the instance _before_ you start the container. If you do this
+	// in the opposite order you'll enter a deadlock condition where we're attached to
+	// the instance successfully, but the container has already stopped and you'll get
+	// the entire program into a very confusing state.
+	//
+	// By explicitly attaching to the instance before we start it, we can immediately
+	// react to errors/output stopping/etc. when starting.
+	if err := e.Attach(actx); err != nil {
+		return err
+	}
+
 	if err := e.client.ContainerStart(actx, e.Id, types.ContainerStartOptions{}); err != nil {
 		return errors.WrapIf(err, "environment/docker: failed to start container")
 	}
 
 	// No errors, good to continue through.
 	sawError = false
-
+	return nil
-	return e.Attach(actx)
 }
 
 // Stop stops the container that the server is running in. This will allow up to
@@ -128,9 +138,7 @@ func (e *Environment) Start(ctx context.Context) error {
 // You most likely want to be using WaitForStop() rather than this function,
 // since this will return as soon as the command is sent, rather than waiting
 // for the process to be completed stopped.
-//
+func (e *Environment) Stop(ctx context.Context) error {
-// TODO: pass context through from the server instance.
-func (e *Environment) Stop() error {
 	e.mu.RLock()
 	s := e.meta.Stop
 	e.mu.RUnlock()
@@ -154,7 +162,7 @@ func (e *Environment) Stop() error {
 		case "SIGTERM":
 			signal = syscall.SIGTERM
 		}
-		return e.Terminate(signal)
+		return e.Terminate(ctx, signal)
 	}
 
 	// If the process is already offline don't switch it back to stopping. Just leave it how
@@ -169,8 +177,10 @@ func (e *Environment) Stop() error {
 		return e.SendCommand(s.Value)
 	}
 
-	t := time.Second * 30
+	// Allow the stop action to run for however long it takes, similar to executing a command
-	if err := e.client.ContainerStop(context.Background(), e.Id, &t); err != nil {
+	// and using a different logic pathway to wait for the container to stop successfully.
+	t := time.Duration(-1)
+	if err := e.client.ContainerStop(ctx, e.Id, &t); err != nil {
 		// If the container does not exist just mark the process as stopped and return without
 		// an error.
 		if client.IsErrNotFound(err) {
@@ -188,45 +198,66 @@ func (e *Environment) Stop() error {
 // command. If the server does not stop after seconds have passed, an error will
 // be returned, or the instance will be terminated forcefully depending on the
 // value of the second argument.
-func (e *Environment) WaitForStop(seconds uint, terminate bool) error {
+//
-	if err := e.Stop(); err != nil {
+// Calls to Environment.Terminate() in this function use the context passed
-		return err
+// through since we don't want to prevent termination of the server instance
+// just because the context.WithTimeout() has expired.
+func (e *Environment) WaitForStop(ctx context.Context, duration time.Duration, terminate bool) error {
+	tctx, cancel := context.WithTimeout(context.Background(), duration)
+	defer cancel()
+
+	// If the parent context is canceled, abort the timed context for termination.
+	go func() {
+		select {
+		case <-ctx.Done():
+			cancel()
+		case <-tctx.Done():
+			// When the timed context is canceled, terminate this routine since we no longer
+			// need to worry about the parent routine being canceled.
+			break
+		}
+	}()
+
+	doTermination := func (s string) error {
+		e.log().WithField("step", s).WithField("duration", duration).Warn("container stop did not complete in time, terminating process...")
+		return e.Terminate(ctx, os.Kill)
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(seconds)*time.Second)
+	// We pass through the timed context for this stop action so that if one of the
-	defer cancel()
+	// internal docker calls fails to ever finish before we've exhausted the time limit
+	// the resources get cleaned up, and the exection is stopped.
+	if err := e.Stop(tctx); err != nil {
+		if terminate && errors.Is(err, context.DeadlineExceeded) {
+			return doTermination("stop")
+		}
+		return err
+	}
 
 	// Block the return of this function until the container as been marked as no
 	// longer running. If this wait does not end by the time seconds have passed,
 	// attempt to terminate the container, or return an error.
-	ok, errChan := e.client.ContainerWait(ctx, e.Id, container.WaitConditionNotRunning)
+	ok, errChan := e.client.ContainerWait(tctx, e.Id, container.WaitConditionNotRunning)
 	select {
 	case <-ctx.Done():
-		if ctxErr := ctx.Err(); ctxErr != nil {
+		if err := ctx.Err(); err != nil {
 			if terminate {
-				log.WithField("container_id", e.Id).Info("server did not stop in time, executing process termination")
+				return doTermination("parent-context")
-
-				return e.Terminate(os.Kill)
 			}
-
+			return err
-			return ctxErr
 		}
 	case err := <-errChan:
 		// If the error stems from the container not existing there is no point in wasting
 		// CPU time to then try and terminate it.
-		if err != nil && !client.IsErrNotFound(err) {
+		if err == nil || client.IsErrNotFound(err) {
-			if terminate {
+			return nil
-				l := log.WithField("container_id", e.Id)
-				if errors.Is(err, context.DeadlineExceeded) {
-					l.Warn("deadline exceeded for container stop; terminating process")
-				} else {
-					l.WithField("error", err).Warn("error while waiting for container stop; terminating process")
-				}
-
-				return e.Terminate(os.Kill)
-			}
-			return errors.WrapIf(err, "environment/docker: error waiting on container to enter \"not-running\" state")
 		}
+		if terminate {
+			if !errors.Is(err, context.DeadlineExceeded) {
+				e.log().WithField("error", err).Warn("error while waiting for container stop; terminating process")
+			}
+			return doTermination("wait")
+		}
+		return errors.WrapIf(err, "environment/docker: error waiting on container to enter \"not-running\" state")
 	case <-ok:
 	}
 
@@ -234,8 +265,8 @@ func (e *Environment) WaitForStop(seconds uint, terminate bool) error {
 }
 
 // Terminate forcefully terminates the container using the signal provided.
-func (e *Environment) Terminate(signal os.Signal) error {
+func (e *Environment) Terminate(ctx context.Context, signal os.Signal) error {
-	c, err := e.client.ContainerInspect(context.Background(), e.Id)
+	c, err := e.ContainerInspect(ctx)
 	if err != nil {
 		// Treat missing containers as an okay error state, means it is obviously
 		// already terminated at this point.
@@ -260,7 +291,7 @@ func (e *Environment) Terminate(signal os.Signal) error {
 	// We set it to stopping than offline to prevent crash detection from being triggered.
 	e.SetState(environment.ProcessStoppingState)
 	sig := strings.TrimSuffix(strings.TrimPrefix(signal.String(), "signal "), "ed")
-	if err := e.client.ContainerKill(context.Background(), e.Id, sig); err != nil && !client.IsErrNotFound(err) {
+	if err := e.client.ContainerKill(ctx, e.Id, sig); err != nil && !client.IsErrNotFound(err) {
 		return errors.WithStack(err)
 	}
 	e.SetState(environment.ProcessOfflineState)

environment/docker/stats.go

@@ -2,13 +2,13 @@ package docker
 
 import (
 	"context"
-	"encoding/json"
 	"io"
 	"math"
 	"time"
 
 	"emperror.dev/errors"
 	"github.com/docker/docker/api/types"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/environment"
 )
@@ -16,7 +16,7 @@ import (
 // Uptime returns the current uptime of the container in milliseconds. If the
 // container is not currently running this will return 0.
 func (e *Environment) Uptime(ctx context.Context) (int64, error) {
-	ins, err := e.client.ContainerInspect(ctx, e.Id)
+	ins, err := e.ContainerInspect(ctx)
 	if err != nil {
 		return 0, errors.Wrap(err, "environment: could not inspect container")
 	}

environment/environment.go

@@ -3,6 +3,7 @@ package environment
 import (
 	"context"
 	"os"
+	"time"
 
 	"github.com/pterodactyl/wings/events"
 )
@@ -58,18 +59,20 @@ type ProcessEnvironment interface {
 	// can be started an error should be returned.
 	Start(ctx context.Context) error
 
-	// Stops a server instance. If the server is already stopped an error should
+	// Stop stops a server instance. If the server is already stopped an error will
-	// not be returned.
+	// not be returned, this function will act as a no-op.
-	Stop() error
+	Stop(ctx context.Context) error
 
-	// Waits for a server instance to stop gracefully. If the server is still detected
+	// WaitForStop waits for a server instance to stop gracefully. If the server is
-	// as running after seconds, an error will be returned, or the server will be terminated
+	// still detected as running after "duration", an error will be returned, or the server
-	// depending on the value of the second argument.
+	// will be terminated depending on the value of the second argument. If the context
-	WaitForStop(seconds uint, terminate bool) error
+	// provided is canceled the underlying wait conditions will be stopped and the
+	// entire loop will be ended (potentially without stopping or terminating).
+	WaitForStop(ctx context.Context, duration time.Duration, terminate bool) error
 
-	// Terminates a running server instance using the provided signal. If the server
+	// Terminate stops a running server instance using the provided signal. This function
-	// is not running no error should be returned.
+	// is a no-op if the server is already stopped.
-	Terminate(signal os.Signal) error
+	Terminate(ctx context.Context, signal os.Signal) error
 
 	// Destroys the environment removing any containers that were created (in Docker
 	// environments at least).

events/events.go

@@ -2,10 +2,11 @@ package events
 
 import (
 	"strings"
-	"sync"
-)
 
-type Listener chan Event
+	"emperror.dev/errors"
+	"github.com/goccy/go-json"
+	"github.com/pterodactyl/wings/system"
+)
 
 // Event represents an Event sent over a Bus.
 type Event struct {
@@ -15,112 +16,55 @@ type Event struct {
 
 // Bus represents an Event Bus.
 type Bus struct {
-	listenersMx sync.Mutex
+	*system.SinkPool
-	listeners   map[string][]Listener
 }
 
-// NewBus returns a new empty Event Bus.
+// NewBus returns a new empty Bus. This is simply a nicer wrapper around the
+// system.SinkPool implementation that allows for more simplistic usage within
+// the codebase.
+//
+// All of the events emitted out of this bus are byte slices that can be decoded
+// back into an events.Event interface.
 func NewBus() *Bus {
 	return &Bus{
-		listeners: make(map[string][]Listener),
+		system.NewSinkPool(),
-	}
-}
-
-// Off unregisters a listener from the specified topics on the Bus.
-func (b *Bus) Off(listener Listener, topics ...string) {
-	b.listenersMx.Lock()
-	defer b.listenersMx.Unlock()
-
-	for _, topic := range topics {
-		b.off(topic, listener)
-	}
-}
-
-func (b *Bus) off(topic string, listener Listener) bool {
-	listeners, ok := b.listeners[topic]
-	if !ok {
-		return false
-	}
-	for i, l := range listeners {
-		if l != listener {
-			continue
-		}
-
-		listeners = append(listeners[:i], listeners[i+1:]...)
-		b.listeners[topic] = listeners
-		return true
-	}
-	return false
-}
-
-// On registers a listener to the specified topics on the Bus.
-func (b *Bus) On(listener Listener, topics ...string) {
-	b.listenersMx.Lock()
-	defer b.listenersMx.Unlock()
-
-	for _, topic := range topics {
-		b.on(topic, listener)
-	}
-}
-
-func (b *Bus) on(topic string, listener Listener) {
-	listeners, ok := b.listeners[topic]
-	if !ok {
-		b.listeners[topic] = []Listener{listener}
-	} else {
-		b.listeners[topic] = append(listeners, listener)
 	}
 }
 
 // Publish publishes a message to the Bus.
 func (b *Bus) Publish(topic string, data interface{}) {
-	// Some of our topics for the socket support passing a more specific namespace,
+	// Some of our actions for the socket support passing a more specific namespace,
 	// such as "backup completed:1234" to indicate which specific backup was completed.
 	//
 	// In these cases, we still need to send the event using the standard listener
 	// name of "backup completed".
 	if strings.Contains(topic, ":") {
 		parts := strings.SplitN(topic, ":", 2)
-
 		if len(parts) == 2 {
 			topic = parts[0]
 		}
 	}
 
-	b.listenersMx.Lock()
+	enc, err := json.Marshal(Event{Topic: topic, Data: data})
-	defer b.listenersMx.Unlock()
+	if err != nil {
-
+		panic(errors.WithStack(err))
-	listeners, ok := b.listeners[topic]
-	if !ok {
-		return
 	}
-	if len(listeners) < 1 {
+	b.Push(enc)
-		return
-	}
-
-	var wg sync.WaitGroup
-	event := Event{Topic: topic, Data: data}
-	for _, listener := range listeners {
-		l := listener
-		wg.Add(1)
-		go func(l Listener, event Event) {
-			defer wg.Done()
-			l <- event
-		}(l, event)
-	}
-	wg.Wait()
 }
 
-// Destroy destroys the Event Bus by unregistering and closing all listeners.
+// MustDecode decodes the event byte slice back into an events.Event struct or
-func (b *Bus) Destroy() {
+// panics if an error is encountered during this process.
-	b.listenersMx.Lock()
+func MustDecode(data []byte) (e Event) {
-	defer b.listenersMx.Unlock()
+	if err := DecodeTo(data, &e); err != nil {
-
+		panic(err)
-	for _, listeners := range b.listeners {
-		for _, listener := range listeners {
-			close(listener)
-		}
 	}
-
+	return
-	b.listeners = make(map[string][]Listener)
+}
+
+// DecodeTo decodes a byte slice of event data into the given interface.
+func DecodeTo(data []byte, v interface{}) error {
+	if err := json.Unmarshal(data, &v); err != nil {
+		return errors.Wrap(err, "events: failed to decode byte slice")
+	}
+	return nil
 }

events/events_test.go

@@ -9,172 +9,90 @@ import (
 
 func TestNewBus(t *testing.T) {
 	g := Goblin(t)
-	bus := NewBus()
 
-	g.Describe("NewBus", func() {
+	g.Describe("Events", func() {
-		g.It("is not nil", func() {
+		var bus *Bus
-			g.Assert(bus).IsNotNil("Bus expected to not be nil")
+		g.BeforeEach(func() {
-			g.Assert(bus.listeners).IsNotNil("Bus#listeners expected to not be nil")
+			bus = NewBus()
-		})
-	})
-}
-
-func TestBus_Off(t *testing.T) {
-	g := Goblin(t)
-
-	const topic = "test"
-
-	g.Describe("Off", func() {
-		g.It("unregisters listener", func() {
-			bus := NewBus()
-
-			g.Assert(bus.listeners[topic]).IsNotNil()
-			g.Assert(len(bus.listeners[topic])).IsZero()
-			listener := make(chan Event)
-			bus.On(listener, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(1, "Listener was not registered")
-
-			bus.Off(listener, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(0, "Topic still has one or more listeners")
-
-			close(listener)
 		})
 
-		g.It("unregisters correct listener", func() {
+		g.Describe("NewBus", func() {
-			bus := NewBus()
+			g.It("is not nil", func() {
-
+				g.Assert(bus).IsNotNil("Bus expected to not be nil")
-			listener := make(chan Event)
+			})
-			listener2 := make(chan Event)
-			listener3 := make(chan Event)
-			bus.On(listener, topic)
-			bus.On(listener2, topic)
-			bus.On(listener3, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(3, "Listeners were not registered")
-
-			bus.Off(listener, topic)
-			bus.Off(listener3, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(1, "Expected 1 listener to remain")
-
-			if bus.listeners[topic][0] != listener2 {
-				// A normal Assert does not properly compare channels.
-				g.Fail("wrong listener unregistered")
-			}
-
-			// Cleanup
-			bus.Off(listener2, topic)
-			close(listener)
-			close(listener2)
-			close(listener3)
-		})
-	})
-}
-
-func TestBus_On(t *testing.T) {
-	g := Goblin(t)
-
-	const topic = "test"
-
-	g.Describe("On", func() {
-		g.It("registers listener", func() {
-			bus := NewBus()
-
-			g.Assert(bus.listeners[topic]).IsNotNil()
-			g.Assert(len(bus.listeners[topic])).IsZero()
-			listener := make(chan Event)
-			bus.On(listener, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(1, "Listener was not registered")
-
-			if bus.listeners[topic][0] != listener {
-				// A normal Assert does not properly compare channels.
-				g.Fail("wrong listener registered")
-			}
-
-			// Cleanup
-			bus.Off(listener, topic)
-			close(listener)
-		})
-	})
-}
-
-func TestBus_Publish(t *testing.T) {
-	g := Goblin(t)
-
-	const topic = "test"
-	const message = "this is a test message!"
-
-	g.Describe("Publish", func() {
-		g.It("publishes message", func() {
-			bus := NewBus()
-
-			g.Assert(bus.listeners[topic]).IsNotNil()
-			g.Assert(len(bus.listeners[topic])).IsZero()
-			listener := make(chan Event)
-			bus.On(listener, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(1, "Listener was not registered")
-
-			done := make(chan struct{}, 1)
-			go func() {
-				select {
-				case m := <-listener:
-					g.Assert(m.Topic).Equal(topic)
-					g.Assert(m.Data).Equal(message)
-				case <-time.After(1 * time.Second):
-					g.Fail("listener did not receive message in time")
-				}
-				done <- struct{}{}
-			}()
-			bus.Publish(topic, message)
-			<-done
-
-			// Cleanup
-			close(listener)
-			bus.Off(listener, topic)
 		})
 
-		g.It("publishes message to all listeners", func() {
+		g.Describe("Publish", func() {
-			bus := NewBus()
+			const topic = "test"
+			const message = "this is a test message!"
 
-			g.Assert(bus.listeners[topic]).IsNotNil()
+			g.It("publishes message", func() {
-			g.Assert(len(bus.listeners[topic])).IsZero()
+				bus := NewBus()
-			listener := make(chan Event)
-			listener2 := make(chan Event)
-			listener3 := make(chan Event)
-			bus.On(listener, topic)
-			bus.On(listener2, topic)
-			bus.On(listener3, topic)
-			g.Assert(len(bus.listeners[topic])).Equal(3, "Listener was not registered")
 
-			done := make(chan struct{}, 1)
+				listener := make(chan []byte)
-			go func() {
+				bus.On(listener)
-				for i := 0; i < 3; i++ {
+
+				done := make(chan struct{}, 1)
+				go func() {
 					select {
-					case m := <-listener:
+					case v := <-listener:
-						g.Assert(m.Topic).Equal(topic)
+						m := MustDecode(v)
-						g.Assert(m.Data).Equal(message)
-					case m := <-listener2:
-						g.Assert(m.Topic).Equal(topic)
-						g.Assert(m.Data).Equal(message)
-					case m := <-listener3:
 						g.Assert(m.Topic).Equal(topic)
 						g.Assert(m.Data).Equal(message)
 					case <-time.After(1 * time.Second):
-						g.Fail("all listeners did not receive the message in time")
+						g.Fail("listener did not receive message in time")
-						i = 3
 					}
-				}
+					done <- struct{}{}
+				}()
+				bus.Publish(topic, message)
+				<-done
 
-				done <- struct{}{}
+				// Cleanup
-			}()
+				bus.Off(listener)
-			bus.Publish(topic, message)
+			})
-			<-done
 
-			// Cleanup
+			g.It("publishes message to all listeners", func() {
-			bus.Off(listener, topic)
+				bus := NewBus()
-			bus.Off(listener2, topic)
+
-			bus.Off(listener3, topic)
+				listener := make(chan []byte)
-			close(listener)
+				listener2 := make(chan []byte)
-			close(listener2)
+				listener3 := make(chan []byte)
-			close(listener3)
+				bus.On(listener)
+				bus.On(listener2)
+				bus.On(listener3)
+
+				done := make(chan struct{}, 1)
+				go func() {
+					for i := 0; i < 3; i++ {
+						select {
+						case v := <-listener:
+							m := MustDecode(v)
+							g.Assert(m.Topic).Equal(topic)
+							g.Assert(m.Data).Equal(message)
+						case v := <-listener2:
+							m := MustDecode(v)
+							g.Assert(m.Topic).Equal(topic)
+							g.Assert(m.Data).Equal(message)
+						case v := <-listener3:
+							m := MustDecode(v)
+							g.Assert(m.Topic).Equal(topic)
+							g.Assert(m.Data).Equal(message)
+						case <-time.After(1 * time.Second):
+							g.Fail("all listeners did not receive the message in time")
+							i = 3
+						}
+					}
+
+					done <- struct{}{}
+				}()
+				bus.Publish(topic, message)
+				<-done
+
+				// Cleanup
+				bus.Off(listener)
+				bus.Off(listener2)
+				bus.Off(listener3)
+			})
 		})
 	})
 }

go.mod

@@ -45,6 +45,10 @@ require (
 	gopkg.in/yaml.v2 v2.4.0
 )
 
+require github.com/goccy/go-json v0.9.4
+
+require golang.org/x/sys v0.0.0-20211110154304-99a53858aa08 // indirect
+
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
 	github.com/Microsoft/go-winio v0.5.0 // indirect
@@ -102,7 +106,6 @@ require (
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.7.0 // indirect
 	golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985 // indirect
-	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c // indirect
 	golang.org/x/term v0.0.0-20210615171337-6886f2dfbf5b // indirect
 	golang.org/x/text v0.3.6 // indirect
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac // indirect

parser/parser.go

@@ -2,7 +2,6 @@ package parser
 
 import (
 	"bufio"
-	"encoding/json"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -12,6 +11,7 @@ import (
 	"github.com/apex/log"
 	"github.com/beevik/etree"
 	"github.com/buger/jsonparser"
+	"github.com/goccy/go-json"
 	"github.com/icza/dyno"
 	"github.com/magiconair/properties"
 	"gopkg.in/ini.v1"
@@ -80,8 +80,8 @@ func (cp ConfigurationParser) String() string {
 	return string(cp)
 }
 
-// Defines a configuration file for the server startup. These will be looped over
+// ConfigurationFile defines a configuration file for the server startup. These
-// and modified before the server finishes booting.
+// will be looped over and modified before the server finishes booting.
 type ConfigurationFile struct {
 	FileName string                         `json:"file"`
 	Parser   ConfigurationParser            `json:"parser"`
@@ -92,12 +92,10 @@ type ConfigurationFile struct {
 	configuration []byte
 }
 
-// Custom unmarshaler for configuration files. If there is an error while parsing out the
+// UnmarshalJSON is a custom unmarshaler for configuration files. If there is an
-// replacements, don't fail the entire operation, just log a global warning so someone can
+// error while parsing out the replacements, don't fail the entire operation,
-// find the issue, and return an empty array of replacements.
+// just log a global warning so someone can find the issue, and return an empty
-//
+// array of replacements.
-// I imagine people will notice configuration replacement isn't working correctly and then
-// the logs should help better expose that issue.
 func (f *ConfigurationFile) UnmarshalJSON(data []byte) error {
 	var m map[string]*json.RawMessage
 	if err := json.Unmarshal(data, &m); err != nil {

remote/http.go

@@ -3,7 +3,6 @@ package remote
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -14,6 +13,7 @@ import (
 	"emperror.dev/errors"
 	"github.com/apex/log"
 	"github.com/cenkalti/backoff/v4"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/system"
 )

remote/types.go

@@ -1,11 +1,12 @@
 package remote
 
 import (
-	"encoding/json"
+	"bytes"
 	"regexp"
 	"strings"
 
 	"github.com/apex/log"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/parser"
 )
@@ -86,37 +87,38 @@ type SftpAuthResponse struct {
 type OutputLineMatcher struct {
 	// The raw string to match against. This may or may not be prefixed with
 	// regex: which indicates we want to match against the regex expression.
-	raw string
+	raw []byte
 	reg *regexp.Regexp
 }
 
-// Matches determines if a given string "s" matches the given line.
+// Matches determines if the provided byte string matches the given regex or
-func (olm *OutputLineMatcher) Matches(s string) bool {
+// raw string provided to the matcher.
+func (olm *OutputLineMatcher) Matches(s []byte) bool {
 	if olm.reg == nil {
-		return strings.Contains(s, olm.raw)
+		return bytes.Contains(s, olm.raw)
 	}
-
+	return olm.reg.Match(s)
-	return olm.reg.MatchString(s)
 }
 
 // String returns the matcher's raw comparison string.
 func (olm *OutputLineMatcher) String() string {
-	return olm.raw
+	return string(olm.raw)
 }
 
 // UnmarshalJSON unmarshals the startup lines into individual structs for easier
 // matching abilities.
 func (olm *OutputLineMatcher) UnmarshalJSON(data []byte) error {
-	if err := json.Unmarshal(data, &olm.raw); err != nil {
+	var r string
+	if err := json.Unmarshal(data, &r); err != nil {
 		return err
 	}
 
-	if strings.HasPrefix(olm.raw, "regex:") && len(olm.raw) > 6 {
+	olm.raw = []byte(r)
-		r, err := regexp.Compile(strings.TrimPrefix(olm.raw, "regex:"))
+	if bytes.HasPrefix(olm.raw, []byte("regex:")) && len(olm.raw) > 6 {
+		r, err := regexp.Compile(strings.TrimPrefix(string(olm.raw), "regex:"))
 		if err != nil {
-			log.WithField("error", err).WithField("raw", olm.raw).Warn("failed to compile output line marked as being regex")
+			log.WithField("error", err).WithField("raw", string(olm.raw)).Warn("failed to compile output line marked as being regex")
 		}
-
 		olm.reg = r
 	}
 

router/downloader/downloader.go

@@ -2,7 +2,6 @@ package downloader
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net"
@@ -15,6 +14,7 @@ import (
 
 	"emperror.dev/errors"
 	"github.com/google/uuid"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/server"
 )

router/middleware/middleware.go

@@ -218,19 +218,29 @@ func CaptureErrors() gin.HandlerFunc {
 // SetAccessControlHeaders sets the access request control headers on all of
 // the requests.
 func SetAccessControlHeaders() gin.HandlerFunc {
-	origins := config.Get().AllowedOrigins
+	cfg := config.Get()
-	location := config.Get().PanelLocation
+	origins := cfg.AllowedOrigins
+	location := cfg.PanelLocation
+	allowPrivateNetwork := cfg.AllowCORSPrivateNetwork
 
 	return func(c *gin.Context) {
+		c.Header("Access-Control-Allow-Origin", location)
 		c.Header("Access-Control-Allow-Credentials", "true")
 		c.Header("Access-Control-Allow-Methods", "GET, POST, PATCH, PUT, DELETE, OPTIONS")
+		c.Header("Access-Control-Allow-Headers", "Accept, Accept-Encoding, Authorization, Cache-Control, Content-Type, Content-Length, Origin, X-Real-IP, X-CSRF-Token")
+
+		// CORS for Private Networks (RFC1918)
+		// @see https://developer.chrome.com/blog/private-network-access-update/?utm_source=devtools
+		if allowPrivateNetwork {
+			c.Header("Access-Control-Request-Private-Network", "true")
+		}
+
 		// Maximum age allowable under Chromium v76 is 2 hours, so just use that since
 		// anything higher will be ignored (even if other browsers do allow higher values).
 		//
 		// @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Max-Age#Directives
 		c.Header("Access-Control-Max-Age", "7200")
-		c.Header("Access-Control-Allow-Origin", location)
+
-		c.Header("Access-Control-Allow-Headers", "Accept, Accept-Encoding, Authorization, Cache-Control, Content-Type, Content-Length, Origin, X-Real-IP, X-CSRF-Token")
 		// Validate that the request origin is coming from an allowed origin. Because you
 		// cannot set multiple values here we need to see if the origin is one of the ones
 		// that we allow, and if so return it explicitly. Otherwise, just return the default

router/router_server.go

@@ -52,7 +52,8 @@ func postServerPower(c *gin.Context) {
 	s := ExtractServer(c)
 
 	var data struct {
-		Action server.PowerAction `json:"action"`
+		Action      server.PowerAction `json:"action"`
+		WaitSeconds int                `json:"wait_seconds"`
 	}
 
 	if err := c.BindJSON(&data); err != nil {
@@ -83,12 +84,16 @@ func postServerPower(c *gin.Context) {
 	// we can immediately return a response from the server. Some of these actions
 	// can take quite some time, especially stopping or restarting.
 	go func(s *server.Server) {
-		if err := s.HandlePowerAction(data.Action, 30); err != nil {
+		if data.WaitSeconds < 0 || data.WaitSeconds > 300 {
+			data.WaitSeconds = 30
+		}
+		if err := s.HandlePowerAction(data.Action, data.WaitSeconds); err != nil {
 			if errors.Is(err, context.DeadlineExceeded) {
-				s.Log().WithField("action", data.Action).
+				s.Log().WithField("action", data.Action).WithField("error", err).Warn("could not process server power action")
-					Warn("could not acquire a lock while attempting to perform a power action")
+			} else if errors.Is(err, server.ErrIsRunning) {
+				// Do nothing, this isn't something we care about for logging,
 			} else {
-				s.Log().WithFields(log.Fields{"action": data, "error": err}).
+				s.Log().WithFields(log.Fields{"action": data.Action, "wait_seconds": data.WaitSeconds, "error": err}).
 					Error("encountered error processing a server power action in the background")
 			}
 		}
@@ -182,15 +187,7 @@ func deleteServer(c *gin.Context) {
 	// Immediately suspend the server to prevent a user from attempting
 	// to start it while this process is running.
 	s.Config().SetSuspended(true)
-
+	s.CleanupForDestroy()
-	// Stop all running background tasks for this server that are using the context on
-	// the server struct. This will cancel any running install processes for the server
-	// as well.
-	s.CtxCancel()
-	s.Events().Destroy()
-	s.LogSink().Destroy()
-	s.InstallSink().Destroy()
-	s.Websockets().CancelAll()
 
 	// Remove any pending remote file downloads for the server.
 	for _, dl := range downloader.ByServer(s.ID()) {

router/router_server_ws.go

@@ -2,11 +2,11 @@ package router
 
 import (
 	"context"
-	"encoding/json"
 	"time"
 
 	"github.com/gin-gonic/gin"
 	ws "github.com/gorilla/websocket"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/router/middleware"
 	"github.com/pterodactyl/wings/router/websocket"

router/router_transfer.go

@@ -178,7 +178,7 @@ func postServerArchive(c *gin.Context) {
 
 		// Ensure the server is offline. Sometimes a "No such container" error gets through
 		// which means the server is already stopped. We can ignore that.
-		if err := s.Environment.WaitForStop(60, false); err != nil && !strings.Contains(strings.ToLower(err.Error()), "no such container") {
+		if err := s.Environment.WaitForStop(s.Context(), time.Minute, false); err != nil && !strings.Contains(strings.ToLower(err.Error()), "no such container") {
 			sendTransferLog("Failed to stop server, aborting transfer..")
 			l.WithField("error", err).Error("failed to stop server")
 			return

router/tokens/websocket.go

@@ -1,13 +1,13 @@
 package tokens
 
 import (
-	"encoding/json"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/apex/log"
 	"github.com/gbrlsnchs/jwt/v3"
+	"github.com/goccy/go-json"
 )
 
 // The time at which Wings was booted. No JWT's created before this time are allowed to

router/websocket/listeners.go

@@ -2,12 +2,14 @@ package websocket
 
 import (
 	"context"
-	"encoding/json"
 	"sync"
 	"time"
 
 	"emperror.dev/errors"
+	"github.com/goccy/go-json"
 	"github.com/pterodactyl/wings/events"
+	"github.com/pterodactyl/wings/system"
+
 	"github.com/pterodactyl/wings/server"
 )
 
@@ -87,12 +89,13 @@ func (h *Handler) listenForServerEvents(ctx context.Context) error {
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	eventChan := make(chan events.Event)
+	eventChan := make(chan []byte)
-	logOutput := make(chan []byte)
+	logOutput := make(chan []byte, 8)
-	installOutput := make(chan []byte)
+	installOutput := make(chan []byte, 4)
-	h.server.Events().On(eventChan, e...)
+
-	h.server.LogSink().On(logOutput)
+	h.server.Events().On(eventChan) // TODO: make a sinky
-	h.server.InstallSink().On(installOutput)
+	h.server.Sink(system.LogSink).On(logOutput)
+	h.server.Sink(system.InstallSink).On(installOutput)
 
 	onError := func(evt string, err2 error) {
 		h.Logger().WithField("event", evt).WithField("error", err2).Error("failed to send event over server websocket")
@@ -109,19 +112,23 @@ func (h *Handler) listenForServerEvents(ctx context.Context) error {
 		select {
 		case <-ctx.Done():
 			break
-		case e := <-logOutput:
+		case b := <-logOutput:
-			sendErr := h.SendJson(Message{Event: server.ConsoleOutputEvent, Args: []string{string(e)}})
+			sendErr := h.SendJson(Message{Event: server.ConsoleOutputEvent, Args: []string{string(b)}})
 			if sendErr == nil {
 				continue
 			}
 			onError(server.ConsoleOutputEvent, sendErr)
-		case e := <-installOutput:
+		case b := <-installOutput:
-			sendErr := h.SendJson(Message{Event: server.InstallOutputEvent, Args: []string{string(e)}})
+			sendErr := h.SendJson(Message{Event: server.InstallOutputEvent, Args: []string{string(b)}})
 			if sendErr == nil {
 				continue
 			}
 			onError(server.InstallOutputEvent, sendErr)
-		case e := <-eventChan:
+		case b := <-eventChan:
+			var e events.Event
+			if err := events.DecodeTo(b, &e); err != nil {
+				continue
+			}
 			var sendErr error
 			message := Message{Event: e.Topic}
 			if str, ok := e.Data.(string); ok {
@@ -146,12 +153,10 @@ func (h *Handler) listenForServerEvents(ctx context.Context) error {
 		break
 	}
 
-	h.server.Events().Off(eventChan, e...)
+	// These functions will automatically close the channel if it hasn't been already.
-	h.server.InstallSink().Off(logOutput)
+	h.server.Events().Off(eventChan)
-	h.server.InstallSink().Off(installOutput)
+	h.server.Sink(system.LogSink).Off(logOutput)
-	close(eventChan)
+	h.server.Sink(system.InstallSink).Off(installOutput)
-	close(logOutput)
-	close(installOutput)
 
 	// If the internal context is stopped it is either because the parent context
 	// got canceled or because we ran into an error. If the "err" variable is nil

router/websocket/websocket.go

@@ -2,7 +2,6 @@ package websocket
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"strings"
@@ -12,8 +11,10 @@ import (
 	"emperror.dev/errors"
 	"github.com/apex/log"
 	"github.com/gbrlsnchs/jwt/v3"
+	"github.com/goccy/go-json"
 	"github.com/google/uuid"
 	"github.com/gorilla/websocket"
+	"github.com/pterodactyl/wings/system"
 
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
@@ -353,7 +354,7 @@ func (h *Handler) HandleInbound(ctx context.Context, m Message) error {
 			}
 
 			err := h.server.HandlePowerAction(action)
-			if errors.Is(err, context.DeadlineExceeded) {
+			if errors.Is(err, system.ErrLockerLocked) {
 				m, _ := h.GetErrorMessage("another power action is currently being processed for this server, please try again later")
 
 				_ = h.SendJson(Message{

server/backup.go

@@ -142,7 +142,7 @@ func (s *Server) RestoreBackup(b backup.BackupInterface, reader io.ReadCloser) (
 	// instance, otherwise you'll likely hit all types of write errors due to the
 	// server being suspended.
 	if s.Environment.State() != environment.ProcessOfflineState {
-		if err = s.Environment.WaitForStop(120, false); err != nil {
+		if err = s.Environment.WaitForStop(s.Context(), time.Minute*2, false); err != nil {
 			if !client.IsErrNotFound(err) {
 				return errors.WrapIf(err, "server/backup: restore: failed to wait for container stop")
 			}

server/config_parser.go

@@ -6,12 +6,14 @@ import (
 	"github.com/gammazero/workerpool"
 )
 
-// Parent function that will update all of the defined configuration files for a server
+// UpdateConfigurationFiles updates all of the defined configuration files for
-// automatically to ensure that they always use the specified values.
+// a server automatically to ensure that they always use the specified values.
 func (s *Server) UpdateConfigurationFiles() {
 	pool := workerpool.New(runtime.NumCPU())
 
+	s.Log().Debug("acquiring process configuration files...")
 	files := s.ProcessConfiguration().ConfigurationFiles
+	s.Log().Debug("acquired process configuration files")
 	for _, cf := range files {
 		f := cf
 
@@ -26,6 +28,8 @@ func (s *Server) UpdateConfigurationFiles() {
 			if err := f.Parse(p, false); err != nil {
 				s.Log().WithField("error", err).Error("failed to parse and update server configuration file")
 			}
+
+			s.Log().WithField("path", f.FileName).Debug("finished processing server configuration file")
 		})
 	}
 

server/console.go

@@ -1,15 +1,11 @@
 package server
 
 import (
-	"context"
 	"fmt"
 	"sync"
-	"sync/atomic"
 	"time"
 
-	"emperror.dev/errors"
 	"github.com/mitchellh/colorstring"
-
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/system"
 )
@@ -18,118 +14,8 @@ import (
 // the configuration every time we need to send output along to the websocket for
 // a server.
 var appName string
-
 var appNameSync sync.Once
 
-var ErrTooMuchConsoleData = errors.New("console is outputting too much data")
-
-type ConsoleThrottler struct {
-	mu sync.Mutex
-	config.ConsoleThrottles
-
-	// The total number of activations that have occurred thus far.
-	activations uint64
-
-	// The total number of lines that have been sent since the last reset timer period.
-	count uint64
-
-	// Wether or not the console output is being throttled. It is up to calling code to
-	// determine what to do if it is.
-	isThrottled *system.AtomicBool
-
-	// The total number of lines processed so far during the given time period.
-	timerCancel *context.CancelFunc
-}
-
-// Resets the state of the throttler.
-func (ct *ConsoleThrottler) Reset() {
-	atomic.StoreUint64(&ct.count, 0)
-	atomic.StoreUint64(&ct.activations, 0)
-	ct.isThrottled.Store(false)
-}
-
-// Triggers an activation for a server. You can also decrement the number of activations
-// by passing a negative number.
-func (ct *ConsoleThrottler) markActivation(increment bool) uint64 {
-	if !increment {
-		if atomic.LoadUint64(&ct.activations) == 0 {
-			return 0
-		}
-
-		// This weird dohicky subtracts 1 from the activation count.
-		return atomic.AddUint64(&ct.activations, ^uint64(0))
-	}
-
-	return atomic.AddUint64(&ct.activations, 1)
-}
-
-// Determines if the console is currently being throttled. Calls to this function can be used to
-// determine if output should be funneled along to the websocket processes.
-func (ct *ConsoleThrottler) Throttled() bool {
-	return ct.isThrottled.Load()
-}
-
-// Starts a timer that runs in a seperate thread and will continually decrement the lines processed
-// and number of activations, regardless of the current console message volume. All of the timers
-// are canceled if the context passed through is canceled.
-func (ct *ConsoleThrottler) StartTimer(ctx context.Context) {
-	system.Every(ctx, time.Duration(int64(ct.LineResetInterval))*time.Millisecond, func(_ time.Time) {
-		ct.isThrottled.Store(false)
-		atomic.StoreUint64(&ct.count, 0)
-	})
-
-	system.Every(ctx, time.Duration(int64(ct.DecayInterval))*time.Millisecond, func(_ time.Time) {
-		ct.markActivation(false)
-	})
-}
-
-// Handles output from a server's console. This code ensures that a server is not outputting
-// an excessive amount of data to the console that could indicate a malicious or run-away process
-// and lead to performance issues for other users.
-//
-// This was much more of a problem for the NodeJS version of the daemon which struggled to handle
-// large volumes of output. However, this code is much more performant so I generally feel a lot
-// better about it's abilities.
-//
-// However, extreme output is still somewhat of a DoS attack vector against this software since we
-// are still logging it to the disk temporarily and will want to avoid dumping a huge amount of
-// data all at once. These values are all configurable via the wings configuration file, however the
-// defaults have been in the wild for almost two years at the time of this writing, so I feel quite
-// confident in them.
-//
-// This function returns an error if the server should be stopped due to violating throttle constraints
-// and a boolean value indicating if a throttle is being violated when it is checked.
-func (ct *ConsoleThrottler) Increment(onTrigger func()) error {
-	if !ct.Enabled {
-		return nil
-	}
-
-	// Increment the line count and if we have now output more lines than are allowed, trigger a throttle
-	// activation. Once the throttle is triggered and has passed the kill at value we will trigger a server
-	// stop automatically.
-	if atomic.AddUint64(&ct.count, 1) >= ct.Lines && !ct.Throttled() {
-		ct.isThrottled.Store(true)
-		if ct.markActivation(true) >= ct.MaximumTriggerCount {
-			return ErrTooMuchConsoleData
-		}
-
-		onTrigger()
-	}
-
-	return nil
-}
-
-// Returns the throttler instance for the server or creates a new one.
-func (s *Server) Throttler() *ConsoleThrottler {
-	s.throttleOnce.Do(func() {
-		s.throttler = &ConsoleThrottler{
-			isThrottled:      system.NewAtomicBool(false),
-			ConsoleThrottles: config.Get().Throttles,
-		}
-	})
-	return s.throttler
-}
-
 // PublishConsoleOutputFromDaemon sends output to the server console formatted
 // to appear correctly as being sent from Wings.
 func (s *Server) PublishConsoleOutputFromDaemon(data string) {
@@ -141,3 +27,55 @@ func (s *Server) PublishConsoleOutputFromDaemon(data string) {
 		colorstring.Color(fmt.Sprintf("[yellow][bold][%s Daemon]:[default] %s", appName, data)),
 	)
 }
+
+// Throttler returns the throttler instance for the server or creates a new one.
+func (s *Server) Throttler() *ConsoleThrottle {
+	s.throttleOnce.Do(func() {
+		throttles := config.Get().Throttles
+		period := time.Duration(throttles.Period) * time.Millisecond
+
+		s.throttler = newConsoleThrottle(throttles.Lines, period)
+		s.throttler.strike = func() {
+			s.PublishConsoleOutputFromDaemon(fmt.Sprintf("Server is outputting console data too quickly -- throttling..."))
+		}
+	})
+	return s.throttler
+}
+
+type ConsoleThrottle struct {
+	limit  *system.Rate
+	lock   *system.Locker
+	strike func()
+}
+
+func newConsoleThrottle(lines uint64, period time.Duration) *ConsoleThrottle {
+	return &ConsoleThrottle{
+		limit: system.NewRate(lines, period),
+		lock:  system.NewLocker(),
+	}
+}
+
+// Allow checks if the console is allowed to process more output data, or if too
+// much has already been sent over the line. If there is too much output the
+// strike callback function is triggered, but only if it has not already been
+// triggered at this point in the process.
+//
+// If output is allowed, the lock on the throttler is released and the next time
+// it is triggered the strike function will be re-executed.
+func (ct *ConsoleThrottle) Allow() bool {
+	if !ct.limit.Try() {
+		if err := ct.lock.Acquire(); err == nil {
+			if ct.strike != nil {
+				ct.strike()
+			}
+		}
+		return false
+	}
+	ct.lock.Release()
+	return true
+}
+
+// Reset resets the console throttler internal rate limiter and overage counter.
+func (ct *ConsoleThrottle) Reset() {
+	ct.limit.Reset()
+}

server/console_test.go

@@ -0,0 +1,62 @@
+package server
+
+import (
+	"testing"
+	"time"
+
+	"github.com/franela/goblin"
+)
+
+func TestName(t *testing.T) {
+	g := goblin.Goblin(t)
+
+	g.Describe("ConsoleThrottler", func() {
+		g.It("keeps count of the number of overages in a time period", func() {
+			t := newConsoleThrottle(1, time.Second)
+			g.Assert(t.Allow()).IsTrue()
+			g.Assert(t.Allow()).IsFalse()
+			g.Assert(t.Allow()).IsFalse()
+		})
+
+		g.It("calls strike once per time period", func() {
+			t := newConsoleThrottle(1, time.Millisecond * 20)
+
+			var times int
+			t.strike = func() {
+				times = times + 1
+			}
+
+			t.Allow()
+			t.Allow()
+			t.Allow()
+			time.Sleep(time.Millisecond * 100)
+			t.Allow()
+			t.Reset()
+			t.Allow()
+			t.Allow()
+			t.Allow()
+
+			g.Assert(times).Equal(2)
+		})
+
+		g.It("is properly reset", func() {
+			t := newConsoleThrottle(10, time.Second)
+
+			for i := 0; i < 10; i++ {
+				g.Assert(t.Allow()).IsTrue()
+			}
+			g.Assert(t.Allow()).IsFalse()
+			t.Reset()
+			g.Assert(t.Allow()).IsTrue()
+		})
+	})
+}
+
+func BenchmarkConsoleThrottle(b *testing.B) {
+	t := newConsoleThrottle(10, time.Millisecond * 10)
+
+	b.ReportAllocs()
+    for i := 0; i < b.N; i++ {
+        t.Allow()
+    }
+}

server/events.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"github.com/pterodactyl/wings/events"
+	"github.com/pterodactyl/wings/system"
 )
 
 // Defines all of the possible output events for a server.
@@ -20,7 +21,7 @@ const (
 	TransferStatusEvent         = "transfer status"
 )
 
-// Returns the server's emitter instance.
+// Events returns the server's emitter instance.
 func (s *Server) Events() *events.Bus {
 	s.emitterLock.Lock()
 	defer s.emitterLock.Unlock()
@@ -31,3 +32,24 @@ func (s *Server) Events() *events.Bus {
 
 	return s.emitter
 }
+
+// Sink returns the instantiated and named sink for a server. If the sink has
+// not been configured yet this function will cause a panic condition.
+func (s *Server) Sink(name system.SinkName) *system.SinkPool {
+	sink, ok := s.sinks[name]
+	if !ok {
+		s.Log().Fatalf("attempt to access nil sink: %s", name)
+	}
+	return sink
+}
+
+// DestroyAllSinks iterates over all of the sinks configured for the server and
+// destroys their instances. Note that this will cause a panic if you attempt
+// to call Server.Sink() again after. This function is only used when a server
+// is being deleted from the system.
+func (s *Server) DestroyAllSinks() {
+	s.Log().Info("destroying all registered sinks for server instance")
+	for _, sink := range s.sinks {
+		sink.Destroy()
+	}
+}

server/filesystem/stat.go

@@ -1,12 +1,12 @@
 package filesystem
 
 import (
-	"encoding/json"
 	"os"
 	"strconv"
 	"time"
 
 	"github.com/gabriel-vasile/mimetype"
+	"github.com/goccy/go-json"
 )
 
 type Stat struct {

server/install.go

@@ -10,6 +10,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
 	"emperror.dev/errors"
 	"github.com/apex/log"
@@ -17,23 +18,23 @@ import (
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/client"
-
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
 	"github.com/pterodactyl/wings/remote"
 	"github.com/pterodactyl/wings/system"
 )
 
-// Executes the installation stack for a server process. Bubbles any errors up to the calling
+// Install executes the installation stack for a server process. Bubbles any
-// function which should handle contacting the panel to notify it of the server state.
+// errors up to the calling function which should handle contacting the panel to
+// notify it of the server state.
 //
-// Pass true as the first argument in order to execute a server sync before the process to
+// Pass true as the first argument in order to execute a server sync before the
-// ensure the latest information is used.
+// process to ensure the latest information is used.
 func (s *Server) Install(sync bool) error {
 	if sync {
 		s.Log().Info("syncing server state with remote source before executing installation process")
 		if err := s.Sync(); err != nil {
-			return err
+			return errors.WrapIf(err, "install: failed to sync server state with Panel")
 		}
 	}
 
@@ -57,7 +58,7 @@ func (s *Server) Install(sync bool) error {
 		// error to this log entry. Otherwise ignore it in this log since whatever is calling
 		// this function should handle the error and will end up logging the same one.
 		if err == nil {
-			l.WithField("error", serr)
+			l.WithField("error", err)
 		}
 
 		l.Warn("failed to notify panel of server install state")
@@ -71,7 +72,7 @@ func (s *Server) Install(sync bool) error {
 	// the install is completed.
 	s.Events().Publish(InstallCompletedEvent, "")
 
-	return err
+	return errors.WithStackIf(err)
 }
 
 // Reinstalls a server's software by utilizing the install script for the server egg. This
@@ -79,8 +80,8 @@ func (s *Server) Install(sync bool) error {
 func (s *Server) Reinstall() error {
 	if s.Environment.State() != environment.ProcessOfflineState {
 		s.Log().Debug("waiting for server instance to enter a stopped state")
-		if err := s.Environment.WaitForStop(10, true); err != nil {
+		if err := s.Environment.WaitForStop(s.Context(), time.Second*10, true); err != nil {
-			return err
+			return errors.WrapIf(err, "install: failed to stop running environment")
 		}
 	}
 
@@ -110,9 +111,7 @@ func (s *Server) internalInstall() error {
 type InstallationProcess struct {
 	Server *Server
 	Script *remote.InstallationScript
-
+	client *client.Client
-	client  *client.Client
-	context context.Context
 }
 
 // Generates a new installation process struct that will be used to create containers,
@@ -127,7 +126,6 @@ func NewInstallationProcess(s *Server, script *remote.InstallationScript) (*Inst
 		return nil, err
 	} else {
 		proc.client = c
-		proc.context = s.Context()
 	}
 
 	return proc, nil
@@ -157,7 +155,7 @@ func (s *Server) SetRestoring(state bool) {
 
 // Removes the installer container for the server.
 func (ip *InstallationProcess) RemoveContainer() error {
-	err := ip.client.ContainerRemove(ip.context, ip.Server.ID()+"_installer", types.ContainerRemoveOptions{
+	err := ip.client.ContainerRemove(ip.Server.Context(), ip.Server.ID()+"_installer", types.ContainerRemoveOptions{
 		RemoveVolumes: true,
 		Force:         true,
 	})
@@ -167,11 +165,10 @@ func (ip *InstallationProcess) RemoveContainer() error {
 	return nil
 }
 
-// Runs the installation process, this is done as in a background thread. This will configure
+// Run runs the installation process, this is done as in a background thread.
-// the required environment, and then spin up the installation container.
+// This will configure the required environment, and then spin up the
-//
+// installation container. Once the container finishes installing the results
-// Once the container finishes installing the results will be stored in an installation
+// are stored in an installation log in the server's configuration directory.
-// log in the server's configuration directory.
 func (ip *InstallationProcess) Run() error {
 	ip.Server.Log().Debug("acquiring installation process lock")
 	if !ip.Server.installing.SwapIf(true) {
@@ -207,7 +204,7 @@ func (ip *InstallationProcess) Run() error {
 
 // Returns the location of the temporary data for the installation process.
 func (ip *InstallationProcess) tempDir() string {
-	return filepath.Join(os.TempDir(), "pterodactyl/", ip.Server.ID())
+	return filepath.Join(config.Get().System.TmpDirectory, ip.Server.ID())
 }
 
 // Writes the installation script to a temporary file on the host machine so that it
@@ -267,9 +264,9 @@ func (ip *InstallationProcess) pullInstallationImage() error {
 		imagePullOptions.RegistryAuth = b64
 	}
 
-	r, err := ip.client.ImagePull(context.Background(), ip.Script.ContainerImage, imagePullOptions)
+	r, err := ip.client.ImagePull(ip.Server.Context(), ip.Script.ContainerImage, imagePullOptions)
 	if err != nil {
-		images, ierr := ip.client.ImageList(context.Background(), types.ImageListOptions{})
+		images, ierr := ip.client.ImageList(ip.Server.Context(), types.ImageListOptions{})
 		if ierr != nil {
 			// Well damn, something has gone really wrong here, just go ahead and abort there
 			// isn't much anything we can do to try and self-recover from this.
@@ -312,9 +309,10 @@ func (ip *InstallationProcess) pullInstallationImage() error {
 	return nil
 }
 
-// Runs before the container is executed. This pulls down the required docker container image
+// BeforeExecute runs before the container is executed. This pulls down the
-// as well as writes the installation script to the disk. This process is executed in an async
+// required docker container image as well as writes the installation script to
-// manner, if either one fails the error is returned.
+// the disk. This process is executed in an async manner, if either one fails
+// the error is returned.
 func (ip *InstallationProcess) BeforeExecute() error {
 	if err := ip.writeScriptToDisk(); err != nil {
 		return errors.WithMessage(err, "failed to write installation script to disk")
@@ -340,7 +338,7 @@ func (ip *InstallationProcess) AfterExecute(containerId string) error {
 	defer ip.RemoveContainer()
 
 	ip.Server.Log().WithField("container_id", containerId).Debug("pulling installation logs for server")
-	reader, err := ip.client.ContainerLogs(ip.context, containerId, types.ContainerLogsOptions{
+	reader, err := ip.client.ContainerLogs(ip.Server.Context(), containerId, types.ContainerLogsOptions{
 		ShowStdout: true,
 		ShowStderr: true,
 		Follow:     false,
@@ -395,12 +393,13 @@ func (ip *InstallationProcess) AfterExecute(containerId string) error {
 	return nil
 }
 
-// Executes the installation process inside a specially created docker container.
+// Execute executes the installation process inside a specially created docker
+// container.
 func (ip *InstallationProcess) Execute() (string, error) {
 	// Create a child context that is canceled once this function is done running. This
 	// will also be canceled if the parent context (from the Server struct) is canceled
 	// which occurs if the server is deleted.
-	ctx, cancel := context.WithCancel(ip.context)
+	ctx, cancel := context.WithCancel(ip.Server.Context())
 	defer cancel()
 
 	conf := &container.Config{
@@ -507,22 +506,19 @@ func (ip *InstallationProcess) Execute() (string, error) {
 	return r.ID, nil
 }
 
-// Streams the output of the installation process to a log file in the server configuration
+// StreamOutput streams the output of the installation process to a log file in
-// directory, as well as to a websocket listener so that the process can be viewed in
+// the server configuration directory, as well as to a websocket listener so
-// the panel by administrators.
+// that the process can be viewed in the panel by administrators.
 func (ip *InstallationProcess) StreamOutput(ctx context.Context, id string) error {
-	reader, err := ip.client.ContainerLogs(ctx, id, types.ContainerLogsOptions{
+	opts := types.ContainerLogsOptions{ShowStdout: true, ShowStderr: true, Follow: true}
-		ShowStdout: true,
+	reader, err := ip.client.ContainerLogs(ctx, id, opts)
-		ShowStderr: true,
-		Follow:     true,
-	})
 	if err != nil {
 		return err
 	}
 	defer reader.Close()
 
-	err = system.ScanReader(reader, ip.Server.InstallSink().Push)
+	err = system.ScanReader(reader, ip.Server.Sink(system.InstallSink).Push)
-	if err != nil {
+	if err != nil && !errors.Is(err, context.Canceled) {
 		ip.Server.Log().WithFields(log.Fields{"container_id": id, "error": err}).Warn("error processing install output lines")
 	}
 	return nil

server/listeners.go

@@ -1,15 +1,17 @@
 package server
 
 import (
+	"bytes"
 	"regexp"
 	"strconv"
 	"sync"
+	"time"
 
 	"github.com/apex/log"
-
-	"github.com/pterodactyl/wings/config"
-	"github.com/pterodactyl/wings/environment"
 	"github.com/pterodactyl/wings/events"
+	"github.com/pterodactyl/wings/system"
+
+	"github.com/pterodactyl/wings/environment"
 	"github.com/pterodactyl/wings/remote"
 )
 
@@ -44,136 +46,133 @@ func (dsl *diskSpaceLimiter) Reset() {
 func (dsl *diskSpaceLimiter) Trigger() {
 	dsl.o.Do(func() {
 		dsl.server.PublishConsoleOutputFromDaemon("Server is exceeding the assigned disk space limit, stopping process now.")
-		if err := dsl.server.Environment.WaitForStop(60, true); err != nil {
+		if err := dsl.server.Environment.WaitForStop(dsl.server.Context(), time.Minute, true); err != nil {
 			dsl.server.Log().WithField("error", err).Error("failed to stop server after exceeding space limit!")
 		}
 	})
 }
 
+// processConsoleOutputEvent handles output from a server's Docker container
+// and runs through different limiting logic to ensure that spam console output
+// does not cause negative effects to the system. This will also monitor the
+// output lines to determine if the server is started yet, and if the output is
+// not being throttled, will send the data over to the websocket.
 func (s *Server) processConsoleOutputEvent(v []byte) {
-	t := s.Throttler()
+	// Always process the console output, but do this in a seperate thread since we
-	err := t.Increment(func() {
+	// don't really care about side-effects from this call, and don't want it to block
-		s.PublishConsoleOutputFromDaemon("Your server is outputting too much data and is being throttled.")
+	// the console sending logic.
-	})
+	go s.onConsoleOutput(v)
-	// An error is only returned if the server has breached the thresholds set.
-	if err != nil {
-		// If the process is already stopping, just let it continue with that action rather than attempting
-		// to terminate again.
-		if s.Environment.State() != environment.ProcessStoppingState {
-			s.Environment.SetState(environment.ProcessStoppingState)
 
-			go func() {
+	// If the console is being throttled, do nothing else with it, we don't want
-				s.Log().Warn("stopping server instance, violating throttle limits")
+	// to waste time. This code previously terminated server instances after violating
-				s.PublishConsoleOutputFromDaemon("Your server is being stopped for outputting too much data in a short period of time.")
+	// different throttle limits. That code was clunky and difficult to reason about,
-
+	// in addition to being a consistent pain point for users.
-				// Completely skip over server power actions and terminate the running instance. This gives the
+	//
-				// server 15 seconds to finish stopping gracefully before it is forcefully terminated.
+	// In the interest of building highly efficient software, that code has been removed
-				if err := s.Environment.WaitForStop(config.Get().Throttles.StopGracePeriod, true); err != nil {
+	// here, and we'll rely on the host to detect bad actors through their own means.
-					// If there is an error set the process back to running so that this throttler is called
+	if !s.Throttler().Allow() {
-					// again and hopefully kills the server.
+		return
-					if s.Environment.State() != environment.ProcessOfflineState {
-						s.Environment.SetState(environment.ProcessRunningState)
-					}
-
-					s.Log().WithField("error", err).Error("failed to terminate environment after triggering throttle")
-				}
-			}()
-		}
 	}
 
-	// If we are not throttled, go ahead and output the data.
+	s.Sink(system.LogSink).Push(v)
-	if !t.Throttled() {
-		s.LogSink().Push(v)
-	}
-
-	// Also pass the data along to the console output channel.
-	s.onConsoleOutput(string(v))
 }
 
-// StartEventListeners adds all the internal event listeners we want to use for a server. These listeners can only be
+// StartEventListeners adds all the internal event listeners we want to use for
-// removed by deleting the server as they should last for the duration of the process' lifetime.
+// a server. These listeners can only be removed by deleting the server as they
+// should last for the duration of the process' lifetime.
 func (s *Server) StartEventListeners() {
-	state := make(chan events.Event)
+	c := make(chan []byte, 8)
-	stats := make(chan events.Event)
+	limit := newDiskLimiter(s)
-	docker := make(chan events.Event)
+
+	s.Log().Debug("registering event listeners: console, state, resources...")
+	s.Environment.Events().On(c)
+	s.Environment.SetLogCallback(s.processConsoleOutputEvent)
 
 	go func() {
-		l := newDiskLimiter(s)
-
 		for {
 			select {
-			case e := <-state:
+			case v := <-c:
-				go func() {
+				go func(v []byte, limit *diskSpaceLimiter) {
-					// Reset the throttler when the process is started.
+					var e events.Event
-					if e.Data == environment.ProcessStartingState {
+					if err := events.DecodeTo(v, &e); err != nil {
-						l.Reset()
+						return
-						s.Throttler().Reset()
 					}
-
-					s.OnStateChange()
-				}()
-			case e := <-stats:
-				go func() {
-					// Update the server resource tracking object with the resources we got here.
-					s.resources.mu.Lock()
-					s.resources.Stats = e.Data.(environment.Stats)
-					s.resources.mu.Unlock()
-
-					// If there is no disk space available at this point, trigger the server disk limiter logic
-					// which will start to stop the running instance.
-					if !s.Filesystem().HasSpaceAvailable(true) {
-						l.Trigger()
-					}
-
-					s.emitProcUsage()
-				}()
-			case e := <-docker:
-				go func() {
 					switch e.Topic {
+					case environment.ResourceEvent:
+						{
+							var stats struct {
+								Topic string
+								Data  environment.Stats
+							}
+							if err := events.DecodeTo(v, &stats); err != nil {
+								s.Log().WithField("error", err).Warn("failed to decode server resource event")
+								return
+							}
+							s.resources.UpdateStats(stats.Data)
+							// If there is no disk space available at this point, trigger the server
+							// disk limiter logic which will start to stop the running instance.
+							if !s.Filesystem().HasSpaceAvailable(true) {
+								limit.Trigger()
+							}
+							s.Events().Publish(StatsEvent, s.Proc())
+						}
+					case environment.StateChangeEvent:
+						{
+							// Reset the throttler when the process is started.
+							if e.Data == environment.ProcessStartingState {
+								limit.Reset()
+								s.Throttler().Reset()
+							}
+							s.OnStateChange()
+						}
 					case environment.DockerImagePullStatus:
 						s.Events().Publish(InstallOutputEvent, e.Data)
 					case environment.DockerImagePullStarted:
 						s.PublishConsoleOutputFromDaemon("Pulling Docker container image, this could take a few minutes to complete...")
-					default:
+					case environment.DockerImagePullCompleted:
 						s.PublishConsoleOutputFromDaemon("Finished pulling Docker container image")
+					default:
 					}
-				}()
+				}(v, limit)
+			case <-s.Context().Done():
+				return
 			}
 		}
 	}()
-
-	s.Log().Debug("registering event listeners: console, state, resources...")
-	s.Environment.SetLogCallback(s.processConsoleOutputEvent)
-	s.Environment.Events().On(state, environment.StateChangeEvent)
-	s.Environment.Events().On(stats, environment.ResourceEvent)
-	s.Environment.Events().On(docker, dockerEvents...)
 }
 
 var stripAnsiRegex = regexp.MustCompile("[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))")
 
 // Custom listener for console output events that will check if the given line
 // of output matches one that should mark the server as started or not.
-func (s *Server) onConsoleOutput(data string) {
+func (s *Server) onConsoleOutput(data []byte) {
-	// Get the server's process configuration.
+	if s.Environment.State() != environment.ProcessStartingState && !s.IsRunning() {
+		return
+	}
+
 	processConfiguration := s.ProcessConfiguration()
 
+	// Make a copy of the data provided since it is by reference, otherwise you'll
+	// potentially introduce a race condition by modifying the value.
+	v := make([]byte, len(data))
+	copy(v, data)
+
 	// Check if the server is currently starting.
 	if s.Environment.State() == environment.ProcessStartingState {
 		// Check if we should strip ansi color codes.
 		if processConfiguration.Startup.StripAnsi {
-			// Strip ansi color codes from the data string.
+			v = stripAnsiRegex.ReplaceAll(v, []byte(""))
-			data = stripAnsiRegex.ReplaceAllString(data, "")
 		}
 
 		// Iterate over all the done lines.
 		for _, l := range processConfiguration.Startup.Done {
-			if !l.Matches(data) {
+			if !l.Matches(v) {
 				continue
 			}
 
 			s.Log().WithFields(log.Fields{
 				"match":   l.String(),
-				"against": strconv.QuoteToASCII(data),
+				"against": strconv.QuoteToASCII(string(v)),
 			}).Debug("detected server in running state based on console line output")
 
 			// If the specific line of output is one that would mark the server as started,
@@ -190,7 +189,7 @@ func (s *Server) onConsoleOutput(data string) {
 	if s.IsRunning() {
 		stop := processConfiguration.Stop
 
-		if stop.Type == remote.ProcessStopCommand && data == stop.Value {
+		if stop.Type == remote.ProcessStopCommand && bytes.Equal(v, []byte(stop.Value)) {
 			s.Environment.SetState(environment.ProcessOfflineState)
 		}
 	}

server/manager.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -14,6 +13,7 @@ import (
 	"emperror.dev/errors"
 	"github.com/apex/log"
 	"github.com/gammazero/workerpool"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
@@ -199,7 +199,6 @@ func (m *Manager) InitServer(data remote.ServerConfigurationResponse) (*Server,
 	} else {
 		s.Environment = env
 		s.StartEventListeners()
-		s.Throttler().StartTimer(s.Context())
 	}
 
 	// If the server's data directory exists, force disk usage calculation.

server/power.go

@@ -2,12 +2,12 @@ package server
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"time"
 
 	"emperror.dev/errors"
-	"golang.org/x/sync/semaphore"
+	"github.com/google/uuid"
-
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
 )
@@ -40,19 +40,10 @@ func (pa PowerAction) IsStart() bool {
 	return pa == PowerActionStart || pa == PowerActionRestart
 }
 
-// ExecutingPowerAction checks if there is currently a power action being processed for the server.
+// ExecutingPowerAction checks if there is currently a power action being
+// processed for the server.
 func (s *Server) ExecutingPowerAction() bool {
-	if s.powerLock == nil {
+	return s.powerLock.IsLocked()
-		return false
-	}
-
-	ok := s.powerLock.TryAcquire(1)
-	if ok {
-		s.powerLock.Release(1)
-	}
-
-	// Remember, if we acquired a lock it means nothing was running.
-	return !ok
 }
 
 // HandlePowerAction is a helper function that can receive a power action and then process the
@@ -63,22 +54,29 @@ func (s *Server) ExecutingPowerAction() bool {
 // function rather than making direct calls to the start/stop/restart functions on the
 // environment struct.
 func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error {
-	if s.IsInstalling() {
+	if s.IsInstalling() || s.IsTransferring() || s.IsRestoring() {
+		if s.IsRestoring() {
+			return ErrServerIsRestoring
+		} else if s.IsTransferring() {
+			return ErrServerIsTransferring
+		}
 		return ErrServerIsInstalling
 	}
 
-	if s.IsTransferring() {
+	lockId, _ := uuid.NewUUID()
-		return ErrServerIsTransferring
+	log := s.Log().WithField("lock_id", lockId.String()).WithField("action", action)
+
+	cleanup := func() {
+		log.Info("releasing exclusive lock for power action")
+		s.powerLock.Release()
 	}
 
-	if s.IsRestoring() {
+	var wait int
-		return ErrServerIsRestoring
+	if len(waitSeconds) > 0 && waitSeconds[0] > 0 {
-	}
+		wait = waitSeconds[0]
-
-	if s.powerLock == nil {
-		s.powerLock = semaphore.NewWeighted(1)
 	}
 
+	log.WithField("wait_seconds", wait).Debug("acquiring power action lock for instance")
 	// Only attempt to acquire a lock on the process if this is not a termination event. We want to
 	// just allow those events to pass right through for good reason. If a server is currently trying
 	// to process a power action but has gotten stuck you still should be able to pass through the
@@ -87,33 +85,38 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 	if action != PowerActionTerminate {
 		// Determines if we should wait for the lock or not. If a value greater than 0 is passed
 		// into this function we will wait that long for a lock to be acquired.
-		if len(waitSeconds) > 0 && waitSeconds[0] != 0 {
+		if wait > 0 {
-			ctx, cancel := context.WithTimeout(context.Background(), time.Second*time.Duration(waitSeconds[0]))
+			ctx, cancel := context.WithTimeout(s.ctx, time.Second*time.Duration(wait))
 			defer cancel()
 
 			// Attempt to acquire a lock on the power action lock for up to 30 seconds. If more
 			// time than that passes an error will be propagated back up the chain and this
 			// request will be aborted.
-			if err := s.powerLock.Acquire(ctx, 1); err != nil {
+			if err := s.powerLock.TryAcquire(ctx); err != nil {
-				return errors.WithMessage(err, "could not acquire lock on power state")
+				return errors.Wrap(err, fmt.Sprintf("could not acquire lock on power action after %d seconds", wait))
 			}
 		} else {
 			// If no wait duration was provided we will attempt to immediately acquire the lock
 			// and bail out with a context deadline error if it is not acquired immediately.
-			if ok := s.powerLock.TryAcquire(1); !ok {
+			if err := s.powerLock.Acquire(); err != nil {
-				return errors.WithMessage(context.DeadlineExceeded, "could not acquire lock on power state")
+				return errors.Wrap(err, "failed to acquire exclusive lock for power actions")
 			}
 		}
 
-		// Release the lock once the process being requested has finished executing.
+		log.Info("acquired exclusive lock on power actions, processing event...")
-		defer s.powerLock.Release(1)
+		defer cleanup()
 	} else {
-		// Still try to acquire the lock if terminating, and it is available, just so that other power
+		// Still try to acquire the lock if terminating, and it is available, just so that
-		// actions are blocked until it has completed. However, if it is unavailable we won't stop
+		// other power actions are blocked until it has completed. However, if it cannot be
-		// the entire process.
+		// acquired we won't stop the entire process.
-		if ok := s.powerLock.TryAcquire(1); ok {
+		//
-			// If we managed to acquire the lock be sure to released it once this process is completed.
+		// If we did successfully acquire the lock, make sure we release it once we're done
-			defer s.powerLock.Release(1)
+		// executiong the power actions.
+		if err := s.powerLock.Acquire(); err == nil {
+			log.Info("acquired exclusive lock on power actions, processing event...")
+			defer cleanup()
+		} else {
+			log.Warn("failed to acquire exclusive lock, ignoring failure for termination event")
 		}
 	}
 
@@ -130,11 +133,11 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 
 		return s.Environment.Start(s.Context())
 	case PowerActionStop:
-		// We're specifically waiting for the process to be stopped here, otherwise the lock is released
+		fallthrough
-		// too soon, and you can rack up all sorts of issues.
-		return s.Environment.WaitForStop(10*60, true)
 	case PowerActionRestart:
-		if err := s.Environment.WaitForStop(10*60, true); err != nil {
+		// We're specifically waiting for the process to be stopped here, otherwise the lock is
+		// released too soon, and you can rack up all sorts of issues.
+		if err := s.Environment.WaitForStop(s.Context(), time.Minute*10, true); err != nil {
 			// Even timeout errors should be bubbled back up the stack. If the process didn't stop
 			// nicely, but the terminate argument was passed then the server is stopped without an
 			// error being returned.
@@ -146,6 +149,10 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 			return err
 		}
 
+		if action == PowerActionStop {
+			return nil
+		}
+
 		// Now actually try to start the process by executing the normal pre-boot logic.
 		if err := s.onBeforeStart(); err != nil {
 			return err
@@ -153,7 +160,7 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 
 		return s.Environment.Start(s.Context())
 	case PowerActionTerminate:
-		return s.Environment.Terminate(os.Kill)
+		return s.Environment.Terminate(s.Context(), os.Kill)
 	}
 
 	return errors.New("attempting to handle unknown power action")
@@ -194,15 +201,19 @@ func (s *Server) onBeforeStart() error {
 	// we don't need to actively do anything about it at this point, worse comes to worst the
 	// server starts in a weird state and the user can manually adjust.
 	s.PublishConsoleOutputFromDaemon("Updating process configuration files...")
+	s.Log().Debug("updating server configuration files...")
 	s.UpdateConfigurationFiles()
+	s.Log().Debug("updated server configuration files")
 
 	if config.Get().System.CheckPermissionsOnBoot {
 		s.PublishConsoleOutputFromDaemon("Ensuring file permissions are set correctly, this could take a few seconds...")
 		// Ensure all the server file permissions are set correctly before booting the process.
+		s.Log().Debug("chowning server root directory...")
 		if err := s.Filesystem().Chown("/"); err != nil {
 			return errors.WithMessage(err, "failed to chown root server directory during pre-boot process")
 		}
 	}
 
+	s.Log().Info("completed server preflight, starting boot process...")
 	return nil
 }

server/power_test.go

@@ -0,0 +1,22 @@
+package server
+
+import (
+	"testing"
+
+	. "github.com/franela/goblin"
+	"github.com/pterodactyl/wings/system"
+)
+
+func TestPower(t *testing.T) {
+	g := Goblin(t)
+
+	g.Describe("Server#ExecutingPowerAction", func() {
+		g.It("should return based on locker status", func() {
+			s := &Server{powerLock: system.NewLocker()}
+
+			g.Assert(s.ExecutingPowerAction()).IsFalse()
+			s.powerLock.Acquire()
+			g.Assert(s.ExecutingPowerAction()).IsTrue()
+		})
+	})
+}

server/resources.go

@@ -38,6 +38,13 @@ func (s *Server) Proc() ResourceUsage {
 	return s.resources
 }
 
+// UpdateStats updates the current stats for the server's resource usage.
+func (ru *ResourceUsage) UpdateStats(stats environment.Stats) {
+	ru.mu.Lock()
+	ru.Stats = stats
+	ru.mu.Unlock()
+}
+
 // Reset resets the usages values to zero, used when a server is stopped to ensure we don't hold
 // onto any values incorrectly.
 func (ru *ResourceUsage) Reset() {
@@ -50,7 +57,3 @@ func (ru *ResourceUsage) Reset() {
 	ru.Network.TxBytes = 0
 	ru.Network.RxBytes = 0
 }
-
-func (s *Server) emitProcUsage() {
-	s.Events().Publish(StatsEvent, s.Proc())
-}

server/server.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"os"
@@ -12,7 +11,7 @@ import (
 	"emperror.dev/errors"
 	"github.com/apex/log"
 	"github.com/creasty/defaults"
-	"golang.org/x/sync/semaphore"
+	"github.com/goccy/go-json"
 
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
@@ -31,9 +30,8 @@ type Server struct {
 	ctx       context.Context
 	ctxCancel *context.CancelFunc
 
-	emitterLock  sync.Mutex
+	emitterLock sync.Mutex
-	powerLock    *semaphore.Weighted
+	powerLock   *system.Locker
-	throttleOnce sync.Once
 
 	// Maintains the configuration for the server. This is the data that gets returned by the Panel
 	// such as build settings and container images.
@@ -65,14 +63,17 @@ type Server struct {
 	restoring    *system.AtomicBool
 
 	// The console throttler instance used to control outputs.
-	throttler *ConsoleThrottler
+	throttler    *ConsoleThrottle
+	throttleOnce sync.Once
 
 	// Tracks open websocket connections for the server.
 	wsBag       *WebsocketBag
 	wsBagLocker sync.Mutex
 
-	logSink     *sinkPool
+	sinks map[system.SinkName]*system.SinkPool
-	installSink *sinkPool
+
+	logSink     *system.SinkPool
+	installSink *system.SinkPool
 }
 
 // New returns a new server instance with a context and all of the default
@@ -86,9 +87,11 @@ func New(client remote.Client) (*Server, error) {
 		installing:   system.NewAtomicBool(false),
 		transferring: system.NewAtomicBool(false),
 		restoring:    system.NewAtomicBool(false),
-
+		powerLock:    system.NewLocker(),
-		logSink:     newSinkPool(),
+		sinks: map[system.SinkName]*system.SinkPool{
-		installSink: newSinkPool(),
+			system.LogSink:     system.NewSinkPool(),
+			system.InstallSink: system.NewSinkPool(),
+		},
 	}
 	if err := defaults.Set(&s); err != nil {
 		return nil, errors.Wrap(err, "server: could not set default values for struct")
@@ -100,6 +103,17 @@ func New(client remote.Client) (*Server, error) {
 	return &s, nil
 }
 
+// CleanupForDestroy stops all running background tasks for this server that are
+// using the context on the server struct. This will cancel any running install
+// processes for the server as well.
+func (s *Server) CleanupForDestroy() {
+	s.CtxCancel()
+	s.Events().Destroy()
+	s.DestroyAllSinks()
+	s.Websockets().CancelAll()
+	s.powerLock.Destroy()
+}
+
 // ID returns the UUID for the server instance.
 func (s *Server) ID() string {
 	return s.Config().GetUuid()
@@ -225,14 +239,6 @@ func (s *Server) ReadLogfile(len int) ([]string, error) {
 	return s.Environment.Readlog(len)
 }
 
-// Determine if the server is bootable in it's current state or not. This will not
-// indicate why a server is not bootable, only if it is.
-func (s *Server) IsBootable() bool {
-	exists, _ := s.Environment.Exists()
-
-	return exists
-}
-
 // Initializes a server instance. This will run through and ensure that the environment
 // for the server is setup, and that all of the necessary files are created.
 func (s *Server) CreateEnvironment() error {
@@ -299,7 +305,7 @@ func (s *Server) OnStateChange() {
 	// views in the Panel correctly display 0.
 	if st == environment.ProcessOfflineState {
 		s.resources.Reset()
-		s.emitProcUsage()
+		s.Events().Publish(StatsEvent, s.Proc())
 	}
 
 	// If server was in an online state, and is now in an offline state we should handle
@@ -355,11 +361,3 @@ func (s *Server) ToAPIResponse() APIResponse {
 		Configuration: *s.Config(),
 	}
 }
-
-func (s *Server) LogSink() *sinkPool {
-	return s.logSink
-}
-
-func (s *Server) InstallSink() *sinkPool {
-	return s.installSink
-}

server/sink.go

@@ -1,71 +0,0 @@
-package server
-
-import (
-	"sync"
-	"time"
-)
-
-// sinkPool represents a pool with sinks.
-type sinkPool struct {
-	mx    sync.RWMutex
-	sinks []chan []byte
-}
-
-// newSinkPool returns a new empty sinkPool.
-func newSinkPool() *sinkPool {
-	return &sinkPool{}
-}
-
-// On adds a sink on the pool.
-func (p *sinkPool) On(c chan []byte) {
-	p.mx.Lock()
-	defer p.mx.Unlock()
-
-	p.sinks = append(p.sinks, c)
-}
-
-// Off removes a sink from the pool.
-func (p *sinkPool) Off(c chan []byte) {
-	p.mx.Lock()
-	defer p.mx.Unlock()
-
-	sinks := p.sinks
-
-	for i, sink := range sinks {
-		if c != sink {
-			continue
-		}
-		copy(sinks[i:], sinks[i+1:])
-		sinks[len(sinks)-1] = nil
-		sinks = sinks[:len(sinks)-1]
-		p.sinks = sinks
-		return
-	}
-}
-
-// Destroy destroys the pool by removing and closing all sinks.
-func (p *sinkPool) Destroy() {
-	p.mx.Lock()
-	defer p.mx.Unlock()
-
-	for _, c := range p.sinks {
-		close(c)
-	}
-
-	p.sinks = nil
-}
-
-// Push pushes a message to all registered sinks.
-func (p *sinkPool) Push(v []byte) {
-	p.mx.RLock()
-	for _, c := range p.sinks {
-		// TODO: should this be done in parallel?
-		select {
-		// Send the log output to the channel
-		case c <- v:
-		// Timeout after 100 milliseconds, this will cause the write to the channel to be cancelled.
-		case <-time.After(100 * time.Millisecond):
-		}
-	}
-	p.mx.RUnlock()
-}

server/update.go

@@ -1,6 +1,8 @@
 package server
 
 import (
+	"time"
+
 	"github.com/pterodactyl/wings/environment/docker"
 
 	"github.com/pterodactyl/wings/environment"
@@ -58,7 +60,7 @@ func (s *Server) SyncWithEnvironment() {
 			s.Log().Info("server suspended with running process state, terminating now")
 
 			go func(s *Server) {
-				if err := s.Environment.WaitForStop(60, true); err != nil {
+				if err := s.Environment.WaitForStop(s.Context(), time.Minute, true); err != nil {
 					s.Log().WithField("error", err).Warn("failed to terminate server environment after suspension")
 				}
 			}(s)

sftp/handler.go

@@ -119,6 +119,9 @@ func (h *Handler) Filewrite(request *sftp.Request) (io.WriterAt, error) {
 		l.WithField("flags", request.Flags).WithField("error", err).Error("failed to open existing file on system")
 		return nil, sftp.ErrSSHFxFailure
 	}
+	// Chown may or may not have been called in the touch function, so always do
+	// it at this point to avoid the file being improperly owned.
+	_ = h.server.Filesystem().Chown(request.Filepath)
 	return f, nil
 }
 

system/locker.go

@@ -0,0 +1,85 @@
+package system
+
+import (
+	"context"
+	"sync"
+
+	"emperror.dev/errors"
+)
+
+var ErrLockerLocked = errors.Sentinel("locker: cannot acquire lock, already locked")
+
+type Locker struct {
+	mu sync.RWMutex
+	ch chan bool
+}
+
+// NewLocker returns a new Locker instance.
+func NewLocker() *Locker {
+	return &Locker{
+		ch: make(chan bool, 1),
+	}
+}
+
+// IsLocked returns the current state of the locker channel. If there is
+// currently a value in the channel, it is assumed to be locked.
+func (l *Locker) IsLocked() bool {
+	l.mu.RLock()
+	defer l.mu.RUnlock()
+	return len(l.ch) == 1
+}
+
+// Acquire will acquire the power lock if it is not currently locked. If it is
+// already locked, acquire will fail to acquire the lock, and will return false.
+func (l *Locker) Acquire() error {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	select {
+	case l.ch <- true:
+	default:
+		return ErrLockerLocked
+	}
+	return nil
+}
+
+
+// TryAcquire will attempt to acquire a power-lock until the context provided
+// is canceled.
+func (l *Locker) TryAcquire(ctx context.Context) error {
+	select {
+	case l.ch <- true:
+		return nil
+	case <-ctx.Done():
+		if err := ctx.Err(); err != nil {
+			if errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled) {
+				return ErrLockerLocked
+			}
+		}
+		return nil
+	}
+}
+
+// Release will drain the locker channel so that we can properly re-acquire it
+// at a later time. If the channel is not currently locked this function is a
+// no-op and will immediately return.
+func (l *Locker) Release() {
+	l.mu.Lock()
+	select {
+	case <-l.ch:
+	default:
+	}
+	l.mu.Unlock()
+}
+
+// Destroy cleans up the power locker by closing the channel.
+func (l *Locker) Destroy() {
+	l.mu.Lock()
+	if l.ch != nil {
+		select {
+		case <-l.ch:
+		default:
+		}
+		close(l.ch)
+	}
+	l.mu.Unlock()
+}

system/locker_test.go

@@ -0,0 +1,148 @@
+package system
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"emperror.dev/errors"
+	. "github.com/franela/goblin"
+)
+
+func TestPower(t *testing.T) {
+	g := Goblin(t)
+
+	g.Describe("Locker", func() {
+		var l *Locker
+		g.BeforeEach(func() {
+			l = NewLocker()
+		})
+
+		g.Describe("PowerLocker#IsLocked", func() {
+			g.It("should return false when the channel is empty", func() {
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(l.IsLocked()).IsFalse()
+			})
+
+			g.It("should return true when the channel is at capacity", func() {
+				l.ch <- true
+
+				g.Assert(l.IsLocked()).IsTrue()
+				<-l.ch
+				g.Assert(l.IsLocked()).IsFalse()
+
+				// We don't care what the channel value is, just that there is
+				// something in it.
+				l.ch <- false
+				g.Assert(l.IsLocked()).IsTrue()
+				g.Assert(cap(l.ch)).Equal(1)
+			})
+		})
+
+		g.Describe("PowerLocker#Acquire", func() {
+			g.It("should acquire a lock when channel is empty", func() {
+				err := l.Acquire()
+
+				g.Assert(err).IsNil()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(1)
+			})
+
+			g.It("should return an error when the channel is full", func() {
+				l.ch <- true
+
+				err := l.Acquire()
+
+				g.Assert(err).IsNotNil()
+				g.Assert(errors.Is(err, ErrLockerLocked)).IsTrue()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(1)
+			})
+		})
+
+		g.Describe("PowerLocker#TryAcquire", func() {
+			g.It("should acquire a lock when channel is empty", func() {
+				g.Timeout(time.Second)
+
+				err := l.TryAcquire(context.Background())
+
+				g.Assert(err).IsNil()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(1)
+				g.Assert(l.IsLocked()).IsTrue()
+			})
+
+			g.It("should block until context is canceled if channel is full", func() {
+				g.Timeout(time.Second)
+				ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*500)
+				defer cancel()
+
+				l.ch <- true
+				err := l.TryAcquire(ctx)
+
+				g.Assert(err).IsNotNil()
+				g.Assert(errors.Is(err, ErrLockerLocked)).IsTrue()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(1)
+				g.Assert(l.IsLocked()).IsTrue()
+			})
+
+			g.It("should block until lock can be acquired", func() {
+				g.Timeout(time.Second)
+
+				ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*200)
+				defer cancel()
+
+				l.Acquire()
+				go func() {
+					time.AfterFunc(time.Millisecond * 50, func() {
+						l.Release()
+					})
+				}()
+
+				err := l.TryAcquire(ctx)
+				g.Assert(err).IsNil()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(1)
+				g.Assert(l.IsLocked()).IsTrue()
+			})
+		})
+
+		g.Describe("PowerLocker#Release", func() {
+			g.It("should release when channel is full", func() {
+				l.Acquire()
+				g.Assert(l.IsLocked()).IsTrue()
+				l.Release()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(0)
+				g.Assert(l.IsLocked()).IsFalse()
+			})
+
+			g.It("should release when channel is empty", func() {
+				g.Assert(l.IsLocked()).IsFalse()
+				l.Release()
+				g.Assert(cap(l.ch)).Equal(1)
+				g.Assert(len(l.ch)).Equal(0)
+				g.Assert(l.IsLocked()).IsFalse()
+			})
+		})
+
+		g.Describe("PowerLocker#Destroy", func() {
+			g.It("should unlock and close the channel", func() {
+				l.Acquire()
+				g.Assert(l.IsLocked()).IsTrue()
+				l.Destroy()
+				g.Assert(l.IsLocked()).IsFalse()
+
+				defer func() {
+					r := recover()
+
+					g.Assert(r).IsNotNil()
+					g.Assert(r.(error).Error()).Equal("send on closed channel")
+				}()
+
+				l.Acquire()
+			})
+		})
+	})
+}

system/rate.go

@@ -0,0 +1,50 @@
+package system
+
+import (
+	"sync"
+	"time"
+)
+
+// Rate defines a rate limiter of n items (limit) per duration of time.
+type Rate struct {
+	mu       sync.Mutex
+	limit    uint64
+	duration time.Duration
+	count    uint64
+	last     time.Time
+}
+
+func NewRate(limit uint64, duration time.Duration) *Rate {
+	return &Rate{
+		limit:    limit,
+		duration: duration,
+		last:     time.Now(),
+	}
+}
+
+// Try returns true if under the rate limit defined, or false if the rate limit
+// has been exceeded for the current duration.
+func (r *Rate) Try() bool {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	now := time.Now()
+	// If it has been more than the duration, reset the timer and count.
+	if now.Sub(r.last) > r.duration {
+		r.count = 0
+		r.last = now
+	}
+	if (r.count + 1) > r.limit {
+		return false
+	}
+	// Hit this once, and return.
+	r.count = r.count + 1
+	return true
+}
+
+// Reset resets the internal state of the rate limiter back to zero.
+func (r *Rate) Reset() {
+	r.mu.Lock()
+    r.count = 0
+    r.last = time.Now()
+	r.mu.Unlock()
+}

system/rate_test.go

@@ -0,0 +1,67 @@
+package system
+
+import (
+	"testing"
+	"time"
+
+	. "github.com/franela/goblin"
+)
+
+func TestRate(t *testing.T) {
+	g := Goblin(t)
+
+	g.Describe("Rate", func() {
+		g.It("properly rate limits a bucket", func() {
+			r := NewRate(10, time.Millisecond*100)
+
+			for i := 0; i < 100; i++ {
+				ok := r.Try()
+				if i < 10 && !ok {
+					g.Failf("should not have allowed take on try %d", i)
+				} else if i >= 10 && ok {
+					g.Failf("should have blocked take on try %d", i)
+				}
+			}
+		})
+
+		g.It("handles rate limiting in chunks", func() {
+			var out []int
+			r := NewRate(12, time.Millisecond*10)
+
+			for i := 0; i < 100; i++ {
+				if i%20 == 0 {
+					// Give it time to recover.
+					time.Sleep(time.Millisecond * 10)
+				}
+				if r.Try() {
+					out = append(out, i)
+				}
+			}
+
+			g.Assert(len(out)).Equal(60)
+			g.Assert(out[0]).Equal(0)
+			g.Assert(out[12]).Equal(20)
+			g.Assert(out[len(out)-1]).Equal(91)
+		})
+
+		g.It("resets back to zero when called", func() {
+			r := NewRate(10, time.Second)
+			for i := 0; i < 100; i++ {
+				if i % 10 == 0 {
+					r.Reset()
+				}
+				g.Assert(r.Try()).IsTrue()
+			}
+			g.Assert(r.Try()).IsFalse("final attempt should not allow taking")
+		})
+	})
+}
+
+func BenchmarkRate_Try(b *testing.B) {
+	r := NewRate(10, time.Millisecond*100)
+
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		r.Try()
+	}
+}

system/sink_pool.go

@@ -0,0 +1,121 @@
+package system
+
+import (
+	"sync"
+	"time"
+)
+
+// SinkName represents one of the registered sinks for a server.
+type SinkName string
+
+const (
+	// LogSink handles console output for game servers, including messages being
+	// sent via Wings to the console instance.
+	LogSink SinkName = "log"
+	// InstallSink handles installation output for a server.
+	InstallSink SinkName = "install"
+)
+
+// SinkPool represents a pool with sinks.
+type SinkPool struct {
+	mu    sync.RWMutex
+	sinks []chan []byte
+}
+
+// NewSinkPool returns a new empty SinkPool. A sink pool generally lives with a
+// server instance for it's full lifetime.
+func NewSinkPool() *SinkPool {
+	return &SinkPool{}
+}
+
+// On adds a channel to the sink pool instance.
+func (p *SinkPool) On(c chan []byte) {
+	p.mu.Lock()
+	p.sinks = append(p.sinks, c)
+	p.mu.Unlock()
+}
+
+// Off removes a given channel from the sink pool. If no matching sink is found
+// this function is a no-op. If a matching channel is found, it will be removed.
+func (p *SinkPool) Off(c chan []byte) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	sinks := p.sinks
+	for i, sink := range sinks {
+		if c != sink {
+			continue
+		}
+
+		// We need to maintain the order of the sinks in the slice we're tracking,
+		// so shift everything to the left, rather than changing the order of the
+		// elements.
+		copy(sinks[i:], sinks[i+1:])
+		sinks[len(sinks)-1] = nil
+		sinks = sinks[:len(sinks)-1]
+		p.sinks = sinks
+
+		// Avoid a panic if the sink channel is nil at this point.
+		if c != nil {
+			close(c)
+		}
+
+		return
+	}
+}
+
+// Destroy destroys the pool by removing and closing all sinks and destroying
+// all of the channels that are present.
+func (p *SinkPool) Destroy() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	for _, c := range p.sinks {
+		if c != nil {
+			close(c)
+		}
+	}
+
+	p.sinks = nil
+}
+
+// Push sends a given message to each of the channels registered in the pool.
+// This will use a Ring Buffer channel in order to avoid blocking the channel
+// sends, and attempt to push though the most recent messages in the queue in
+// favor of the oldest messages.
+//
+// If the channel becomes full and isn't being drained fast enough, this
+// function will remove the oldest message in the channel, and then push the
+// message that it got onto the end, effectively making the channel a rolling
+// buffer.
+//
+// There is a potential for data to be lost when passing it through this
+// function, but only in instances where the channel buffer is full and the
+// channel is not drained fast enough, in which case dropping messages is most
+// likely the best option anyways. This uses waitgroups to allow every channel
+// to attempt its send concurrently thus making the total blocking time of this
+// function "O(1)" instead of "O(n)".
+func (p *SinkPool) Push(data []byte) {
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+	var wg sync.WaitGroup
+	wg.Add(len(p.sinks))
+	for _, c := range p.sinks {
+		go func(c chan []byte) {
+			defer wg.Done()
+			select {
+			case c <- data:
+			case <-time.After(time.Millisecond * 10):
+				// If there is nothing in the channel to read, but we also cannot write
+				// to the channel, just skip over sending data. If we don't do this you'll
+				// end up blocking the application on the channel read below.
+				if len(c) == 0 {
+					break
+				}
+				<-c
+				c <- data
+			}
+		}(c)
+	}
+	wg.Wait()
+}

system/sink_pool_test.go

@@ -0,0 +1,236 @@
+package system
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	. "github.com/franela/goblin"
+)
+
+func MutexLocked(m *sync.RWMutex) bool {
+	v := reflect.ValueOf(m).Elem()
+
+	state := v.FieldByName("w").FieldByName("state")
+
+	return state.Int()&1 == 1 || v.FieldByName("readerCount").Int() > 0
+}
+
+func TestSink(t *testing.T) {
+	g := Goblin(t)
+
+	g.Describe("SinkPool#On", func() {
+		g.It("pushes additional channels to a sink", func() {
+			pool := &SinkPool{}
+
+			g.Assert(pool.sinks).IsZero()
+
+			c1 := make(chan []byte, 1)
+			pool.On(c1)
+
+			g.Assert(len(pool.sinks)).Equal(1)
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+	})
+
+	g.Describe("SinkPool#Off", func() {
+		var pool *SinkPool
+		g.BeforeEach(func() {
+			pool = &SinkPool{}
+		})
+
+		g.It("works when no sinks are registered", func() {
+			ch := make(chan []byte, 1)
+
+			g.Assert(pool.sinks).IsZero()
+			pool.Off(ch)
+
+			g.Assert(pool.sinks).IsZero()
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+
+		g.It("does not remove any sinks when the channel does not match", func() {
+			ch := make(chan []byte, 1)
+			ch2 := make(chan []byte, 1)
+
+			pool.On(ch)
+			g.Assert(len(pool.sinks)).Equal(1)
+
+			pool.Off(ch2)
+			g.Assert(len(pool.sinks)).Equal(1)
+			g.Assert(pool.sinks[0]).Equal(ch)
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+
+		g.It("removes a channel and maintains the order", func() {
+			channels := make([]chan []byte, 8)
+			for i := 0; i < len(channels); i++ {
+				channels[i] = make(chan []byte, 1)
+				pool.On(channels[i])
+			}
+
+			g.Assert(len(pool.sinks)).Equal(8)
+
+			pool.Off(channels[2])
+			g.Assert(len(pool.sinks)).Equal(7)
+			g.Assert(pool.sinks[1]).Equal(channels[1])
+			g.Assert(pool.sinks[2]).Equal(channels[3])
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+
+		g.It("does not panic if a nil channel is provided", func() {
+			ch := make([]chan []byte, 1)
+
+			defer func() {
+				if r := recover(); r != nil {
+					g.Fail("removing a nil channel should not cause a panic")
+				}
+			}()
+
+			pool.On(ch[0])
+			pool.Off(ch[0])
+
+			g.Assert(len(pool.sinks)).Equal(0)
+		})
+	})
+
+	g.Describe("SinkPool#Push", func() {
+		var pool *SinkPool
+		g.BeforeEach(func() {
+			pool = &SinkPool{}
+		})
+
+		g.It("works when no sinks are registered", func() {
+			g.Assert(len(pool.sinks)).IsZero()
+			pool.Push([]byte("test"))
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+
+		g.It("sends data to every registered sink", func() {
+			ch1 := make(chan []byte, 1)
+			ch2 := make(chan []byte, 1)
+
+			pool.On(ch1)
+			pool.On(ch2)
+
+			g.Assert(len(pool.sinks)).Equal(2)
+			b := []byte("test")
+			pool.Push(b)
+
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+			g.Assert(<-ch1).Equal(b)
+			g.Assert(<-ch2).Equal(b)
+			g.Assert(len(pool.sinks)).Equal(2)
+		})
+
+		g.It("uses a ring-buffer to avoid blocking when the channel is full", func() {
+			ch1 := make(chan []byte, 1)
+			ch2 := make(chan []byte, 2)
+			ch3 := make(chan []byte)
+
+			// ch1 and ch2 are now full, and would block if the code doesn't account
+			// for a full buffer.
+			ch1 <- []byte("pre-test")
+			ch2 <- []byte("pre-test")
+			ch2 <- []byte("pre-test 2")
+
+			pool.On(ch1)
+			pool.On(ch2)
+			pool.On(ch3)
+
+			pool.Push([]byte("testing"))
+			time.Sleep(time.Millisecond * 20)
+
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+			// We expect that value previously in the channel to have been dumped
+			// and therefore only the value we pushed will be present. For ch2 we
+			// expect only the first message was dropped, and the second one is now
+			// the first in the out queue.
+			g.Assert(<-ch1).Equal([]byte("testing"))
+			g.Assert(<-ch2).Equal([]byte("pre-test 2"))
+			g.Assert(<-ch2).Equal([]byte("testing"))
+
+			// Because nothing in this test was listening for ch3, it would have
+			// blocked for the 10ms duration, and then been skipped over entirely
+			// because it had no length to try and push onto.
+			g.Assert(len(ch3)).Equal(0)
+
+			// Now, push again and expect similar results.
+			pool.Push([]byte("testing 2"))
+			time.Sleep(time.Millisecond * 20)
+
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+			g.Assert(<-ch1).Equal([]byte("testing 2"))
+			g.Assert(<-ch2).Equal([]byte("testing 2"))
+		})
+
+		g.It("can handle concurrent pushes FIFO", func() {
+			ch := make(chan []byte, 4)
+
+			pool.On(ch)
+			pool.On(make(chan []byte))
+
+			for i := 0; i < 100; i++ {
+				pool.Push([]byte(fmt.Sprintf("iteration %d", i)))
+			}
+
+			time.Sleep(time.Millisecond * 20)
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+			g.Assert(len(ch)).Equal(4)
+
+			g.Timeout(time.Millisecond * 500)
+			g.Assert(<-ch).Equal([]byte("iteration 96"))
+			g.Assert(<-ch).Equal([]byte("iteration 97"))
+			g.Assert(<-ch).Equal([]byte("iteration 98"))
+			g.Assert(<-ch).Equal([]byte("iteration 99"))
+			g.Assert(len(ch)).Equal(0)
+		})
+	})
+
+	g.Describe("SinkPool#Destroy", func() {
+		var pool *SinkPool
+		g.BeforeEach(func() {
+			pool = &SinkPool{}
+		})
+
+		g.It("works if no sinks are registered", func() {
+			pool.Destroy()
+
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+
+		g.It("closes all channels fully", func() {
+			ch1 := make(chan []byte, 1)
+			ch2 := make(chan []byte, 1)
+
+			pool.On(ch1)
+			pool.On(ch2)
+
+			g.Assert(len(pool.sinks)).Equal(2)
+			pool.Destroy()
+			g.Assert(pool.sinks).IsZero()
+
+			defer func() {
+				r := recover()
+
+				g.Assert(r).IsNotNil()
+				g.Assert(r.(error).Error()).Equal("send on closed channel")
+			}()
+
+			ch1 <- []byte("test")
+		})
+
+		g.It("works when a sink channel is nil", func() {
+			ch := make([]chan []byte, 2)
+
+			pool.On(ch[0])
+			pool.On(ch[1])
+
+			pool.Destroy()
+
+			g.Assert(MutexLocked(&pool.mu)).IsFalse()
+		})
+	})
+}

system/utils.go

@@ -3,15 +3,13 @@ package system
 import (
 	"bufio"
 	"bytes"
-	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"strconv"
 	"sync"
-	"time"
 
 	"emperror.dev/errors"
+	"github.com/goccy/go-json"
 )
 
 var (
@@ -19,6 +17,11 @@ var (
 	crr = []byte("\r\n")
 )
 
+// The maximum size of the buffer used to send output over the console to
+// clients. Once this length is reached, the line will be truncated and sent
+// as is.
+var maxBufferSize = 64 * 1024
+
 // FirstNotEmpty returns the first string passed in that is not an empty value.
 func FirstNotEmpty(v ...string) string {
 	for _, val := range v {
@@ -37,12 +40,22 @@ func MustInt(v string) int {
 	return i
 }
 
+// ScanReader reads up to 64KB of line from the reader and emits that value
+// over the websocket. If a line exceeds that size, it is truncated and only that
+// amount is sent over.
 func ScanReader(r io.Reader, callback func(line []byte)) error {
-	br := bufio.NewReader(r)
+	// Based on benchmarking this seems to be the best size for the reader buffer
+	// to maintain fast enough workflows without hammering the CPU for allocations.
+	//
+	// Additionally, most games are outputting a high-frequency of smaller lines,
+	// rather than a bunch of massive lines. This allocation amount is the total
+	// number of bytes being output for each call to ReadLine() before it moves on
+	// to the next data pull.
+	br := bufio.NewReaderSize(r, 256)
 	// Avoid constantly re-allocating memory when we're flooding lines through this
 	// function by using the same buffer for the duration of the call and just truncating
 	// the value back to 0 every loop.
-	buf := &bytes.Buffer{}
+	var buf bytes.Buffer
 	for {
 		buf.Reset()
 		var err error
@@ -52,30 +65,54 @@ func ScanReader(r io.Reader, callback func(line []byte)) error {
 		for {
 			// Read the line and write it to the buffer.
 			line, isPrefix, err = br.ReadLine()
+
 			// Certain games like Minecraft output absolutely random carriage returns in the output seemingly
 			// in line with that it thinks is the terminal size. Those returns break a lot of output handling,
 			// so we'll just replace them with proper new-lines and then split it later and send each line as
 			// its own event in the response.
-			buf.Write(bytes.Replace(line, cr, crr, -1))
+			line = bytes.Replace(line, cr, crr, -1)
-			// Finish this loop and begin outputting the line if there is no prefix (the line fit into
+			ns := buf.Len() + len(line)
-			// the default buffer), or if we hit the end of the line.
+
+			// If the length of the line value and the current value in the buffer will
+			// exceed the maximum buffer size, chop it down to hit the maximum size and
+			// then send that data over the socket before ending this loop.
+			//
+			// This ensures that we send as much data as possible, without allowing very
+			// long lines to grow the buffer size excessively and potentially DOS the Wings
+			// instance. If the line is not too long, just store the whole value into the
+			// buffer. This is kind of a re-implementation of the bufio.Scanner.Scan() logic
+			// without triggering an error when you exceed this buffer size.
+			if ns > maxBufferSize {
+				buf.Write(line[:len(line)-(ns-maxBufferSize)])
+				break
+			} else {
+				buf.Write(line)
+			}
+			// If we encountered an error with something in ReadLine that was not an
+			// EOF just abort the entire process here.
+			if err != nil && err != io.EOF {
+				return err
+			}
+			// Finish this loop and begin outputting the line if there is no prefix
+			// (the line fit into the default buffer), or if we hit the end of the line.
 			if !isPrefix || err == io.EOF {
 				break
 			}
-			// If we encountered an error with something in ReadLine that was not an EOF just abort
-			// the entire process here.
-			if err != nil {
-				return err
-			}
 		}
-		// Publish the line for this loop. Break on new-line characters so every line is sent as a single
+
-		// output event, otherwise you get funky handling in the browser console.
+		// Send the full buffer length over to the event handler to be emitted in
-		s := bufio.NewScanner(buf)
+		// the websocket. The front-end can handle the linebreaks in the middle of
-		for s.Scan() {
+		// the output, it simply expects that the end of the event emit is a newline.
-			callback(s.Bytes())
+		if buf.Len() > 0 {
+			// You need to make a copy of the buffer here because the callback will encounter
+			// a race condition since "buf.Bytes()" is going to be by-reference if passed directly.
+			c := make([]byte, buf.Len())
+			copy(c, buf.Bytes())
+			callback(c)
 		}
-		// If the error we got previously that lead to the line being output is an io.EOF we want to
+
-		// exit the entire looping process.
+		// If the error we got previously that lead to the line being output is
+		// an io.EOF we want to exit the entire looping process.
 		if err == io.EOF {
 			break
 		}
@@ -83,22 +120,6 @@ func ScanReader(r io.Reader, callback func(line []byte)) error {
 	return nil
 }
 
-// Runs a given work function every "d" duration until the provided context is canceled.
-func Every(ctx context.Context, d time.Duration, work func(t time.Time)) {
-	ticker := time.NewTicker(d)
-	go func() {
-		for {
-			select {
-			case <-ctx.Done():
-				ticker.Stop()
-				return
-			case t := <-ticker.C:
-				work(t)
-			}
-		}
-	}()
-}
-
 func FormatBytes(b int64) string {
 	if b < 1024 {
 		return fmt.Sprintf("%d B", b)
@@ -126,9 +147,9 @@ func (ab *AtomicBool) Store(v bool) {
 	ab.mu.Unlock()
 }
 
-// Stores the value "v" if the current value stored in the AtomicBool is the opposite
+// SwapIf stores the value "v" if the current value stored in the AtomicBool is
-// boolean value. If successfully swapped, the response is "true", otherwise "false"
+// the opposite boolean value. If successfully swapped, the response is "true",
-// is returned.
+// otherwise "false" is returned.
 func (ab *AtomicBool) SwapIf(v bool) bool {
 	ab.mu.Lock()
 	defer ab.mu.Unlock()

system/utils_test.go

@@ -0,0 +1,135 @@
+package system
+
+import (
+	"math/rand"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	. "github.com/franela/goblin"
+	"github.com/goccy/go-json"
+)
+
+func Test_Utils(t *testing.T) {
+	g := Goblin(t)
+
+	g.Describe("ScanReader", func() {
+		g.BeforeEach(func() {
+			maxBufferSize = 10
+		})
+
+		g.It("should truncate and return long lines", func() {
+			reader := strings.NewReader("hello world this is a long line\nof text that should be truncated\nnot here\nbut definitely on this line")
+
+			var lines []string
+			err := ScanReader(reader, func(line []byte) {
+				lines = append(lines, string(line))
+			})
+
+			g.Assert(err).IsNil()
+			g.Assert(lines).Equal([]string{"hello worl", "of text th", "not here", "but defini"})
+		})
+
+		g.It("should replace cariage returns with newlines", func() {
+			reader := strings.NewReader("test\rstring\r\nanother\rline\nhodor\r\r\rheld the door\nmaterial gourl\n")
+			var lines []string
+			err := ScanReader(reader, func(line []byte) {
+				lines = append(lines, string(line))
+			})
+
+			g.Assert(err).IsNil()
+			g.Assert(lines).Equal([]string{"test\rstrin", "another\rli", "hodor\r\r\rhe", "material g"})
+		})
+	})
+
+	g.Describe("AtomicBool", func() {
+		var b *AtomicBool
+		g.BeforeEach(func() {
+			b = NewAtomicBool(false)
+		})
+
+		g.It("initalizes with the provided start value", func() {
+			b = NewAtomicBool(true)
+			g.Assert(b.Load()).IsTrue()
+
+			b = NewAtomicBool(false)
+			g.Assert(b.Load()).IsFalse()
+		})
+
+		g.Describe("AtomicBool#Store", func() {
+			g.It("stores the provided value", func() {
+				g.Assert(b.Load()).IsFalse()
+				b.Store(true)
+				g.Assert(b.Load()).IsTrue()
+			})
+
+			// This test makes no assertions, it just expects to not hit a race condition
+			// by having multiple things writing at the same time.
+			g.It("handles contention from multiple routines", func() {
+				var wg sync.WaitGroup
+
+				wg.Add(100)
+				for i := 0; i < 100; i++ {
+					go func(i int) {
+						b.Store(i%2 == 0)
+						wg.Done()
+					}(i)
+				}
+				wg.Wait()
+			})
+		})
+
+		g.Describe("AtomicBool#SwapIf", func() {
+			g.It("swaps the value out if different than what is stored", func() {
+				o := b.SwapIf(false)
+				g.Assert(o).IsFalse()
+				g.Assert(b.Load()).IsFalse()
+
+				o = b.SwapIf(true)
+				g.Assert(o).IsTrue()
+				g.Assert(b.Load()).IsTrue()
+
+				o = b.SwapIf(true)
+				g.Assert(o).IsFalse()
+				g.Assert(b.Load()).IsTrue()
+
+				o = b.SwapIf(false)
+				g.Assert(o).IsTrue()
+				g.Assert(b.Load()).IsFalse()
+			})
+		})
+
+		g.Describe("can be marshaled with JSON", func() {
+			type testStruct struct {
+				Value AtomicBool `json:"value"`
+			}
+
+			var o testStruct
+			err := json.Unmarshal([]byte(`{"value":true}`), &o)
+
+			g.Assert(err).IsNil()
+			g.Assert(o.Value.Load()).IsTrue()
+
+			b, err2 := json.Marshal(&o)
+			g.Assert(err2).IsNil()
+			g.Assert(b).Equal([]byte(`{"value":true}`))
+		})
+	})
+}
+
+func Benchmark_ScanReader(b *testing.B) {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	var str string
+	for i := 0; i < 10; i++ {
+		str += strings.Repeat("hello \rworld", r.Intn(2000)) + "\n"
+	}
+	reader := strings.NewReader(str)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = ScanReader(reader, func(line []byte) {
+			// no op
+		})
+	}
+}