Merge develop into feature/file-uploads

.github/workflows/release.yml

@@ -23,7 +23,7 @@ jobs:
         run: go test ./...
       
       - name: Compress binary and make it executable
-        run: upx build/wings_linux_amd64 && chmod +x build/wings_linux_amd64
+        run: upx --brute build/wings_linux_amd64 && chmod +x build/wings_linux_amd64
 
       - name: Extract changelog
         env:
@@ -32,7 +32,6 @@ jobs:
           sed -n "/^## ${REF:10}/,/^## /{/^## /b;p}" CHANGELOG.md > ./RELEASE_CHANGELOG
           echo ::set-output name=version_name::`sed -nr "s/^## (${REF:10} .*)$/\1/p" CHANGELOG.md`
 
-
       - name: Create checksum and add to changelog
         run: |
           SUM=`cd build && sha256sum wings_linux_amd64`
@@ -48,8 +47,8 @@ jobs:
           git config --local user.name "Pterodactyl CI"
           git checkout -b $BRANCH
           git push -u origin $BRANCH
-          sed -i "s/	Version = \".*\"/	Version = \"${REF:11}\"/" config/app.php
+          sed -i "s/	Version = \".*\"/	Version = \"${REF:11}\"/" system/const.go
-          git add config/app.php
+          git add system/const.go
           git commit -m "bump version for release"
           git push
 

cmd/root.go

@@ -169,7 +169,7 @@ func rootCmdRun(*cobra.Command, []string) {
 
 	// Just for some nice log output.
 	for _, s := range server.GetServers().All() {
-		log.WithField("server", s.Uuid).Info("loaded configuration for server")
+		log.WithField("server", s.Id()).Info("loaded configuration for server")
 	}
 
 	// Create a new WaitGroup that limits us to 4 servers being bootstrapped at a time
@@ -181,17 +181,13 @@ func rootCmdRun(*cobra.Command, []string) {
 		wg.Add()
 
 		go func(s *server.Server) {
-			// Required for tracing purposes.
+			defer wg.Done()
-			var err error
 
-			defer func() {
+			s.Log().Info("ensuring server environment exists")
-				s.Log().Trace("ensuring server environment exists").Stop(&err)
-				wg.Done()
-			}()
 
 			// Create a server environment if none exists currently. This allows us to recover from Docker
 			// being reinstalled on the host system for example.
-			if err = s.Environment.Create(); err != nil {
+			if err := s.Environment.Create(); err != nil {
 				s.Log().WithField("error", err).Error("failed to process environment")
 			}
 

go.mod

@@ -31,6 +31,7 @@ require (
 	github.com/docker/go-units v0.3.3 // indirect
 	github.com/fatih/color v1.9.0
 	github.com/gabriel-vasile/mimetype v0.1.4
+	github.com/gammazero/workerpool v0.0.0-20200608033439-1a5ca90a5753
 	github.com/gbrlsnchs/jwt/v3 v3.0.0-rc.0
 	github.com/gin-gonic/gin v1.6.3
 	github.com/golang/protobuf v1.3.5 // indirect

go.sum

@@ -79,6 +79,10 @@ github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/gabriel-vasile/mimetype v0.1.4 h1:5mcsq3+DXypREUkW+1juhjeKmE/XnWgs+paHMJn7lf8=
 github.com/gabriel-vasile/mimetype v0.1.4/go.mod h1:kMJbg3SlWZCsj4R73F1WDzbT9AyGCOVmUtIxxwO5pmI=
+github.com/gammazero/deque v0.0.0-20200227231300-1e9af0e52b46 h1:iX4+rD9Fjdx8SkmSO/O5WAIX/j79ll3kuqv5VdYt9J8=
+github.com/gammazero/deque v0.0.0-20200227231300-1e9af0e52b46/go.mod h1:D90+MBHVc9Sk1lJAbEVgws0eYEurY4mv2TDso3Nxh3w=
+github.com/gammazero/workerpool v0.0.0-20200608033439-1a5ca90a5753 h1:oSQ61LxZkz3Z4La0O5cbyVDvLWEfbNgiD43cSPdjPQQ=
+github.com/gammazero/workerpool v0.0.0-20200608033439-1a5ca90a5753/go.mod h1:/XWO2YAUUpPi3smDlFBl0vpX0JHwUomDM/oRMwRmnSs=
 github.com/gbrlsnchs/jwt/v3 v3.0.0-rc.0 h1:7KeiSrO5puFH1+vdAdbpiie2TrNnkvFc/eOQzT60Z2k=
 github.com/gbrlsnchs/jwt/v3 v3.0.0-rc.0/go.mod h1:D1+3UtCYAJ1os1PI+zhTVEj6Tb+IHJvXjXKz83OstmM=
 github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=

installer/installer.go

@@ -29,12 +29,10 @@ func New(data []byte) (*Installer, error) {
 		return nil, NewValidationError("service egg provided was not in a valid format")
 	}
 
-	s := &server.Server{
+	cfg := &server.Configuration{
 		Uuid:       getString(data, "uuid"),
 		Suspended:  false,
-		State:      server.ProcessOfflineState,
 		Invocation: getString(data, "invocation"),
-		EnvVars:    make(server.EnvironmentVariables),
 		Build: server.BuildSettings{
 			MemoryLimit: getInt(data, "build", "memory"),
 			Swap:        getInt(data, "build", "swap"),
@@ -43,20 +41,18 @@ func New(data []byte) (*Installer, error) {
 			DiskSpace:   getInt(data, "build", "disk"),
 			Threads:     getString(data, "build", "threads"),
 		},
-		Allocations: server.Allocations{
+		CrashDetectionEnabled: true,
-			Mappings: make(map[string][]int),
-		},
 	}
 
-	s.Allocations.DefaultMapping.Ip = getString(data, "allocations", "default", "ip")
+	cfg.Allocations.DefaultMapping.Ip = getString(data, "allocations", "default", "ip")
-	s.Allocations.DefaultMapping.Port = int(getInt(data, "allocations", "default", "port"))
+	cfg.Allocations.DefaultMapping.Port = int(getInt(data, "allocations", "default", "port"))
 
 	// Unmarshal the environment variables from the request into the server struct.
 	if b, _, _, err := jsonparser.Get(data, "environment"); err != nil {
 		return nil, errors.WithStack(err)
 	} else {
-		s.EnvVars = make(server.EnvironmentVariables)
+		cfg.EnvVars = make(server.EnvironmentVariables)
-		if err := json.Unmarshal(b, &s.EnvVars); err != nil {
+		if err := json.Unmarshal(b, &cfg.EnvVars); err != nil {
 			return nil, errors.WithStack(err)
 		}
 	}
@@ -65,15 +61,15 @@ func New(data []byte) (*Installer, error) {
 	if b, _, _, err := jsonparser.Get(data, "allocations", "mappings"); err != nil {
 		return nil, errors.WithStack(err)
 	} else {
-		s.Allocations.Mappings = make(map[string][]int)
+		cfg.Allocations.Mappings = make(map[string][]int)
-		if err := json.Unmarshal(b, &s.Allocations.Mappings); err != nil {
+		if err := json.Unmarshal(b, &cfg.Allocations.Mappings); err != nil {
 			return nil, errors.WithStack(err)
 		}
 	}
 
-	s.Container.Image = getString(data, "container", "image")
+	cfg.Container.Image = getString(data, "container", "image")
 
-	c, rerr, err := api.NewRequester().GetServerConfiguration(s.Uuid)
+	c, rerr, err := api.NewRequester().GetServerConfiguration(cfg.Uuid)
 	if err != nil || rerr != nil {
 		if err != nil {
 			return nil, errors.WithStack(err)
@@ -82,21 +78,18 @@ func New(data []byte) (*Installer, error) {
 		return nil, errors.New(rerr.String())
 	}
 
-	// Destroy the temporary server instance.
-	s = nil
-
 	// Create a new server instance using the configuration we wrote to the disk
 	// so that everything gets instantiated correctly on the struct.
-	s2, err := server.FromConfiguration(c)
+	s, err := server.FromConfiguration(c)
 
 	return &Installer{
-		server: s2,
+		server: s,
 	}, err
 }
 
 // Returns the UUID associated with this installer instance.
 func (i *Installer) Uuid() string {
-	return i.server.Uuid
+	return i.server.Id()
 }
 
 // Return the server instance.

loggers/cli/cli.go

@@ -81,7 +81,7 @@ func (h *Handler) HandleLog(e *log.Entry) error {
 }
 
 func getErrorStack(err error, i bool) errors.StackTrace {
-	e, ok := errors.Cause(err).(tracer)
+	e, ok := err.(tracer)
 	if !ok {
 		if i {
 			// Just abort out of this and return a stacktrace leading up to this point. It isn't perfect
@@ -89,7 +89,7 @@ func getErrorStack(err error, i bool) errors.StackTrace {
 			return errors.Wrap(err, "failed to generate stacktrace for caught error").(tracer).StackTrace()
 		}
 
-		return getErrorStack(errors.New(err.Error()), true)
+		return getErrorStack(errors.Wrap(err, err.Error()), true)
 	}
 
 	st := e.StackTrace()

router/error.go

@@ -33,7 +33,7 @@ func TrackedError(err error) *RequestError {
 // generated this server for the purposes of logging.
 func TrackedServerError(err error, s *server.Server) *RequestError {
 	return &RequestError{
-		Err:     err,
+		Err:     errors.WithStack(err),
 		Uuid:    uuid.Must(uuid.NewRandom()).String(),
 		Message: "",
 		server:  s,

router/middleware.go

@@ -48,7 +48,7 @@ func AuthorizationMiddleware(c *gin.Context) {
 // Helper function to fetch a server out of the servers collection stored in memory.
 func GetServer(uuid string) *server.Server {
 	return server.GetServers().Find(func(s *server.Server) bool {
-		return uuid == s.Uuid
+		return uuid == s.Id()
 	})
 }
 

router/router.go

@@ -85,6 +85,7 @@ func Configure() *gin.Engine {
 			files.POST("/create-directory", postServerCreateDirectory)
 			files.POST("/delete", postServerDeleteFiles)
 			files.POST("/compress", postServerCompressFiles)
+			files.POST("/decompress", postServerDecompressFiles)
 		}
 
 		backup := server.Group("/backup")

router/router_server.go

@@ -13,7 +13,9 @@ import (
 
 // Returns a single server from the collection of servers.
 func getServer(c *gin.Context) {
-	c.JSON(http.StatusOK, GetServer(c.Param("server")))
+	s := GetServer(c.Param("server"))
+
+	c.JSON(http.StatusOK, s.Proc())
 }
 
 // Returns the logs for a given server instance.
@@ -64,7 +66,7 @@ func postServerPower(c *gin.Context) {
 	//
 	// We don't really care about any of the other actions at this point, they'll all result
 	// in the process being stopped, which should have happened anyways if the server is suspended.
-	if (data.Action == "start" || data.Action == "restart") && s.Suspended {
+	if (data.Action == "start" || data.Action == "restart") && s.IsSuspended() {
 		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
 			"error": "Cannot start or restart a server that is suspended.",
 		})
@@ -162,7 +164,7 @@ func deleteServer(c *gin.Context) {
 
 	// Immediately suspend the server to prevent a user from attempting
 	// to start it while this process is running.
-	s.Suspended = true
+	s.Config().SetSuspended(true)
 
 	// If the server is currently installing, abort it.
 	if s.IsInstalling() {
@@ -200,9 +202,9 @@ func deleteServer(c *gin.Context) {
 		}
 	}(s.Filesystem.Path())
 
-	var uuid = s.Uuid
+	var uuid = s.Id()
 	server.GetServers().Remove(func(s2 *server.Server) bool {
-		return s2.Uuid == uuid
+		return s2.Id() == uuid
 	})
 
 	// Deallocate the reference to this server.

router/router_server_files.go

@@ -3,7 +3,6 @@ package router
 import (
 	"bufio"
 	"context"
-	"github.com/apex/log"
 	"github.com/gin-gonic/gin"
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/router/tokens"
@@ -83,6 +82,13 @@ func getServerListDirectory(c *gin.Context) {
 
 	stats, err := s.Filesystem.ListDirectory(d)
 	if err != nil {
+		if err.Error() == "readdirent: not a directory" {
+			c.AbortWithStatusJSON(http.StatusNotFound, gin.H{
+				"error": "The requested directory does not exist.",
+			})
+			return
+		}
+
 		TrackedServerError(err, s).AbortWithServerError(c)
 		return
 	}
@@ -175,7 +181,7 @@ func postServerDeleteFiles(c *gin.Context) {
 
 	if len(data.Files) == 0 {
 		c.AbortWithStatusJSON(http.StatusUnprocessableEntity, gin.H{
-			"error": "No files were specified for deletion.",
+			"error": "No files were specififed for deletion.",
 		})
 		return
 	}
@@ -283,6 +289,39 @@ func postServerCompressFiles(c *gin.Context) {
 	})
 }
 
+func postServerDecompressFiles(c *gin.Context) {
+	s := GetServer(c.Param("server"))
+
+	var data struct {
+		RootPath string `json:"root"`
+		File     string `json:"file"`
+	}
+
+	if err := c.BindJSON(&data); err != nil {
+		return
+	}
+
+	hasSpace, err := s.Filesystem.SpaceAvailableForDecompression(data.RootPath, data.File)
+	if err != nil {
+		TrackedServerError(err, s).AbortWithServerError(c)
+		return
+	}
+
+	if !hasSpace {
+		c.AbortWithStatusJSON(http.StatusConflict, gin.H{
+			"error": "This server does not have enough available disk space to decompress this archive.",
+		})
+		return
+	}
+
+	if err := s.Filesystem.DecompressFile(data.RootPath, data.File); err != nil {
+		TrackedServerError(err, s).AbortWithServerError(c)
+		return
+	}
+
+	c.Status(http.StatusNoContent)
+}
+
 func postServerUploadFiles(c *gin.Context) {
 	token := tokens.UploadPayload{}
 	if err := tokens.ParseToken([]byte(c.Query("token")), &token); err != nil {
@@ -313,10 +352,6 @@ func postServerUploadFiles(c *gin.Context) {
 		return
 	}
 
-	for i := range form.File {
-		log.Debug(i)
-	}
-
 	headers, ok := form.File["files"]
 	if !ok {
 		c.AbortWithStatusJSON(http.StatusNotModified, gin.H{
@@ -335,7 +370,6 @@ func postServerUploadFiles(c *gin.Context) {
 			c.AbortWithError(http.StatusInternalServerError, err)
 			return
 		}
-		log.Debug(p)
 
 		// We run this in a different method so I can use defer without any of
 		// the consequences caused by calling it in a loop.

router/router_server_ws.go

@@ -51,8 +51,10 @@ func getServerWebsocket(c *gin.Context) {
 			continue
 		}
 
-		if err := handler.HandleInbound(j); err != nil {
+		go func(msg websocket.Message) {
-			handler.SendErrorJson(j, err)
+			if err := handler.HandleInbound(msg); err != nil {
-		}
+				handler.SendErrorJson(msg, err)
+			}
+		}(j)
 	}
 }

router/router_transfer.go

@@ -98,33 +98,33 @@ func postServerArchive(c *gin.Context) {
 		start := time.Now()
 
 		if err := server.Archiver.Archive(); err != nil {
-			zap.S().Errorw("failed to get archive for server", zap.String("server", s.Uuid), zap.Error(err))
+			zap.S().Errorw("failed to get archive for server", zap.String("server", server.Id()), zap.Error(err))
 			return
 		}
 
 		zap.S().Debugw(
 			"successfully created archive for server",
-			zap.String("server", server.Uuid),
+			zap.String("server", server.Id()),
 			zap.Duration("time", time.Now().Sub(start).Round(time.Microsecond)),
 		)
 
 		r := api.NewRequester()
-		rerr, err := r.SendArchiveStatus(server.Uuid, true)
+		rerr, err := r.SendArchiveStatus(server.Id(), true)
 		if rerr != nil || err != nil {
 			if err != nil {
-				zap.S().Errorw("failed to notify panel with archive status", zap.String("server", server.Uuid), zap.Error(err))
+				zap.S().Errorw("failed to notify panel with archive status", zap.String("server", server.Id()), zap.Error(err))
 				return
 			}
 
 			zap.S().Errorw(
 				"panel returned an error when sending the archive status",
-				zap.String("server", server.Uuid),
+				zap.String("server", server.Id()),
 				zap.Error(errors.New(rerr.String())),
 			)
 			return
 		}
 
-		zap.S().Debugw("successfully notified panel about archive status", zap.String("server", server.Uuid))
+		zap.S().Debugw("successfully notified panel about archive status", zap.String("server", server.Id()))
 	}(s)
 
 	c.Status(http.StatusAccepted)

router/tokens/websocket.go

@@ -4,10 +4,13 @@ import (
 	"encoding/json"
 	"github.com/gbrlsnchs/jwt/v3"
 	"strings"
+	"sync"
 )
 
 type WebsocketPayload struct {
 	jwt.Payload
+	sync.RWMutex
+
 	UserID      json.Number `json:"user_id"`
 	ServerUUID  string      `json:"server_uuid"`
 	Permissions []string    `json:"permissions"`
@@ -15,11 +18,24 @@ type WebsocketPayload struct {
 
 // Returns the JWT payload.
 func (p *WebsocketPayload) GetPayload() *jwt.Payload {
+	p.RLock()
+	defer p.RUnlock()
+
 	return &p.Payload
 }
 
+func (p *WebsocketPayload) GetServerUuid() string {
+	p.RLock()
+	defer p.RUnlock()
+
+	return p.ServerUUID
+}
+
 // Checks if the given token payload has a permission string.
 func (p *WebsocketPayload) HasPermission(permission string) bool {
+	p.RLock()
+	defer p.RUnlock()
+
 	for _, k := range p.Permissions {
 		if k == permission || (!strings.HasPrefix(permission, "admin") && k == "*") {
 			return true

router/websocket/listeners.go

@@ -43,6 +43,8 @@ func (h *Handler) ListenForServerEvents(ctx context.Context) {
 		server.StatusEvent,
 		server.ConsoleOutputEvent,
 		server.InstallOutputEvent,
+		server.InstallStartedEvent,
+		server.InstallCompletedEvent,
 		server.DaemonMessageEvent,
 		server.BackupCompletedEvent,
 	}
@@ -52,6 +54,7 @@ func (h *Handler) ListenForServerEvents(ctx context.Context) {
 		h.server.Events().Subscribe(event, eventChannel)
 	}
 
+	for d := range eventChannel {
 		select {
 		case <-ctx.Done():
 			for _, event := range events {
@@ -60,8 +63,6 @@ func (h *Handler) ListenForServerEvents(ctx context.Context) {
 
 			close(eventChannel)
 		default:
-		// Listen for different events emitted by the server and respond to them appropriately.
-		for d := range eventChannel {
 			h.SendJson(&Message{
 				Event: d.Topic,
 				Args:  []string{d.Data},

router/websocket/websocket.go

@@ -127,7 +127,7 @@ func (h *Handler) TokenValid() error {
 		return errors.New("jwt does not have connect permission")
 	}
 
-	if h.server.Uuid != j.ServerUUID {
+	if h.server.Id() != j.GetServerUuid() {
 		return errors.New("jwt server uuid mismatch")
 	}
 
@@ -247,16 +247,7 @@ func (h *Handler) HandleInbound(m Message) error {
 			if state == server.ProcessOfflineState {
 				_ = h.server.Filesystem.HasSpaceAvailable()
 
-				resources := server.ResourceUsage{
+				b, _ := json.Marshal(h.server.Proc())
-					Memory:      0,
-					MemoryLimit: 0,
-					CpuAbsolute: 0.0,
-					Disk:        h.server.Resources.Disk,
-				}
-				resources.Network.RxBytes = 0
-				resources.Network.TxBytes = 0
-
-				b, _ := json.Marshal(resources)
 				h.SendJson(&Message{
 					Event: server.StatsEvent,
 					Args:  []string{string(b)},
@@ -280,11 +271,14 @@ func (h *Handler) HandleInbound(m Message) error {
 				break
 			case "restart":
 				if h.GetJwt().HasPermission(PermissionSendPowerRestart) {
-					if err := h.server.Environment.WaitForStop(60, false); err != nil {
+					// If the server is alreay restarting don't do anything. Perhaps we send back an event
-						return err
+					// in the future for this? For now no reason to knowingly trigger an error by trying to
+					// restart a process already restarting.
+					if h.server.Environment.IsRestarting() {
+						return nil
 					}
 
-					return h.server.Environment.Start()
+					return h.server.Environment.Restart()
 				}
 				break
 			case "kill":

server/allocations.go

@@ -0,0 +1,17 @@
+package server
+
+// Defines the allocations available for a given server. When using the Docker environment
+// driver these correspond to mappings for the container that allow external connections.
+type Allocations struct {
+	// Defines the default allocation that should be used for this server. This is
+	// what will be used for {SERVER_IP} and {SERVER_PORT} when modifying configuration
+	// files or the startup arguments for a server.
+	DefaultMapping struct {
+		Ip   string `json:"ip"`
+		Port int    `json:"port"`
+	} `json:"default"`
+
+	// Mappings contains all of the ports that should be assigned to a given server
+	// attached to the IP they correspond to.
+	Mappings map[string][]int `json:"mappings"`
+}

server/archiver.go

@@ -23,7 +23,7 @@ func (a *Archiver) ArchivePath() string {
 
 // ArchiveName returns the name of the server's archive.
 func (a *Archiver) ArchiveName() string {
-	return a.Server.Uuid + ".tar.gz"
+	return a.Server.Id() + ".tar.gz"
 }
 
 // Exists returns a boolean based off if the archive exists.
@@ -52,7 +52,12 @@ func (a *Archiver) Archive() error {
 	}
 
 	for _, file := range fileInfo {
-		files = append(files, filepath.Join(path, file.Name()))
+		f, err := a.Server.Filesystem.SafeJoin(path, file)
+		if err != nil {
+			return err
+		}
+
+		files = append(files, f)
 	}
 
 	stat, err := a.Stat()

server/backup/archiver.go

@@ -20,9 +20,9 @@ type Archive struct {
 	Files      *IncludedFiles
 }
 
-// Creates an archive at dest with all of the files definied in the included files struct.
+// Creates an archive at dst with all of the files defined in the included files struct.
-func (a *Archive) Create(dest string, ctx context.Context) (os.FileInfo, error) {
+func (a *Archive) Create(dst string, ctx context.Context) (os.FileInfo, error) {
-	f, err := os.OpenFile(dest, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	f, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
 	if err != nil {
 		return nil, err
 	}
@@ -66,14 +66,17 @@ func (a *Archive) Create(dest string, ctx context.Context) (os.FileInfo, error)
 
 		// Attempt to remove the archive if there is an error, report that error to
 		// the logger if it fails.
-		if rerr := os.Remove(dest); rerr != nil && !os.IsNotExist(rerr) {
+		if rerr := os.Remove(dst); rerr != nil && !os.IsNotExist(rerr) {
-			log.WithField("location", dest).Warn("failed to delete corrupted backup archive")
+			log.WithField("location", dst).Warn("failed to delete corrupted backup archive")
 		}
 
 		return nil, err
 	}
 
-	st, _ := f.Stat()
+	st, err := f.Stat()
+	if err != nil {
+		return nil, err
+	}
 
 	return st, nil
 }
@@ -101,7 +104,7 @@ func (a *Archive) addToArchive(p string, s *os.FileInfo, w *tar.Writer) error {
 	a.Lock()
 	defer a.Unlock()
 
-	if err = w.WriteHeader(header); err != nil {
+	if err := w.WriteHeader(header); err != nil {
 		return err
 	}
 

server/build_settings.go

@@ -0,0 +1,72 @@
+package server
+
+import "math"
+
+// The build settings for a given server that impact docker container creation and
+// resource limits for a server instance.
+type BuildSettings struct {
+	// The total amount of memory in megabytes that this server is allowed to
+	// use on the host system.
+	MemoryLimit int64 `json:"memory_limit"`
+
+	// The amount of additional swap space to be provided to a container instance.
+	Swap int64 `json:"swap"`
+
+	// The relative weight for IO operations in a container. This is relative to other
+	// containers on the system and should be a value between 10 and 1000.
+	IoWeight uint16 `json:"io_weight"`
+
+	// The percentage of CPU that this instance is allowed to consume relative to
+	// the host. A value of 200% represents complete utilization of two cores. This
+	// should be a value between 1 and THREAD_COUNT * 100.
+	CpuLimit int64 `json:"cpu_limit"`
+
+	// The amount of disk space in megabytes that a server is allowed to use.
+	DiskSpace int64 `json:"disk_space"`
+
+	// Sets which CPU threads can be used by the docker instance.
+	Threads string `json:"threads"`
+}
+
+func (s *Server) Build() *BuildSettings {
+	return &s.Config().Build
+}
+
+// Converts the CPU limit for a server build into a number that can be better understood
+// by the Docker environment. If there is no limit set, return -1 which will indicate to
+// Docker that it has unlimited CPU quota.
+func (b *BuildSettings) ConvertedCpuLimit() int64 {
+	if b.CpuLimit == 0 {
+		return -1
+	}
+
+	return b.CpuLimit * 1000
+}
+
+// Set the hard limit for memory usage to be 5% more than the amount of memory assigned to
+// the server. If the memory limit for the server is < 4G, use 10%, if less than 2G use
+// 15%. This avoids unexpected crashes from processes like Java which run over the limit.
+func (b *BuildSettings) MemoryOverheadMultiplier() float64 {
+	if b.MemoryLimit <= 2048 {
+		return 1.15
+	} else if b.MemoryLimit <= 4096 {
+		return 1.10
+	}
+
+	return 1.05
+}
+
+func (b *BuildSettings) BoundedMemoryLimit() int64 {
+	return int64(math.Round(float64(b.MemoryLimit) * b.MemoryOverheadMultiplier() * 1_000_000))
+}
+
+// Returns the amount of swap available as a total in bytes. This is returned as the amount
+// of memory available to the server initially, PLUS the amount of additional swap to include
+// which is the format used by Docker.
+func (b *BuildSettings) ConvertedSwap() int64 {
+	if b.Swap < 0 {
+		return -1
+	}
+
+	return (b.Swap * 1_000_000) + b.BoundedMemoryLimit()
+}

server/config_parser.go

@@ -10,7 +10,8 @@ import (
 func (s *Server) UpdateConfigurationFiles() {
 	wg := new(sync.WaitGroup)
 
-	for _, v := range s.processConfiguration.ConfigurationFiles {
+	files := s.ProcessConfiguration().ConfigurationFiles
+	for _, v := range files {
 		wg.Add(1)
 
 		go func(f parser.ConfigurationFile, server *Server) {

server/configuration.go

@@ -0,0 +1,91 @@
+package server
+
+import (
+	"fmt"
+	"strconv"
+	"sync"
+)
+
+type EnvironmentVariables map[string]interface{}
+
+// Ugly hacky function to handle environment variables that get passed through as not-a-string
+// from the Panel. Ideally we'd just say only pass strings, but that is a fragile idea and if a
+// string wasn't passed through you'd cause a crash or the server to become unavailable. For now
+// try to handle the most likely values from the JSON and hope for the best.
+func (ev EnvironmentVariables) Get(key string) string {
+	val, ok := ev[key]
+	if !ok {
+		return ""
+	}
+
+	switch val.(type) {
+	case int:
+		return strconv.Itoa(val.(int))
+	case int32:
+		return strconv.FormatInt(val.(int64), 10)
+	case int64:
+		return strconv.FormatInt(val.(int64), 10)
+	case float32:
+		return fmt.Sprintf("%f", val.(float32))
+	case float64:
+		return fmt.Sprintf("%f", val.(float64))
+	case bool:
+		return strconv.FormatBool(val.(bool))
+	}
+
+	return val.(string)
+}
+
+type Configuration struct {
+	mu sync.RWMutex
+
+	// The unique identifier for the server that should be used when referencing
+	// it against the Panel API (and internally). This will be used when naming
+	// docker containers as well as in log output.
+	Uuid string `json:"uuid"`
+
+	// Whether or not the server is in a suspended state. Suspended servers cannot
+	// be started or modified except in certain scenarios by an admin user.
+	Suspended bool `json:"suspended"`
+
+	// The command that should be used when booting up the server instance.
+	Invocation string `json:"invocation"`
+
+	// An array of environment variables that should be passed along to the running
+	// server process.
+	EnvVars EnvironmentVariables `json:"environment"`
+
+	Allocations           Allocations   `json:"allocations"`
+	Build                 BuildSettings `json:"build"`
+	CrashDetectionEnabled bool          `default:"true" json:"enabled" yaml:"enabled"`
+	Mounts                []Mount       `json:"mounts"`
+	Resources             ResourceUsage `json:"resources"`
+
+	Container struct {
+		// Defines the Docker image that will be used for this server
+		Image string `json:"image,omitempty"`
+		// If set to true, OOM killer will be disabled on the server's Docker container.
+		// If not present (nil) we will default to disabling it.
+		OomDisabled bool `default:"true" json:"oom_disabled"`
+	} `json:"container,omitempty"`
+}
+
+func (s *Server) Config() *Configuration {
+	s.cfg.mu.RLock()
+	defer s.cfg.mu.RUnlock()
+
+	return &s.cfg
+}
+
+func (c *Configuration) GetUuid() string {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	return c.Uuid
+}
+
+func (c *Configuration) SetSuspended(s bool) {
+	c.mu.Lock()
+	c.Suspended = s
+	c.mu.Unlock()
+}

server/crash.go

@@ -4,18 +4,32 @@ import (
 	"fmt"
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/config"
+	"sync"
 	"time"
 )
 
-type CrashDetection struct {
+type CrashHandler struct {
-	// If set to false, the system will not listen for crash detection events that
+	mu sync.RWMutex
-	// can indicate that the server stopped unexpectedly.
-	Enabled bool `default:"true" json:"enabled" yaml:"enabled"`
 
 	// Tracks the time of the last server crash event.
 	lastCrash time.Time
 }
 
+// Returns the time of the last crash for this server instance.
+func (cd *CrashHandler) LastCrashTime() time.Time {
+	cd.mu.RLock()
+	defer cd.mu.RUnlock()
+
+	return cd.lastCrash
+}
+
+// Sets the last crash time for a server.
+func (cd *CrashHandler) SetLastCrash(t time.Time) {
+	cd.mu.Lock()
+	cd.lastCrash = t
+	cd.mu.Unlock()
+}
+
 // Looks at the environment exit state to determine if the process exited cleanly or
 // if it was the result of an event that we should try to recover from.
 //
@@ -30,8 +44,8 @@ func (s *Server) handleServerCrash() error {
 	// No point in doing anything here if the server isn't currently offline, there
 	// is no reason to do a crash detection event. If the server crash detection is
 	// disabled we want to skip anything after this as well.
-	if s.GetState() != ProcessOfflineState || !s.CrashDetection.Enabled {
+	if s.GetState() != ProcessOfflineState || !s.Config().CrashDetectionEnabled {
-		if !s.CrashDetection.Enabled {
+		if !s.Config().CrashDetectionEnabled {
 			s.Log().Debug("server triggered crash detection but handler is disabled for server process")
 
 			s.PublishConsoleOutputFromDaemon("Server detected as crashed; crash detection is disabled for this instance.")
@@ -57,7 +71,7 @@ func (s *Server) handleServerCrash() error {
 	s.PublishConsoleOutputFromDaemon(fmt.Sprintf("Exit code: %d", exitCode))
 	s.PublishConsoleOutputFromDaemon(fmt.Sprintf("Out of memory: %t", oomKilled))
 
-	c := s.CrashDetection.lastCrash
+	c := s.crasher.LastCrashTime()
 	// If the last crash time was within the last 60 seconds we do not want to perform
 	// an automatic reboot of the process. Return an error that can be handled.
 	if !c.IsZero() && c.Add(time.Second * 60).After(time.Now()) {
@@ -66,7 +80,7 @@ func (s *Server) handleServerCrash() error {
 		return &crashTooFrequent{}
 	}
 
-	s.CrashDetection.lastCrash = time.Now()
+	s.crasher.SetLastCrash(time.Now())
 
 	return s.Environment.Start()
 }

server/environment.go

@@ -31,6 +31,13 @@ type Environment interface {
 	// not be returned.
 	Stop() error
 
+	// Restart a server instance. If already stopped the process will be started. This function
+	// will return an error if the server is already performing a restart process as to avoid
+	// unnecessary double/triple/quad looping issues if multiple people press restart or spam the
+	// button to restart.
+	Restart() error
+	IsRestarting() bool
+
 	// Waits for a server instance to stop gracefully. If the server is still detected
 	// as running after seconds, an error will be returned, or the server will be terminated
 	// depending on the value of the second argument.

server/environment_docker.go

@@ -16,16 +16,20 @@ import (
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/api"
 	"github.com/pterodactyl/wings/config"
+	"golang.org/x/sync/semaphore"
 	"io"
 	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
 // Defines the base environment for Docker instances running through Wings.
 type DockerEnvironment struct {
+	sync.RWMutex
+
 	Server *Server
 
 	// The Docker client being used for this instance.
@@ -43,6 +47,25 @@ type DockerEnvironment struct {
 	// Holds the stats stream used by the polling commands so that we can easily close
 	// it out.
 	stats io.ReadCloser
+
+	// Locks when we're performing a restart to avoid trying to restart a process that is already
+	// being restarted.
+	restartSem *semaphore.Weighted
+}
+
+// Set if this process is currently attached to the process.
+func (d *DockerEnvironment) SetAttached(a bool) {
+	d.Lock()
+	d.attached = a
+	d.Unlock()
+}
+
+// Determine if the this process is currently attached to the container.
+func (d *DockerEnvironment) IsAttached() bool {
+	d.RLock()
+	defer d.RUnlock()
+
+	return d.attached
 }
 
 // Creates a new base Docker environment. A server must still be attached to it.
@@ -71,7 +94,7 @@ func (d *DockerEnvironment) Type() string {
 
 // Determines if the container exists in this environment.
 func (d *DockerEnvironment) Exists() (bool, error) {
-	_, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	_, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 
 	if err != nil {
 		// If this error is because the container instance wasn't found via Docker we
@@ -95,7 +118,7 @@ func (d *DockerEnvironment) Exists() (bool, error) {
 //
 // @see docker/client/errors.go
 func (d *DockerEnvironment) IsRunning() (bool, error) {
-	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		return false, err
 	}
@@ -107,7 +130,7 @@ func (d *DockerEnvironment) IsRunning() (bool, error) {
 // making any changes to the operational state of the container. This allows memory, cpu,
 // and IO limitations to be adjusted on the fly for individual instances.
 func (d *DockerEnvironment) InSituUpdate() error {
-	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid); err != nil {
+	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Id()); 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
@@ -129,7 +152,7 @@ func (d *DockerEnvironment) InSituUpdate() error {
 
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
 	defer cancel()
-	if _, err := d.Client.ContainerUpdate(ctx, d.Server.Uuid, u); err != nil {
+	if _, err := d.Client.ContainerUpdate(ctx, d.Server.Id(), u); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -155,7 +178,7 @@ func (d *DockerEnvironment) OnBeforeStart() error {
 
 	// Always destroy and re-create the server container to ensure that synced data from
 	// the Panel is used.
-	if err := d.Client.ContainerRemove(context.Background(), d.Server.Uuid, types.ContainerRemoveOptions{RemoveVolumes: true}); err != nil {
+	if err := d.Client.ContainerRemove(context.Background(), d.Server.Id(), types.ContainerRemoveOptions{RemoveVolumes: true}); err != nil {
 		if !client.IsErrNotFound(err) {
 			return err
 		}
@@ -199,11 +222,11 @@ func (d *DockerEnvironment) Start() error {
 	// Theoretically you'd have the Panel handle all of this logic, but we cannot do that
 	// because we allow the websocket to control the server power state as well, so we'll
 	// need to handle that action in here.
-	if d.Server.Suspended {
+	if d.Server.IsSuspended() {
 		return &suspendedError{}
 	}
 
-	if c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid); err != nil {
+	if c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id()); 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 againt
 		// a nil-pointer when checking c.State below.
@@ -258,7 +281,7 @@ func (d *DockerEnvironment) Start() error {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
 	defer cancel()
 
-	if err := d.Client.ContainerStart(ctx, d.Server.Uuid, types.ContainerStartOptions{}); err != nil {
+	if err := d.Client.ContainerStart(ctx, d.Server.Id(), types.ContainerStartOptions{}); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -271,19 +294,89 @@ func (d *DockerEnvironment) Start() error {
 // Stops the container that the server is running in. This will allow up to 10
 // seconds to pass before a failure occurs.
 func (d *DockerEnvironment) Stop() error {
-	stop := d.Server.processConfiguration.Stop
+	stop := d.Server.ProcessConfiguration().Stop
 	if stop.Type == api.ProcessStopSignal {
 		return d.Terminate(os.Kill)
 	}
 
 	d.Server.SetState(ProcessStoppingState)
-	if stop.Type == api.ProcessStopCommand {
+	// Only attempt to send the stop command to the instance if we are actually attached to
+	// the instance. If we are not for some reason, just send the container stop event.
+	if d.IsAttached() && stop.Type == api.ProcessStopCommand {
 		return d.SendCommand(stop.Value)
 	}
 
 	t := time.Second * 10
 
-	return d.Client.ContainerStop(context.Background(), d.Server.Uuid, &t)
+	err := d.Client.ContainerStop(context.Background(), d.Server.Id(), &t)
+	if err != nil {
+		// If the container does not exist just mark the process as stopped and return without
+		// an error.
+		if client.IsErrNotFound(err) {
+			d.SetAttached(false)
+			d.Server.SetState(ProcessOfflineState)
+
+			return nil
+		}
+
+		return err
+	}
+
+	return nil
+}
+
+// Try to acquire a lock to restart the server. If one cannot be obtained within 5 seconds return
+// an error to the caller. You should ideally be checking IsRestarting() before calling this function
+// to avoid unnecessary delays since you can respond immediately from that.
+func (d *DockerEnvironment) acquireRestartLock() error {
+	if d.restartSem == nil {
+		d.restartSem = semaphore.NewWeighted(1)
+	}
+
+	ctx, _ := context.WithTimeout(context.Background(), time.Second*5)
+
+	return d.restartSem.Acquire(ctx, 1)
+}
+
+// Restarts the server process by waiting for the process to gracefully stop and then triggering a
+// start command. This will return an error if there is already a restart process executing for the
+// server. The lock is released when the process is stopped and a start has begun.
+func (d *DockerEnvironment) Restart() error {
+	d.Server.Log().Debug("attempting to acquire restart lock...")
+	if err := d.acquireRestartLock(); err != nil {
+		d.Server.Log().Warn("failed to acquire restart lock; already acquired by a different process")
+		return err
+	}
+
+	d.Server.Log().Debug("acquired restart lock")
+
+	err := d.WaitForStop(60, false)
+	if err != nil {
+		d.restartSem.Release(1)
+		return err
+	}
+
+	// Release the restart lock, it is now safe for someone to attempt restarting the server again.
+	d.restartSem.Release(1)
+
+	// Start the process.
+	return d.Start()
+}
+
+// Check if the server is currently running the restart process by checking if there is a semaphore
+// allocated, and if so, if we can aquire a lock on it.
+func (d *DockerEnvironment) IsRestarting() bool {
+	if d.restartSem == nil {
+		return false
+	}
+
+	if d.restartSem.TryAcquire(1) {
+		d.restartSem.Release(1)
+
+		return false
+	}
+
+	return true
 }
 
 // Attempts to gracefully stop a server using the defined stop command. If the server
@@ -304,7 +397,7 @@ func (d *DockerEnvironment) WaitForStop(seconds int, terminate bool) error {
 	// 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 := d.Client.ContainerWait(ctx, d.Server.Uuid, container.WaitConditionNotRunning)
+	ok, errChan := d.Client.ContainerWait(ctx, d.Server.Id(), container.WaitConditionNotRunning)
 	select {
 	case <-ctx.Done():
 		if ctxErr := ctx.Err(); ctxErr != nil {
@@ -326,7 +419,7 @@ func (d *DockerEnvironment) WaitForStop(seconds int, terminate bool) error {
 
 // Forcefully terminates the container using the signal passed through.
 func (d *DockerEnvironment) Terminate(signal os.Signal) error {
-	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		return errors.WithStack(err)
 	}
@@ -338,7 +431,7 @@ func (d *DockerEnvironment) Terminate(signal os.Signal) error {
 	d.Server.SetState(ProcessStoppingState)
 
 	return d.Client.ContainerKill(
-		context.Background(), d.Server.Uuid, strings.TrimSuffix(strings.TrimPrefix(signal.String(), "signal "), "ed"),
+		context.Background(), d.Server.Id(), strings.TrimSuffix(strings.TrimPrefix(signal.String(), "signal "), "ed"),
 	)
 }
 
@@ -348,7 +441,7 @@ func (d *DockerEnvironment) Destroy() error {
 	// Avoid crash detection firing off.
 	d.Server.SetState(ProcessStoppingState)
 
-	err := d.Client.ContainerRemove(context.Background(), d.Server.Uuid, types.ContainerRemoveOptions{
+	err := d.Client.ContainerRemove(context.Background(), d.Server.Id(), types.ContainerRemoveOptions{
 		RemoveVolumes: true,
 		RemoveLinks:   false,
 		Force:         true,
@@ -368,7 +461,7 @@ func (d *DockerEnvironment) Destroy() error {
 // Determine the container exit state and return the exit code and wether or not
 // the container was killed by the OOM killer.
 func (d *DockerEnvironment) ExitState() (uint32, bool, error) {
-	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	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
@@ -394,7 +487,7 @@ func (d *DockerEnvironment) ExitState() (uint32, bool, error) {
 // miss important output at the beginning because of the time delay with attaching to the
 // output.
 func (d *DockerEnvironment) Attach() error {
-	if d.attached {
+	if d.IsAttached() {
 		return nil
 	}
 
@@ -403,7 +496,7 @@ func (d *DockerEnvironment) Attach() error {
 	}
 
 	var err error
-	d.stream, err = d.Client.ContainerAttach(context.Background(), d.Server.Uuid, types.ContainerAttachOptions{
+	d.stream, err = d.Client.ContainerAttach(context.Background(), d.Server.Id(), types.ContainerAttachOptions{
 		Stdin:  true,
 		Stdout: true,
 		Stderr: true,
@@ -418,7 +511,7 @@ func (d *DockerEnvironment) Attach() error {
 		Server: d.Server,
 	}
 
-	d.attached = true
+	d.SetAttached(true)
 	go func() {
 		if err := d.EnableResourcePolling(); err != nil {
 			d.Server.Log().WithField("error", errors.WithStack(err)).Warn("failed to enable resource polling on server")
@@ -429,7 +522,7 @@ func (d *DockerEnvironment) Attach() error {
 		defer d.stream.Close()
 		defer func() {
 			d.Server.SetState(ProcessOfflineState)
-			d.attached = false
+			d.SetAttached(false)
 		}()
 
 		io.Copy(console, d.stream.Reader)
@@ -447,7 +540,7 @@ func (d *DockerEnvironment) FollowConsoleOutput() error {
 			return errors.WithStack(err)
 		}
 
-		return errors.New(fmt.Sprintf("no such container: %s", d.Server.Uuid))
+		return errors.New(fmt.Sprintf("no such container: %s", d.Server.Id()))
 	}
 
 	opts := types.ContainerLogsOptions{
@@ -457,7 +550,7 @@ func (d *DockerEnvironment) FollowConsoleOutput() error {
 		Since:      time.Now().Format(time.RFC3339),
 	}
 
-	reader, err := d.Client.ContainerLogs(context.Background(), d.Server.Uuid, opts)
+	reader, err := d.Client.ContainerLogs(context.Background(), d.Server.Id(), opts)
 
 	go func(r io.ReadCloser) {
 		defer r.Close()
@@ -483,7 +576,7 @@ func (d *DockerEnvironment) EnableResourcePolling() error {
 		return errors.New("cannot enable resource polling on a server that is not running")
 	}
 
-	stats, err := d.Client.ContainerStats(context.Background(), d.Server.Uuid, true)
+	stats, err := d.Client.ContainerStats(context.Background(), d.Server.Id(), true)
 	if err != nil {
 		return errors.WithStack(err)
 	}
@@ -510,20 +603,16 @@ func (d *DockerEnvironment) EnableResourcePolling() error {
 				return
 			}
 
-			s.Resources.CpuAbsolute = s.Resources.CalculateAbsoluteCpu(&v.PreCPUStats, &v.CPUStats)
+			s.Proc().UpdateFromDocker(v)
-			s.Resources.Memory = s.Resources.CalculateDockerMemory(v.MemoryStats)
+			for _, nw := range v.Networks {
-			s.Resources.MemoryLimit = v.MemoryStats.Limit
+				s.Proc().UpdateNetworkBytes(&nw)
+			}
 
 			// Why you ask? This already has the logic for caching disk space in use and then
 			// also handles pushing that value to the resources object automatically.
 			s.Filesystem.HasSpaceAvailable()
 
-			for _, nw := range v.Networks {
+			b, _ := json.Marshal(s.Proc())
-				s.Resources.Network.RxBytes += nw.RxBytes
-				s.Resources.Network.TxBytes += nw.TxBytes
-			}
-
-			b, _ := json.Marshal(s.Resources)
 			s.Events().Publish(StatsEvent, string(b))
 		}
 	}(d.Server)
@@ -538,15 +627,16 @@ func (d *DockerEnvironment) DisableResourcePolling() error {
 	}
 
 	err := d.stats.Close()
-
+	d.Server.Proc().Empty()
-	d.Server.Resources.CpuAbsolute = 0
-	d.Server.Resources.Memory = 0
-	d.Server.Resources.Network.TxBytes = 0
-	d.Server.Resources.Network.RxBytes = 0
 
 	return errors.WithStack(err)
 }
 
+// Returns the image to be used for the instance.
+func (d *DockerEnvironment) Image() string {
+	return d.Server.Config().Container.Image
+}
+
 // 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.
@@ -564,7 +654,7 @@ func (d *DockerEnvironment) ensureImageExists() error {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute*15)
 	defer cancel()
 
-	out, err := d.Client.ImagePull(ctx, d.Server.Container.Image, types.ImagePullOptions{All: false})
+	out, err := d.Client.ImagePull(ctx, d.Image(), types.ImagePullOptions{All: false})
 	if err != nil {
 		images, ierr := d.Client.ImageList(ctx, types.ImageListOptions{})
 		if ierr != nil {
@@ -575,12 +665,12 @@ func (d *DockerEnvironment) ensureImageExists() error {
 
 		for _, img := range images {
 			for _, t := range img.RepoTags {
-				if t != d.Server.Container.Image {
+				if t != d.Image() {
 					continue
 				}
 
 				d.Server.Log().WithFields(log.Fields{
-					"image": d.Server.Container.Image,
+					"image": d.Image(),
 					"error": errors.New(err.Error()),
 				}).Warn("unable to pull requested image from remote source, however the image exists locally")
 
@@ -594,7 +684,7 @@ func (d *DockerEnvironment) ensureImageExists() error {
 	}
 	defer out.Close()
 
-	log.WithField("image", d.Server.Container.Image).Debug("pulling docker image... this could take a bit of time")
+	log.WithField("image", d.Image()).Debug("pulling docker image... this could take a bit of time")
 
 	// I'm not sure what the best approach here is, but this will block execution until the image
 	// is done being pulled, which is what we need.
@@ -621,7 +711,7 @@ func (d *DockerEnvironment) 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 := d.Client.ContainerInspect(context.Background(), d.Server.Uuid); err == nil {
+	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Id()); err == nil {
 		return nil
 	} else if !client.IsErrNotFound(err) {
 		return errors.WithStack(err)
@@ -633,7 +723,7 @@ func (d *DockerEnvironment) Create() error {
 	}
 
 	conf := &container.Config{
-		Hostname:     d.Server.Uuid,
+		Hostname:     d.Server.Id(),
 		Domainname:   config.Get().Docker.Domainname,
 		User:         strconv.Itoa(config.Get().System.User.Uid),
 		AttachStdin:  true,
@@ -641,12 +731,9 @@ func (d *DockerEnvironment) Create() error {
 		AttachStderr: true,
 		OpenStdin:    true,
 		Tty:          true,
-
 		ExposedPorts: d.exposedPorts(),
-
+		Image:        d.Image(),
-		Image: d.Server.Container.Image,
 		Env:          d.Server.GetEnvironmentVariables(),
-
 		Labels: map[string]string{
 			"Service":       "Pterodactyl",
 			"ContainerType": "server_process",
@@ -663,7 +750,7 @@ func (d *DockerEnvironment) Create() error {
 	}
 
 	var mounted bool
-	for _, m := range d.Server.Mounts {
+	for _, m := range d.Server.Config().Mounts {
 		mounted = false
 		source := filepath.Clean(m.Source)
 		target := filepath.Clean(m.Target)
@@ -685,16 +772,17 @@ func (d *DockerEnvironment) Create() error {
 			break
 		}
 
-		log := log.WithFields(log.Fields{
+		logger := log.WithFields(log.Fields{
-			"server":      d.Server.Uuid,
+			"server":      d.Server.Id(),
 			"source_path": source,
 			"target_path": target,
 			"read_only":   m.ReadOnly,
 		})
+
 		if mounted {
-			log.Debug("attaching mount to server's container")
+			logger.Debug("attaching mount to server's container")
 		} else {
-			log.Warn("skipping mount because it isn't allowed")
+			logger.Warn("skipping mount because it isn't allowed")
 		}
 	}
 
@@ -738,7 +826,7 @@ func (d *DockerEnvironment) Create() error {
 		NetworkMode: container.NetworkMode(config.Get().Docker.Network.Mode),
 	}
 
-	if _, err := d.Client.ContainerCreate(context.Background(), conf, hostConf, nil, d.Server.Uuid); err != nil {
+	if _, err := d.Client.ContainerCreate(context.Background(), conf, hostConf, nil, d.Server.Id()); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -748,7 +836,7 @@ func (d *DockerEnvironment) Create() error {
 // Sends the specified command to the stdin of the running container instance. There is no
 // confirmation that this data is sent successfully, only that it gets pushed into the stdin.
 func (d *DockerEnvironment) SendCommand(c string) error {
-	if !d.attached {
+	if !d.IsAttached() {
 		return errors.New("attempting to send command to non-attached instance")
 	}
 
@@ -760,7 +848,7 @@ func (d *DockerEnvironment) SendCommand(c string) error {
 // Reads the log file for the server. This does not care if the server is running or not, it will
 // simply try to read the last X bytes of the file and return them.
 func (d *DockerEnvironment) Readlog(len int64) ([]string, error) {
-	j, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	j, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		return nil, err
 	}
@@ -837,7 +925,7 @@ func (d *DockerEnvironment) parseLogToStrings(b []byte) ([]string, error) {
 func (d *DockerEnvironment) portBindings() nat.PortMap {
 	var out = nat.PortMap{}
 
-	for ip, ports := range d.Server.Allocations.Mappings {
+	for ip, ports := range d.Server.Config().Allocations.Mappings {
 		for _, port := range ports {
 			// Skip over invalid ports.
 			if port < 0 || port > 65535 {
@@ -887,14 +975,14 @@ func (d *DockerEnvironment) exposedPorts() nat.PortSet {
 // the same or higher than the memory limit.
 func (d *DockerEnvironment) getResourcesForServer() container.Resources {
 	return container.Resources{
-		Memory:            d.Server.Build.BoundedMemoryLimit(),
+		Memory:            d.Server.Build().BoundedMemoryLimit(),
-		MemoryReservation: d.Server.Build.MemoryLimit * 1_000_000,
+		MemoryReservation: d.Server.Build().MemoryLimit * 1_000_000,
-		MemorySwap:        d.Server.Build.ConvertedSwap(),
+		MemorySwap:        d.Server.Build().ConvertedSwap(),
-		CPUQuota:          d.Server.Build.ConvertedCpuLimit(),
+		CPUQuota:          d.Server.Build().ConvertedCpuLimit(),
 		CPUPeriod:         100_000,
 		CPUShares:         1024,
-		BlkioWeight:       d.Server.Build.IoWeight,
+		BlkioWeight:       d.Server.Build().IoWeight,
-		OomKillDisable:    &d.Server.Container.OomDisabled,
+		OomKillDisable:    &d.Server.Config().Container.OomDisabled,
-		CpusetCpus:        d.Server.Build.Threads,
+		CpusetCpus:        d.Server.Build().Threads,
 	}
 }

server/events.go

@@ -11,6 +11,8 @@ import (
 const (
 	DaemonMessageEvent    = "daemon message"
 	InstallOutputEvent    = "install output"
+	InstallStartedEvent   = "install started"
+	InstallCompletedEvent = "install completed"
 	ConsoleOutputEvent    = "console output"
 	StatusEvent           = "status"
 	StatsEvent            = "stats"
@@ -30,6 +32,9 @@ type EventBus struct {
 
 // Returns the server's emitter instance.
 func (s *Server) Events() *EventBus {
+	s.emitterLock.Lock()
+	defer s.emitterLock.Unlock()
+
 	if s.emitter == nil {
 		s.emitter = &EventBus{
 			subscribers: map[string][]chan Event{},
@@ -83,11 +88,27 @@ func (e *EventBus) Subscribe(topic string, ch chan Event) {
 	e.Lock()
 	defer e.Unlock()
 
-	if p, ok := e.subscribers[topic]; ok {
+	p, ok := e.subscribers[topic]
-		e.subscribers[topic] = append(p, ch)
+
-	} else {
+	// If there is nothing currently subscribed to this topic just go ahead and create
+	// the item and then return.
+	if !ok {
 		e.subscribers[topic] = append([]chan Event{}, ch)
+		return
 	}
+
+	// If this topic is already setup, first iterate over the event channels currently in there
+	// and confirm there is not a match. If there _is_ a match do nothing since that means this
+	// channel is already being tracked. This avoids registering two identical handlers for the
+	// same topic, and means the Unsubscribe function can safely assume there will only be a
+	// single match for an event.
+	for i := range e.subscribers[topic] {
+		if ch == e.subscribers[topic][i] {
+			return
+		}
+	}
+
+	e.subscribers[topic] = append(p, ch)
 }
 
 // Unsubscribe a channel from a topic.
@@ -99,6 +120,10 @@ func (e *EventBus) Unsubscribe(topic string, ch chan Event) {
 		for i := range e.subscribers[topic] {
 			if ch == e.subscribers[topic][i] {
 				e.subscribers[topic] = append(e.subscribers[topic][:i], e.subscribers[topic][i+1:]...)
+				// Subscribe enforces a unique event channel for the topic, so we can safely exit
+				// this loop once matched since there should not be any additional matches after
+				// this point.
+				break
 			}
 		}
 	}

server/filesystem.go

@@ -26,18 +26,27 @@ import (
 )
 
 // Error returned when there is a bad path provided to one of the FS calls.
-var InvalidPathResolution = errors.New("invalid path resolution")
+type PathResolutionError struct{}
+
+// Returns the error response in a string form that can be more easily consumed.
+func (pre PathResolutionError) Error() string {
+	return "invalid path resolution"
+}
+
+func IsPathResolutionError(err error) bool {
+	_, ok := err.(PathResolutionError)
+
+	return ok
+}
 
 type Filesystem struct {
-	// The server object associated with this Filesystem.
 	Server        *Server
-
+	cacheDiskMu   sync.Mutex
-	Configuration *config.SystemConfiguration
 }
 
 // Returns the root path that contains all of a server's data.
 func (fs *Filesystem) Path() string {
-	return filepath.Join(fs.Configuration.Data, fs.Server.Uuid)
+	return filepath.Join(config.Get().System.Data, fs.Server.Id())
 }
 
 // Normalizes a directory being passed in to ensure the user is not able to escape
@@ -49,12 +58,8 @@ func (fs *Filesystem) Path() string {
 func (fs *Filesystem) SafePath(p string) (string, error) {
 	var nonExistentPathResolution string
 
-	// Calling filpath.Clean on the joined directory will resolve it to the absolute path,
+	// Start with a cleaned up path before checking the more complex bits.
-	// removing any ../ type of resolution arguments, and leaving us with a direct path link.
+	r := fs.unsafeFilePath(p)
-	//
-	// This will also trim the existing root path off the beginning of the path passed to
-	// the function since that can get a bit messy.
-	r := filepath.Clean(filepath.Join(fs.Path(), strings.TrimPrefix(p, fs.Path())))
 
 	// At the same time, evaluate the symlink status and determine where this file or folder
 	// is truly pointing to.
@@ -72,7 +77,7 @@ func (fs *Filesystem) SafePath(p string) (string, error) {
 		for k := range parts {
 			try = strings.Join(parts[:(len(parts)-k)], "/")
 
-			if !strings.HasPrefix(try, fs.Path()) {
+			if !fs.unsafeIsInDataDirectory(try) {
 				break
 			}
 
@@ -87,8 +92,8 @@ func (fs *Filesystem) SafePath(p string) (string, error) {
 	// If the new path doesn't start with their root directory there is clearly an escape
 	// attempt going on, and we should NOT resolve this path for them.
 	if nonExistentPathResolution != "" {
-		if !strings.HasPrefix(nonExistentPathResolution, fs.Path()) {
+		if !fs.unsafeIsInDataDirectory(nonExistentPathResolution) {
-			return "", InvalidPathResolution
+			return "", PathResolutionError{}
 		}
 
 		// If the nonExistentPathResolution variable is not empty then the initial path requested
@@ -101,11 +106,51 @@ func (fs *Filesystem) SafePath(p string) (string, error) {
 	// If the requested directory from EvalSymlinks begins with the server root directory go
 	// ahead and return it. If not we'll return an error which will block any further action
 	// on the file.
-	if strings.HasPrefix(p, fs.Path()) {
+	if fs.unsafeIsInDataDirectory(p) {
 		return p, nil
 	}
 
-	return "", InvalidPathResolution
+	return "", PathResolutionError{}
+}
+
+// Generate a path to the file by cleaning it up and appending the root server path to it. This
+// DOES NOT gaurantee that the file resolves within the server data directory. You'll want to use
+// the fs.unsafeIsInDataDirectory(p) function to confirm.
+func (fs *Filesystem) unsafeFilePath(p string) string {
+	// Calling filpath.Clean on the joined directory will resolve it to the absolute path,
+	// removing any ../ type of resolution arguments, and leaving us with a direct path link.
+	//
+	// This will also trim the existing root path off the beginning of the path passed to
+	// the function since that can get a bit messy.
+	return filepath.Clean(filepath.Join(fs.Path(), strings.TrimPrefix(p, fs.Path())))
+}
+
+// Check that that path string starts with the server data directory path. This function DOES NOT
+// validate that the rest of the path does not end up resolving out of this directory, or that the
+// targeted file or folder is not a symlink doing the same thing.
+func (fs *Filesystem) unsafeIsInDataDirectory(p string) bool {
+	return strings.HasPrefix(strings.TrimSuffix(p, "/")+"/", strings.TrimSuffix(fs.Path(), "/")+"/")
+}
+
+// Helper function to keep some of the codebase a little cleaner. Returns a "safe" version of the path
+// joined with a file. This is important because you cannot just assume that appending a file to a cleaned
+// path will result in a cleaned path to that file. For example, imagine you have the following scenario:
+//
+// my_bad_file -> symlink:/etc/passwd
+//
+// cleaned := SafePath("../../etc") -> "/"
+// filepath.Join(cleaned, my_bad_file) -> "/my_bad_file"
+//
+// You might think that "/my_bad_file" is fine since it isn't pointing to the original "../../etc/my_bad_file".
+// However, this doesn't account for symlinks where the file might be pointing outside of the directory, so
+// calling a function such as Chown against it would chown the symlinked location, and not the file within the
+// Wings daemon.
+func (fs *Filesystem) SafeJoin(dir string, f os.FileInfo) (string, error) {
+	if f.Mode()&os.ModeSymlink != 0 {
+		return fs.SafePath(filepath.Join(dir, f.Name()))
+	}
+
+	return filepath.Join(dir, f.Name()), nil
 }
 
 // Executes the fs.SafePath function in parallel against an array of paths. If any of the calls
@@ -162,18 +207,45 @@ func (fs *Filesystem) ParallelSafePath(paths []string) ([]string, error) {
 // Because determining the amount of space being used by a server is a taxing operation we
 // will load it all up into a cache and pull from that as long as the key is not expired.
 func (fs *Filesystem) HasSpaceAvailable() bool {
-	var space = fs.Server.Build.DiskSpace
+	space := fs.Server.Build().DiskSpace
+
+	size, err := fs.getCachedDiskUsage()
+	if err != nil {
+		fs.Server.Log().WithField("error", err).Warn("failed to determine root server directory size")
+	}
+
+	// Determine if their folder size, in bytes, is smaller than the amount of space they've
+	// been allocated.
+	fs.Server.Proc().SetDisk(size)
 
 	// If space is -1 or 0 just return true, means they're allowed unlimited.
+	//
+	// Technically we could skip disk space calculation because we don't need to check if the server exceeds it's limit
+	// but because this method caches the disk usage it would be best to calculate the disk usage and always
+	// return true.
 	if space <= 0 {
 		return true
 	}
 
-	// If we have a match in the cache, use that value in the return. No need to perform an expensive
+	return (size / 1000.0 / 1000.0) <= space
-	// disk operation, even if this is an empty value.
+}
-	if x, exists := fs.Server.Cache.Get("disk_used"); exists {
+
-		fs.Server.Resources.Disk = x.(int64)
+// Internal helper function to allow other parts of the codebase to check the total used disk space
-		return (x.(int64) / 1000.0 / 1000.0) <= space
+// as needed without overly taxing the system. This will prioritize the value from the cache to avoid
+// excessive IO usage. We will only walk the filesystem and determine the size of the directory if there
+// is no longer a cached value.
+func (fs *Filesystem) getCachedDiskUsage() (int64, error) {
+	// Obtain an exclusive lock on this process so that we don't unintentionally run it at the same
+	// time as another running process. Once the lock is available it'll read from the cache for the
+	// second call rather than hitting the disk in parallel.
+	//
+	// This effectively the same speed as running this call in parallel since this cache will return
+	// instantly on the second call.
+	fs.cacheDiskMu.Lock()
+	defer fs.cacheDiskMu.Unlock()
+
+	if x, exists := fs.Server.cache.Get("disk_used"); exists {
+		return x.(int64), nil
 	}
 
 	// If there is no size its either because there is no data (in which case running this function
@@ -181,37 +253,30 @@ func (fs *Filesystem) HasSpaceAvailable() bool {
 	// grab the size of their data directory. This is a taxing operation, so we want to store it in
 	// the cache once we've gotten it.
 	size, err := fs.DirectorySize("/")
-	if err != nil {
-		fs.Server.Log().WithField("error", err).Warn("failed to determine root server directory size")
-	}
 
 	// Always cache the size, even if there is an error. We want to always return that value
 	// so that we don't cause an endless loop of determining the disk size if there is a temporary
 	// error encountered.
-	fs.Server.Cache.Set("disk_used", size, time.Second*60)
+	fs.Server.cache.Set("disk_used", size, time.Second*60)
 
-	// Determine if their folder size, in bytes, is smaller than the amount of space they've
+	return size, err
-	// been allocated.
-	fs.Server.Resources.Disk = size
-
-	return (size / 1000.0 / 1000.0) <= space
 }
 
 // Determines the directory size of a given location by running parallel tasks to iterate
 // through all of the folders. Returns the size in bytes. This can be a fairly taxing operation
 // on locations with tons of files, so it is recommended that you cache the output.
 func (fs *Filesystem) DirectorySize(dir string) (int64, error) {
-	w := fs.NewWalker()
-	ctx := context.Background()
-
 	var size int64
-	err := w.Walk(dir, ctx, func(f os.FileInfo, _ string) bool {
+	err := fs.Walk(dir, func(_ string, f os.FileInfo, err error) error {
-		// Only increment the size when we're dealing with a file specifically, otherwise
+		if err != nil {
-		// just continue digging deeper until there are no more directories to iterate over.
+			return fs.handleWalkerError(err, f)
+		}
+
 		if !f.IsDir() {
 			atomic.AddInt64(&size, f.Size())
 		}
-		return true
+
+		return nil
 	})
 
 	return size, err
@@ -293,7 +358,7 @@ func (fs *Filesystem) Writefile(p string, r io.Reader) error {
 
 	// Finally, chown the file to ensure the permissions don't end up out-of-whack
 	// if we had just created it.
-	return fs.Chown(p)
+	return fs.Chown(cleaned)
 }
 
 // Defines the stat struct object.
@@ -409,7 +474,7 @@ func (fs *Filesystem) Chown(path string) error {
 	if s, err := os.Stat(cleaned); err != nil {
 		return errors.WithStack(err)
 	} else if !s.IsDir() {
-		return os.Chown(cleaned, fs.Configuration.User.Uid, fs.Configuration.User.Gid)
+		return os.Chown(cleaned, config.Get().System.User.Uid, config.Get().System.User.Gid)
 	}
 
 	return fs.chownDirectory(cleaned)
@@ -435,16 +500,27 @@ func (fs *Filesystem) chownDirectory(path string) error {
 	}
 
 	for _, f := range files {
+		// Do not attempt to chmod a symlink. Go's os.Chown function will affect the symlink
+		// so if it points to a location outside the data directory the user would be able to
+		// (un)intentionally modify that files permissions.
+		if f.Mode()&os.ModeSymlink != 0 {
+			continue
+		}
+
+		p, err := fs.SafeJoin(cleaned, f)
+		if err != nil {
+			return err
+		}
+
 		if f.IsDir() {
 			wg.Add(1)
 
 			go func(p string) {
 				defer wg.Done()
 				fs.chownDirectory(p)
-			}(filepath.Join(cleaned, f.Name()))
+			}(p)
 		} else {
-			// Chown the file.
+			os.Chown(p, config.Get().System.User.Uid, config.Get().System.User.Gid)
-			os.Chown(filepath.Join(cleaned, f.Name()), fs.Configuration.User.Uid, fs.Configuration.User.Gid)
 		}
 	}
 
@@ -536,17 +612,26 @@ func (fs *Filesystem) Copy(p string) error {
 // Deletes a file or folder from the system. Prevents the user from accidentally
 // (or maliciously) removing their root server data directory.
 func (fs *Filesystem) Delete(p string) error {
-	cleaned, err := fs.SafePath(p)
+	// This is one of the few (only?) places in the codebase where we're explictly not using
-	if err != nil {
+	// the SafePath functionality when working with user provided input. If we did, you would
-		return errors.WithStack(err)
+	// not be able to delete a file that is a symlink pointing to a location outside of the data
+	// directory.
+	//
+	// We also want to avoid resolving a symlink that points _within_ the data directory and thus
+	// deleting the actual source file for the symlink rather than the symlink itself. For these
+	// purposes just resolve the actual file path using filepath.Join() and confirm that the path
+	// exists within the data directory.
+	resolved := fs.unsafeFilePath(p)
+	if !fs.unsafeIsInDataDirectory(resolved) {
+		return PathResolutionError{}
 	}
 
 	// Block any whoopsies.
-	if cleaned == fs.Path() {
+	if resolved == fs.Path() {
 		return errors.New("cannot delete root server directory")
 	}
 
-	return os.RemoveAll(cleaned)
+	return os.RemoveAll(resolved)
 }
 
 // Lists the contents of a given directory and returns stat information about each
@@ -579,7 +664,14 @@ func (fs *Filesystem) ListDirectory(p string) ([]*Stat, error) {
 
 			var m = "inode/directory"
 			if !f.IsDir() {
+				cleanedp, _ := fs.SafeJoin(cleaned, f)
+				if cleanedp != "" {
 					m, _, _ = mimetype.DetectFile(filepath.Join(cleaned, f.Name()))
+				} else {
+					// Just pass this for an unknown type because the file could not safely be resolved within
+					// the server data path.
+					m = "application/octet-stream"
+				}
 			}
 
 			out[idx] = &Stat{
@@ -636,9 +728,6 @@ func (fs *Filesystem) GetIncludedFiles(dir string, ignored []string) (*backup.In
 		return nil, err
 	}
 
-	w := fs.NewWalker()
-	ctx := context.Background()
-
 	i, err := ignore.CompileIgnoreLines(ignored...)
 	if err != nil {
 		return nil, err
@@ -647,7 +736,12 @@ func (fs *Filesystem) GetIncludedFiles(dir string, ignored []string) (*backup.In
 	// Walk through all of the files and directories on a server. This callback only returns
 	// files found, and will keep walking deeper and deeper into directories.
 	inc := new(backup.IncludedFiles)
-	if err := w.Walk(cleaned, ctx, func(f os.FileInfo, p string) bool {
+
+	if err := fs.Walk(cleaned, func(p string, f os.FileInfo, err error) error {
+		if err != nil {
+			return fs.handleWalkerError(err, f)
+		}
+
 		// Avoid unnecessary parsing if there are no ignored files, nothing will match anyways
 		// so no reason to call the function.
 		if len(ignored) == 0 || !i.MatchesPath(strings.TrimPrefix(p, fs.Path()+"/")) {
@@ -657,7 +751,7 @@ func (fs *Filesystem) GetIncludedFiles(dir string, ignored []string) (*backup.In
 		// We can't just abort if the path is technically ignored. It is possible there is a nested
 		// file or folder that should not be excluded, so in this case we need to just keep going
 		// until we get to a final state.
-		return true
+		return nil
 	}); err != nil {
 		return nil, err
 	}
@@ -665,7 +759,7 @@ func (fs *Filesystem) GetIncludedFiles(dir string, ignored []string) (*backup.In
 	return inc, nil
 }
 
-// Compresses all of the files matching the given paths in the specififed directory. This function
+// Compresses all of the files matching the given paths in the specified directory. This function
 // also supports passing nested paths to only compress certain files and folders when working in
 // a larger directory. This effectively creates a local backup, but rather than ignoring specific
 // files and folders, it takes an allow-list of files and folders.
@@ -688,42 +782,37 @@ func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, er
 		return nil, err
 	}
 
-	w := fs.NewWalker()
-	wg := new(sync.WaitGroup)
-
 	inc := new(backup.IncludedFiles)
 	// Iterate over all of the cleaned paths and merge them into a large object of final file
 	// paths to pass into the archiver. As directories are encountered this will drop into them
 	// and look for all of the files.
 	for _, p := range cleaned {
-		wg.Add(1)
+		f, err := os.Stat(p)
-
-		go func(pa string) {
-			defer wg.Done()
-
-			f, err := os.Stat(pa)
 		if err != nil {
-				fs.Server.Log().WithField("error", err).WithField("path", pa).Warn("failed to stat file or directory for compression")
+			fs.Server.Log().WithField("error", err).WithField("path", p).Debug("failed to stat file or directory for compression")
-				return
+			continue
 		}
 
 		if f.IsDir() {
-				// Recursively drop into directory and get all of the additional files and directories within
+			err := fs.Walk(p, func(s string, info os.FileInfo, err error) error {
-				// it that should be included in this backup.
+				if err != nil {
-				w.Walk(pa, context.Background(), func(info os.FileInfo, s string) bool {
+					return fs.handleWalkerError(err, info)
+				}
+
 				if !info.IsDir() {
 					inc.Push(&info, s)
 				}
 
-					return true
+				return nil
 			})
-			} else {
-				inc.Push(&f, pa)
-			}
-		}(p)
-	}
 
-	wg.Wait()
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			inc.Push(&f, p)
+		}
+	}
 
 	a := &backup.Archive{TrimPrefix: fs.Path(), Files: inc}
 
@@ -731,3 +820,20 @@ func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, er
 
 	return a.Create(d, context.Background())
 }
+
+// Handle errors encountered when walking through directories.
+//
+// If there is a path resolution error just skip the item entirely. Only return this for a
+// directory, otherwise return nil. Returning this error for a file will stop the walking
+// for the remainder of the directory. This is assuming an os.FileInfo struct was even returned.
+func (fs *Filesystem) handleWalkerError(err error, f os.FileInfo) error {
+	if !IsPathResolutionError(err) {
+		return err
+	}
+
+	if f != nil && f.IsDir() {
+		return filepath.SkipDir
+	}
+
+	return nil
+}

server/filesystem_unarchive.go

@@ -0,0 +1,130 @@
+package server
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"fmt"
+	"github.com/mholt/archiver/v3"
+	"github.com/pkg/errors"
+	"io"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"sync"
+	"sync/atomic"
+)
+
+// Look through a given archive and determine if decompressing it would put the server over
+// its allocated disk space limit.
+func (fs *Filesystem) SpaceAvailableForDecompression(dir string, file string) (bool, error) {
+	// Don't waste time trying to determine this if we know the server will have the space for
+	// it since there is no limit.
+	if fs.Server.Build().DiskSpace <= 0 {
+		return true, nil
+	}
+
+	source, err := fs.SafePath(filepath.Join(dir, file))
+	if err != nil {
+		return false, err
+	}
+
+	wg := new(sync.WaitGroup)
+
+	var dirSize int64
+	var cErr error
+	// Get the cached size in a parallel process so that if it is not cached we are not
+	// waiting an unnecessary amount of time on this call.
+	go func() {
+		wg.Add(1)
+		defer wg.Done()
+
+		dirSize, cErr = fs.getCachedDiskUsage()
+	}()
+
+	var size int64
+	// In a seperate thread, walk over the archive and figure out just how large the final
+	// output would be from dearchiving it.
+	go func() {
+		wg.Add(1)
+		defer wg.Done()
+
+		// Walk all of the files and calculate the total decompressed size of this archive.
+		archiver.Walk(source, func(f archiver.File) error {
+			atomic.AddInt64(&size, f.Size())
+
+			return nil
+		})
+	}()
+
+	wg.Wait()
+
+	return ((dirSize + size) / 1000.0 / 1000.0) <= fs.Server.Build().DiskSpace, cErr
+}
+
+// Decompress a file in a given directory by using the archiver tool to infer the file
+// type and go from there. This will walk over all of the files within the given archive
+// and ensure that there is not a zip-slip attack being attempted by validating that the
+// final path is within the server data directory.
+func (fs *Filesystem) DecompressFile(dir string, file string) error {
+	source, err := fs.SafePath(filepath.Join(dir, file))
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	// Walk over all of the files spinning up an additional go-routine for each file we've encountered
+	// and then extract that file from the archive and write it to the disk. If any part of this process
+	// encounters an error the entire process will be stopped.
+	return archiver.Walk(source, func(f archiver.File) error {
+		// Don't waste time with directories, we don't need to create them if they have no contents, and
+		// we will ensure the directory exists when opening the file for writing anyways.
+		if f.IsDir() {
+			return nil
+		}
+
+		return fs.extractFileFromArchive(f)
+	})
+}
+
+// Extracts a single file from the archive and writes it to the disk after verifying that it will end
+// up in the server data directory.
+func (fs *Filesystem) extractFileFromArchive(f archiver.File) error {
+	var name string
+
+	switch s := f.Sys().(type) {
+	case *tar.Header:
+		name = s.Name
+	case *gzip.Header:
+		name = s.Name
+	case *zip.FileHeader:
+		name = s.Name
+	default:
+		return errors.New(fmt.Sprintf("could not parse underlying data source with type %s", reflect.TypeOf(s).String()))
+	}
+
+	// Guard against a zip-slip attack and prevent writing a file to a destination outside of
+	// the server root directory.
+	p, err := fs.SafePath(name)
+	if err != nil {
+		return err
+	}
+
+	// Ensure the directory structure for this file exists before trying to write the file
+	// to the disk, otherwise we'll have some unexpected fun.
+	if err := os.MkdirAll(strings.TrimSuffix(p, filepath.Base(p)), 0755); err != nil {
+		return err
+	}
+
+	// Open the file and truncate it if it already exists.
+	o, err := os.OpenFile(p, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
+	if err != nil {
+		return err
+	}
+
+	defer o.Close()
+
+	_, cerr := io.Copy(o, f)
+
+	return cerr
+}

server/filesystem_walker.go

@@ -2,69 +2,140 @@ package server
 
 import (
 	"context"
-	"golang.org/x/sync/errgroup"
+	"github.com/gammazero/workerpool"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime"
+	"sync"
 )
 
 type FileWalker struct {
 	*Filesystem
 }
 
+type PooledFileWalker struct {
+	wg       sync.WaitGroup
+	pool     *workerpool.WorkerPool
+	callback filepath.WalkFunc
+	cancel   context.CancelFunc
+
+	err     error
+	errOnce sync.Once
+
+	Filesystem *Filesystem
+}
+
 // Returns a new walker instance.
 func (fs *Filesystem) NewWalker() *FileWalker {
 	return &FileWalker{fs}
 }
 
-// Iterate over all of the files and directories within a given directory. When a file is
+// Creates a new pooled file walker that will concurrently walk over a given directory but limit itself
-// found the callback will be called with the file information. If a directory is encountered
+// to a worker pool as to not completely flood out the system or cause a process crash.
-// it will be recursively passed back through to this function.
+func newPooledWalker(fs *Filesystem) *PooledFileWalker {
-func (fw *FileWalker) Walk(dir string, ctx context.Context, callback func (os.FileInfo, string) bool) error {
+	return &PooledFileWalker{
-	cleaned, err := fw.SafePath(dir)
+		Filesystem: fs,
+		// Create a worker pool that is the same size as the number of processors available on the
+		// system. Going much higher doesn't provide much of a performance boost, and is only more
+		// likely to lead to resource overloading anyways.
+		pool: workerpool.New(runtime.GOMAXPROCS(0)),
+	}
+}
+
+// Process a given path by calling the callback function for all of the files and directories within
+// the path, and then dropping into any directories that we come across.
+func (w *PooledFileWalker) process(path string) error {
+	p, err := w.Filesystem.SafePath(path)
 	if err != nil {
 		return err
 	}
 
-	// Get all of the files from this directory.
+	files, err := ioutil.ReadDir(p)
-	files, err := ioutil.ReadDir(cleaned)
 	if err != nil {
 		return err
 	}
 
-	// Create an error group that we can use to run processes in parallel while retaining
+	// Loop over all of the files and directories in the given directory and call the provided
-	// the ability to cancel the entire process immediately should any of it fail.
+	// callback function. If we encounter a directory, push that directory onto the worker queue
-	g, ctx := errgroup.WithContext(ctx)
+	// to be processed.
-
 	for _, f := range files {
-		if f.IsDir() {
+		sp, err := w.Filesystem.SafeJoin(p, f)
-			fi := f
+		if err != nil {
-			p := filepath.Join(cleaned, f.Name())
+			// Let the callback function handle what to do if there is a path resolution error because a
-			// Recursively call this function to continue digging through the directory tree within
+			// dangerous path was resolved. If there is an error returned, return from this entire process
-			// a seperate goroutine. If the context is canceled abort this process.
+			// otherwise just skip over this specific file. We don't care if its a file or a directory at
-			g.Go(func() error {
+			// this point since either way we're skipping it, however, still check for the SkipDir since that
-				select {
+			// would be thrown otherwise.
-				case <-ctx.Done():
+			if err = w.callback(sp, f, err); err != nil && err != filepath.SkipDir {
-					return ctx.Err()
+				return err
-				default:
+			}
-					// If the callback returns true, go ahead and keep walking deeper. This allows
+
-					// us to programatically continue deeper into directories, or stop digging
+			continue
-					// if that pathway knows it needs nothing else.
+		}
-					if callback(fi, p) {
+
-						return fw.Walk(p, ctx, callback)
+		i, err := os.Stat(sp)
+		// You might end up getting an error about a file or folder not existing if the given path
+		// if it is an invalid symlink. We can safely just skip over these files I believe.
+		if os.IsNotExist(err) {
+			continue
+		}
+
+		// Call the user-provided callback for this file or directory. If an error is returned that is
+		// not a SkipDir call, abort the entire process and bubble that error up.
+		if err = w.callback(sp, i, err); err != nil && err != filepath.SkipDir {
+			return err
+		}
+
+		// If this is a directory, and we didn't get a SkipDir error, continue through by pushing another
+		// job to the pool to handle it. If we requested a skip, don't do anything just continue on to the
+		// next item.
+		if i.IsDir() && err != filepath.SkipDir {
+			w.push(sp)
+		} else if !i.IsDir() && err == filepath.SkipDir {
+			// Per the spec for the callback, if we get a SkipDir error but it is returned for an item
+			// that is _not_ a directory, abort the remaining operations on the directory.
+			return nil
+		}
 	}
 
 	return nil
 }
-			})
+
-		} else {
+// Push a new path into the worker pool and increment the waitgroup so that we do not return too
-			// If this isn't a directory, go ahead and pass the file information into the
+// early and cause panic's as internal directories attempt to submit to the pool.
-			// callback. We don't care about the response since we won't be stepping into
+func (w *PooledFileWalker) push(path string) {
-			// anything from here.
+	w.wg.Add(1)
-			callback(f, filepath.Join(cleaned, f.Name()))
+	w.pool.Submit(func() {
+		defer w.wg.Done()
+		if err := w.process(path); err != nil {
+			w.errOnce.Do(func() {
+				w.err = err
+				if w.cancel != nil {
+					w.cancel()
 				}
+			})
+		}
+	})
 }
 
-	// Block until all of the routines finish and have returned a value.
+// Walks the given directory and executes the callback function for all of the files and directories
-	return g.Wait()
+// that are encountered.
+func (fs *Filesystem) Walk(dir string, callback filepath.WalkFunc) error {
+	w := newPooledWalker(fs)
+	w.callback = callback
+
+	_, cancel := context.WithCancel(context.Background())
+	w.cancel = cancel
+
+	w.push(dir)
+
+	w.wg.Wait()
+	w.pool.StopWait()
+
+	if w.err != nil {
+		return w.err
+	}
+
+	return nil
 }

server/install.go

@@ -36,6 +36,9 @@ func (s *Server) Install(sync bool) error {
 		}
 	}
 
+	// Send the start event so the Panel can automatically update.
+	s.Events().Publish(InstallStartedEvent, "")
+
 	err := s.internalInstall()
 
 	s.Log().Debug("notifying panel of server install state")
@@ -52,6 +55,10 @@ func (s *Server) Install(sync bool) error {
 		l.Warn("failed to notify panel of server install state")
 	}
 
+	// Push an event to the websocket so we can auto-refresh the information in the panel once
+	// the install is completed.
+	s.Events().Publish(InstallCompletedEvent, "")
+
 	return err
 }
 
@@ -70,7 +77,7 @@ func (s *Server) Reinstall() error {
 
 // Internal installation function used to simplify reporting back to the Panel.
 func (s *Server) internalInstall() error {
-	script, rerr, err := api.NewRequester().GetInstallationScript(s.Uuid)
+	script, rerr, err := api.NewRequester().GetInstallationScript(s.Id())
 	if err != nil || rerr != nil {
 		if err != nil {
 			return err
@@ -170,7 +177,7 @@ func (s *Server) AbortInstallation() {
 
 // Removes the installer container for the server.
 func (ip *InstallationProcess) RemoveContainer() {
-	err := ip.client.ContainerRemove(ip.context, ip.Server.Uuid+"_installer", types.ContainerRemoveOptions{
+	err := ip.client.ContainerRemove(ip.context, ip.Server.Id()+"_installer", types.ContainerRemoveOptions{
 		RemoveVolumes: true,
 		Force:         true,
 	})
@@ -313,7 +320,7 @@ func (ip *InstallationProcess) BeforeExecute() (string, error) {
 			Force:         true,
 		}
 
-		if err := ip.client.ContainerRemove(ip.context, ip.Server.Uuid+"_installer", opts); err != nil {
+		if err := ip.client.ContainerRemove(ip.context, ip.Server.Id()+"_installer", opts); err != nil {
 			if !client.IsErrNotFound(err) {
 				e = append(e, err)
 			}
@@ -333,7 +340,7 @@ func (ip *InstallationProcess) BeforeExecute() (string, error) {
 
 // Returns the log path for the installation process.
 func (ip *InstallationProcess) GetLogPath() string {
-	return filepath.Join(config.Get().System.GetInstallLogPath(), ip.Server.Uuid+".log")
+	return filepath.Join(config.Get().System.GetInstallLogPath(), ip.Server.Id()+".log")
 }
 
 // Cleans up after the execution of the installation process. This grabs the logs from the
@@ -369,7 +376,7 @@ func (ip *InstallationProcess) AfterExecute(containerId string) error {
 |
 | Details
 | ------------------------------
-  Server UUID:          {{.Server.Uuid}}
+  Server UUID:          {{.Server.Id}}
   Container Image:      {{.Script.ContainerImage}}
   Container Entrypoint: {{.Script.Entrypoint}}
 
@@ -448,7 +455,7 @@ func (ip *InstallationProcess) Execute(installPath string) (string, error) {
 	}
 
 	ip.Server.Log().WithField("install_script", installPath+"/install.sh").Info("creating install container for server process")
-	r, err := ip.client.ContainerCreate(ip.context, conf, hostConf, nil, ip.Server.Uuid+"_installer")
+	r, err := ip.client.ContainerCreate(ip.context, conf, hostConf, nil, ip.Server.Id()+"_installer")
 	if err != nil {
 		return "", errors.WithStack(err)
 	}
@@ -516,7 +523,7 @@ func (ip *InstallationProcess) StreamOutput(id string) error {
 func (s *Server) SyncInstallState(successful bool) error {
 	r := api.NewRequester()
 
-	rerr, err := r.SendInstallationStatus(s.Uuid, successful)
+	rerr, err := r.SendInstallationStatus(s.Id(), successful)
 	if rerr != nil || err != nil {
 		if err != nil {
 			return errors.WithStack(err)

server/listeners.go

@@ -27,9 +27,11 @@ func (s *Server) onConsoleOutput(data string) {
 	// If the specific line of output is one that would mark the server as started,
 	// set the server to that state. Only do this if the server is not currently stopped
 	// or stopping.
-	if s.GetState() == ProcessStartingState && strings.Contains(data, s.processConfiguration.Startup.Done) {
+	match := s.ProcessConfiguration().Startup.Done
+
+	if s.GetState() == ProcessStartingState && strings.Contains(data, match) {
 		s.Log().WithFields(log.Fields{
-			"match": s.processConfiguration.Startup.Done,
+			"match": match,
 			"against": data,
 		}).Debug("detected server in running state based on console line output")
 
@@ -40,7 +42,8 @@ func (s *Server) onConsoleOutput(data string) {
 	// set the server to be in a stopping state, otherwise crash detection will kick in and
 	// cause the server to unexpectedly restart on the user.
 	if s.IsRunning() {
-		if s.processConfiguration.Stop.Type == api.ProcessStopCommand && data == s.processConfiguration.Stop.Value {
+		stop := s.ProcessConfiguration().Stop
+		if stop.Type == api.ProcessStopCommand && data == stop.Value {
 			s.SetState(ProcessStoppingState)
 		}
 	}

server/loader.go

@@ -0,0 +1,120 @@
+package server
+
+import (
+	"github.com/apex/log"
+	"github.com/creasty/defaults"
+	"github.com/patrickmn/go-cache"
+	"github.com/pkg/errors"
+	"github.com/pterodactyl/wings/api"
+	"github.com/remeh/sizedwaitgroup"
+	"time"
+)
+
+var servers = NewCollection(nil)
+
+func GetServers() *Collection {
+	return servers
+}
+
+// Iterates over a given directory and loads all of the servers listed before returning
+// them to the calling function.
+func LoadDirectory() error {
+	if len(servers.items) != 0 {
+		return errors.New("cannot call LoadDirectory with a non-nil collection")
+	}
+
+	// We could theoretically use a standard wait group here, however doing
+	// that introduces the potential to crash the program due to too many
+	// open files. This wouldn't happen on a small setup, but once the daemon is
+	// handling many servers you run that risk.
+	//
+	// For now just process 10 files at a time, that should be plenty fast to
+	// read and parse the YAML. We should probably make this configurable down
+	// the road to help big instances scale better.
+	wg := sizedwaitgroup.New(10)
+
+	configs, rerr, err := api.NewRequester().GetAllServerConfigurations()
+	if err != nil || rerr != nil {
+		if err != nil {
+			return errors.WithStack(err)
+		}
+
+		return errors.New(rerr.String())
+	}
+
+	log.Debug("retrieving cached server states from disk")
+	states, err := getServerStates()
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	log.WithField("total_configs", len(configs)).Debug("looping over received configurations from API")
+	for uuid, data := range configs {
+		wg.Add()
+
+		go func(uuid string, data *api.ServerConfigurationResponse) {
+			defer wg.Done()
+
+			log.WithField("uuid", uuid).Debug("creating server object from configuration")
+			s, err := FromConfiguration(data)
+			if err != nil {
+				log.WithField("server", uuid).WithField("error", err).Error("failed to load server, skipping...")
+				return
+			}
+
+			if state, exists := states[s.Id()]; exists {
+				s.SetState(state)
+				s.Log().WithField("state", s.GetState()).Debug("loaded server state from cache file")
+			}
+
+			servers.Add(s)
+		}(uuid, data)
+	}
+
+	// Wait until we've processed all of the configuration files in the directory
+	// before continuing.
+	wg.Wait()
+
+	return nil
+}
+
+// Initializes a server using a data byte array. This will be marshaled into the
+// given struct using a YAML marshaler. This will also configure the given environment
+// for a server.
+func FromConfiguration(data *api.ServerConfigurationResponse) (*Server, error) {
+	cfg := Configuration{}
+	if err := defaults.Set(&cfg); err != nil {
+		return nil, err
+	}
+
+	s := new(Server)
+	s.cfg = cfg
+
+	if err := s.UpdateDataStructure(data.Settings, false); err != nil {
+		return nil, err
+	}
+
+	s.AddEventListeners()
+
+	// Right now we only support a Docker based environment, so I'm going to hard code
+	// this logic in. When we're ready to support other environment we'll need to make
+	// some modifications here obviously.
+	if err := NewDockerEnvironment(s); err != nil {
+		return nil, err
+	}
+
+	s.cache = cache.New(time.Minute*10, time.Minute*15)
+	s.Archiver = Archiver{
+		Server: s,
+	}
+	s.Filesystem = Filesystem{
+		Server:        s,
+	}
+
+	// Forces the configuration to be synced with the panel.
+	if err := s.SyncWithConfiguration(data); err != nil {
+		return nil, err
+	}
+
+	return s, nil
+}

server/process.go

@@ -0,0 +1,10 @@
+package server
+
+import "github.com/pterodactyl/wings/api"
+
+func (s *Server) ProcessConfiguration() *api.ProcessConfiguration {
+	s.RLock()
+	defer s.RUnlock()
+
+	return s.procConfig
+}

server/resources.go

@@ -3,27 +3,38 @@ package server
 import (
 	"github.com/docker/docker/api/types"
 	"math"
+	"sync"
+	"sync/atomic"
 )
 
 // Defines the current resource usage for a given server instance. If a server is offline you
 // should obviously expect memory and CPU usage to be 0. However, disk will always be returned
 // since that is not dependent on the server being running to collect that data.
 type ResourceUsage struct {
+	mu sync.RWMutex
+
+	// The current server status.
+	State string `json:"state" default:"offline"`
+
 	// The total amount of memory, in bytes, that this server instance is consuming. This is
 	// calculated slightly differently than just using the raw Memory field that the stats
 	// return from the container, so please check the code setting this value for how that
 	// is calculated.
 	Memory uint64 `json:"memory_bytes"`
+
 	// The total amount of memory this container or resource can use. Inside Docker this is
 	// going to be higher than you'd expect because we're automatically allocating overhead
 	// abilities for the container, so its not going to be a perfect match.
 	MemoryLimit uint64 `json:"memory_limit_bytes"`
+
 	// The absolute CPU usage is the amount of CPU used in relation to the entire system and
 	// does not take into account any limits on the server process itself.
 	CpuAbsolute float64 `json:"cpu_absolute"`
+
 	// The current disk space being used by the server. This is cached to prevent slow lookup
 	// issues on frequent refreshes.
 	Disk int64 `json:"disk_bytes"`
+
 	// Current network transmit in & out for a container.
 	Network struct {
 		RxBytes uint64 `json:"rx_bytes"`
@@ -31,6 +42,66 @@ type ResourceUsage struct {
 	} `json:"network"`
 }
 
+// Returns the resource usage stats for the server instance. If the server is not running, only the
+// disk space currently used will be returned. When the server is running all of the other stats will
+// be returned.
+//
+// When a process is stopped all of the stats are zeroed out except for the disk.
+func (s *Server) Proc() *ResourceUsage {
+	s.resources.mu.RLock()
+	defer s.resources.mu.RUnlock()
+
+	return &s.resources
+}
+
+// Returns the servers current state.
+func (ru *ResourceUsage) getInternalState() string {
+	ru.mu.RLock()
+	defer ru.mu.RUnlock()
+
+	return ru.State
+}
+
+// Sets the new state for the server.
+func (ru *ResourceUsage) setInternalState(state string) {
+	ru.mu.Lock()
+	ru.State = state
+	ru.mu.Unlock()
+}
+
+// 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) Empty() {
+	ru.mu.Lock()
+	defer ru.mu.Unlock()
+
+	ru.Memory = 0
+	ru.CpuAbsolute = 0
+	ru.Network.TxBytes = 0
+	ru.Network.RxBytes = 0
+}
+
+func (ru *ResourceUsage) SetDisk(i int64) {
+	ru.mu.Lock()
+	defer ru.mu.Unlock()
+
+	ru.Disk = i
+}
+
+func (ru *ResourceUsage) UpdateFromDocker(v *types.StatsJSON) {
+	ru.mu.Lock()
+	defer ru.mu.Unlock()
+
+	ru.CpuAbsolute = ru.calculateDockerAbsoluteCpu(&v.PreCPUStats, &v.CPUStats)
+	ru.Memory = ru.calculateDockerMemory(v.MemoryStats)
+	ru.MemoryLimit = v.MemoryStats.Limit
+}
+
+func (ru *ResourceUsage) UpdateNetworkBytes(nw *types.NetworkStats) {
+	atomic.AddUint64(&ru.Network.RxBytes, nw.RxBytes)
+	atomic.AddUint64(&ru.Network.TxBytes, nw.TxBytes)
+}
+
 // The "docker stats" CLI call does not return the same value as the types.MemoryStats.Usage
 // value which can be rather confusing to people trying to compare panel usage to
 // their stats output.
@@ -40,7 +111,7 @@ type ResourceUsage struct {
 // correct memory value anyways.
 //
 // @see https://github.com/docker/cli/blob/96e1d1d6/cli/command/container/stats_helpers.go#L227-L249
-func (ru *ResourceUsage) CalculateDockerMemory(stats types.MemoryStats) uint64 {
+func (ru *ResourceUsage) calculateDockerMemory(stats types.MemoryStats) uint64 {
 	if v, ok := stats.Stats["total_inactive_file"]; ok && v < stats.Usage {
 		return stats.Usage - v
 	}
@@ -56,7 +127,7 @@ func (ru *ResourceUsage) CalculateDockerMemory(stats types.MemoryStats) uint64 {
 // by the defined CPU limits on the container.
 //
 // @see https://github.com/docker/cli/blob/aa097cf1aa19099da70930460250797c8920b709/cli/command/container/stats_helpers.go#L166
-func (ru *ResourceUsage) CalculateAbsoluteCpu(pStats *types.CPUStats, stats *types.CPUStats) float64 {
+func (ru *ResourceUsage) calculateDockerAbsoluteCpu(pStats *types.CPUStats, stats *types.CPUStats) float64 {
 	// Calculate the change in CPU usage between the current and previous reading.
 	cpuDelta := float64(stats.CPUUsage.TotalUsage) - float64(pStats.CPUUsage.TotalUsage)
 

server/server.go

@@ -4,99 +4,38 @@ import (
 	"context"
 	"fmt"
 	"github.com/apex/log"
-	"github.com/creasty/defaults"
 	"github.com/patrickmn/go-cache"
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/api"
-	"github.com/pterodactyl/wings/config"
-	"github.com/remeh/sizedwaitgroup"
 	"golang.org/x/sync/semaphore"
-	"math"
 	"os"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
 )
 
-var servers *Collection
-
-func GetServers() *Collection {
-	return servers
-}
-
-type EnvironmentVariables map[string]interface{}
-
-// Ugly hacky function to handle environment variables that get passed through as not-a-string
-// from the Panel. Ideally we'd just say only pass strings, but that is a fragile idea and if a
-// string wasn't passed through you'd cause a crash or the server to become unavailable. For now
-// try to handle the most likely values from the JSON and hope for the best.
-func (ev EnvironmentVariables) Get(key string) string {
-	val, ok := ev[key]
-	if !ok {
-		return ""
-	}
-
-	switch val.(type) {
-	case int:
-		return strconv.Itoa(val.(int))
-	case int32:
-		return strconv.FormatInt(val.(int64), 10)
-	case int64:
-		return strconv.FormatInt(val.(int64), 10)
-	case float32:
-		return fmt.Sprintf("%f", val.(float32))
-	case float64:
-		return fmt.Sprintf("%f", val.(float64))
-	case bool:
-		return strconv.FormatBool(val.(bool))
-	}
-
-	return val.(string)
-}
-
 // High level definition for a server instance being controlled by Wings.
 type Server struct {
-	// The unique identifier for the server that should be used when referencing
+	// Internal mutex used to block actions that need to occur sequentially, such as
-	// it against the Panel API (and internally). This will be used when naming
+	// writing the configuration to the disk.
-	// docker containers as well as in log output.
+	sync.RWMutex
-	Uuid string `json:"uuid"`
+	emitterLock sync.Mutex
 
-	// Whether or not the server is in a suspended state. Suspended servers cannot
+	// Maintains the configuration for the server. This is the data that gets returned by the Panel
-	// be started or modified except in certain scenarios by an admin user.
+	// such as build settings and container images.
-	Suspended bool `json:"suspended"`
+	cfg Configuration
 
-	// The power state of the server.
+	// The crash handler for this server instance.
-	State string `default:"offline" json:"state"`
+	crasher CrashHandler
-
-	// The command that should be used when booting up the server instance.
-	Invocation string `json:"invocation"`
-
-	// An array of environment variables that should be passed along to the running
-	// server process.
-	EnvVars EnvironmentVariables `json:"environment"`
-
-	Allocations    Allocations    `json:"allocations"`
-	Build          BuildSettings  `json:"build"`
-	CrashDetection CrashDetection `json:"crash_detection"`
-	Mounts         []Mount        `json:"mounts"`
-	Resources      ResourceUsage  `json:"resources"`
 
+	resources   ResourceUsage
 	Archiver    Archiver    `json:"-"`
 	Environment Environment `json:"-"`
 	Filesystem  Filesystem  `json:"-"`
 
-	Container struct {
-		// Defines the Docker image that will be used for this server
-		Image string `json:"image,omitempty"`
-		// If set to true, OOM killer will be disabled on the server's Docker container.
-		// If not present (nil) we will default to disabling it.
-		OomDisabled bool `default:"true" json:"oom_disabled"`
-	} `json:"container,omitempty"`
-
 	// Server cache used to store frequently requested information in memory and make
 	// certain long operations return faster. For example, FS disk space usage.
-	Cache *cache.Cache `json:"-"`
+	cache *cache.Cache
 
 	// Events emitted by the server instance.
 	emitter *EventBus
@@ -104,17 +43,13 @@ type Server struct {
 	// Defines the process configuration for the server instance. This is dynamically
 	// fetched from the Pterodactyl Server instance each time the server process is
 	// started, and then cached here.
-	processConfiguration *api.ProcessConfiguration
+	procConfig *api.ProcessConfiguration
 
 	// Tracks the installation process for this server and prevents a server from running
 	// two installer processes at the same time. This also allows us to cancel a running
 	// installation process, for example when a server is deleted from the panel while the
 	// installer process is still running.
 	installer InstallerDetails
-
-	// Internal mutex used to block actions that need to occur sequentially, such as
-	// writing the configuration to the disk.
-	sync.RWMutex
 }
 
 type InstallerDetails struct {
@@ -127,183 +62,9 @@ type InstallerDetails struct {
 	sem *semaphore.Weighted
 }
 
-// The build settings for a given server that impact docker container creation and
+// Returns the UUID for the server instance.
-// resource limits for a server instance.
+func (s *Server) Id() string {
-type BuildSettings struct {
+	return s.Config().GetUuid()
-	// The total amount of memory in megabytes that this server is allowed to
-	// use on the host system.
-	MemoryLimit int64 `json:"memory_limit"`
-
-	// The amount of additional swap space to be provided to a container instance.
-	Swap int64 `json:"swap"`
-
-	// The relative weight for IO operations in a container. This is relative to other
-	// containers on the system and should be a value between 10 and 1000.
-	IoWeight uint16 `json:"io_weight"`
-
-	// The percentage of CPU that this instance is allowed to consume relative to
-	// the host. A value of 200% represents complete utilization of two cores. This
-	// should be a value between 1 and THREAD_COUNT * 100.
-	CpuLimit int64 `json:"cpu_limit"`
-
-	// The amount of disk space in megabytes that a server is allowed to use.
-	DiskSpace int64 `json:"disk_space"`
-
-	// Sets which CPU threads can be used by the docker instance.
-	Threads string `json:"threads"`
-}
-
-// Converts the CPU limit for a server build into a number that can be better understood
-// by the Docker environment. If there is no limit set, return -1 which will indicate to
-// Docker that it has unlimited CPU quota.
-func (b *BuildSettings) ConvertedCpuLimit() int64 {
-	if b.CpuLimit == 0 {
-		return -1
-	}
-
-	return b.CpuLimit * 1000
-}
-
-// Set the hard limit for memory usage to be 5% more than the amount of memory assigned to
-// the server. If the memory limit for the server is < 4G, use 10%, if less than 2G use
-// 15%. This avoids unexpected crashes from processes like Java which run over the limit.
-func (b *BuildSettings) MemoryOverheadMultiplier() float64 {
-	if b.MemoryLimit <= 2048 {
-		return 1.15
-	} else if b.MemoryLimit <= 4096 {
-		return 1.10
-	}
-
-	return 1.05
-}
-
-func (b *BuildSettings) BoundedMemoryLimit() int64 {
-	return int64(math.Round(float64(b.MemoryLimit) * b.MemoryOverheadMultiplier() * 1_000_000))
-}
-
-// Returns the amount of swap available as a total in bytes. This is returned as the amount
-// of memory available to the server initially, PLUS the amount of additional swap to include
-// which is the format used by Docker.
-func (b *BuildSettings) ConvertedSwap() int64 {
-	if b.Swap < 0 {
-		return -1
-	}
-
-	return (b.Swap * 1_000_000) + b.BoundedMemoryLimit()
-}
-
-// Defines the allocations available for a given server. When using the Docker environment
-// driver these correspond to mappings for the container that allow external connections.
-type Allocations struct {
-	// Defines the default allocation that should be used for this server. This is
-	// what will be used for {SERVER_IP} and {SERVER_PORT} when modifying configuration
-	// files or the startup arguments for a server.
-	DefaultMapping struct {
-		Ip   string `json:"ip"`
-		Port int    `json:"port"`
-	} `json:"default"`
-
-	// Mappings contains all of the ports that should be assigned to a given server
-	// attached to the IP they correspond to.
-	Mappings map[string][]int `json:"mappings"`
-}
-
-// Iterates over a given directory and loads all of the servers listed before returning
-// them to the calling function.
-func LoadDirectory() error {
-	// We could theoretically use a standard wait group here, however doing
-	// that introduces the potential to crash the program due to too many
-	// open files. This wouldn't happen on a small setup, but once the daemon is
-	// handling many servers you run that risk.
-	//
-	// For now just process 10 files at a time, that should be plenty fast to
-	// read and parse the YAML. We should probably make this configurable down
-	// the road to help big instances scale better.
-	wg := sizedwaitgroup.New(10)
-
-	configs, rerr, err := api.NewRequester().GetAllServerConfigurations()
-	if err != nil || rerr != nil {
-		if err != nil {
-			return errors.WithStack(err)
-		}
-
-		return errors.New(rerr.String())
-	}
-
-	states, err := getServerStates()
-	if err != nil {
-		return errors.WithStack(err)
-	}
-
-	servers = NewCollection(nil)
-
-	for uuid, data := range configs {
-		wg.Add()
-
-		go func(uuid string, data *api.ServerConfigurationResponse) {
-			defer wg.Done()
-
-			s, err := FromConfiguration(data)
-			if err != nil {
-				log.WithField("server", uuid).WithField("error", err).Error("failed to load server, skipping...")
-				return
-			}
-
-			if state, exists := states[s.Uuid]; exists {
-				s.SetState(state)
-				s.Log().WithField("state", s.GetState()).Debug("loaded server state from cache file")
-			}
-
-			servers.Add(s)
-		}(uuid, data)
-	}
-
-	// Wait until we've processed all of the configuration files in the directory
-	// before continuing.
-	wg.Wait()
-
-	return nil
-}
-
-// Initializes a server using a data byte array. This will be marshaled into the
-// given struct using a YAML marshaler. This will also configure the given environment
-// for a server.
-func FromConfiguration(data *api.ServerConfigurationResponse) (*Server, error) {
-	s := new(Server)
-
-	if err := defaults.Set(s); err != nil {
-		return nil, err
-	}
-
-	if err := s.UpdateDataStructure(data.Settings, false); err != nil {
-		return nil, err
-	}
-
-	s.AddEventListeners()
-
-	// Right now we only support a Docker based environment, so I'm going to hard code
-	// this logic in. When we're ready to support other environment we'll need to make
-	// some modifications here obviously.
-	if err := NewDockerEnvironment(s); err != nil {
-		return nil, err
-	}
-
-	s.Cache = cache.New(time.Minute*10, time.Minute*15)
-	s.Archiver = Archiver{
-		Server: s,
-	}
-	s.Filesystem = Filesystem{
-		Configuration: &config.Get().System,
-		Server:        s,
-	}
-	s.Resources = ResourceUsage{}
-
-	// Forces the configuration to be synced with the panel.
-	if err := s.SyncWithConfiguration(data); err != nil {
-		return nil, err
-	}
-
-	return s, nil
 }
 
 // Returns all of the environment variables that should be assigned to a running
@@ -313,28 +74,28 @@ func (s *Server) GetEnvironmentVariables() []string {
 
 	var out = []string{
 		fmt.Sprintf("TZ=%s", zone),
-		fmt.Sprintf("STARTUP=%s", s.Invocation),
+		fmt.Sprintf("STARTUP=%s", s.Config().Invocation),
-		fmt.Sprintf("SERVER_MEMORY=%d", s.Build.MemoryLimit),
+		fmt.Sprintf("SERVER_MEMORY=%d", s.Build().MemoryLimit),
-		fmt.Sprintf("SERVER_IP=%s", s.Allocations.DefaultMapping.Ip),
+		fmt.Sprintf("SERVER_IP=%s", s.Config().Allocations.DefaultMapping.Ip),
-		fmt.Sprintf("SERVER_PORT=%d", s.Allocations.DefaultMapping.Port),
+		fmt.Sprintf("SERVER_PORT=%d", s.Config().Allocations.DefaultMapping.Port),
 	}
 
 eloop:
-	for k := range s.EnvVars {
+	for k := range s.Config().EnvVars {
 		for _, e := range out {
 			if strings.HasPrefix(e, strings.ToUpper(k)) {
 				continue eloop
 			}
 		}
 
-		out = append(out, fmt.Sprintf("%s=%s", strings.ToUpper(k), s.EnvVars.Get(k)))
+		out = append(out, fmt.Sprintf("%s=%s", strings.ToUpper(k), s.Config().EnvVars.Get(k)))
 	}
 
 	return out
 }
 
 func (s *Server) Log() *log.Entry {
-	return log.WithField("server", s.Uuid)
+	return log.WithField("server", s.Id())
 }
 
 // Syncs the state of the server on the Panel with Wings. This ensures that we're always
@@ -366,7 +127,10 @@ func (s *Server) SyncWithConfiguration(cfg *api.ServerConfigurationResponse) err
 		return errors.WithStack(err)
 	}
 
-	s.processConfiguration = cfg.ProcessConfiguration
+	s.Lock()
+	s.procConfig = cfg.ProcessConfiguration
+	s.Unlock()
+
 	return nil
 }
 
@@ -391,7 +155,7 @@ func (s *Server) CreateEnvironment() error {
 
 // Gets the process configuration data for the server.
 func (s *Server) GetProcessConfiguration() (*api.ServerConfigurationResponse, *api.RequestError, error) {
-	return api.NewRequester().GetServerConfiguration(s.Uuid)
+	return api.NewRequester().GetServerConfiguration(s.Id())
 }
 
 // Helper function that can receieve a power action and then process the
@@ -401,11 +165,7 @@ func (s *Server) HandlePowerAction(action PowerAction) error {
 	case "start":
 		return s.Environment.Start()
 	case "restart":
-		if err := s.Environment.WaitForStop(60, false); err != nil {
+		return s.Environment.Restart()
-			return err
-		}
-
-		return s.Environment.Start()
 	case "stop":
 		return s.Environment.Stop()
 	case "kill":
@@ -414,3 +174,8 @@ func (s *Server) HandlePowerAction(action PowerAction) error {
 		return errors.New("an invalid power action was provided")
 	}
 }
+
+// Checks if the server is marked as being suspended or not on the system.
+func (s *Server) IsSuspended() bool {
+	return s.Config().Suspended
+}

server/state.go

@@ -13,6 +13,13 @@ import (
 
 var stateMutex sync.Mutex
 
+const (
+	ProcessOfflineState  = "offline"
+	ProcessStartingState = "starting"
+	ProcessRunningState  = "running"
+	ProcessStoppingState = "stopping"
+)
+
 // Returns the state of the servers.
 func getServerStates() (map[string]string, error) {
 	// Request a lock after we check if the file exists.
@@ -40,7 +47,7 @@ func saveServerStates() error {
 	// Get the states of all servers on the daemon.
 	states := map[string]string{}
 	for _, s := range GetServers().All() {
-		states[s.Uuid] = s.GetState()
+		states[s.Id()] = s.GetState()
 	}
 
 	// Convert the map to a json object.
@@ -60,13 +67,6 @@ func saveServerStates() error {
 	return nil
 }
 
-const (
-	ProcessOfflineState  = "offline"
-	ProcessStartingState = "starting"
-	ProcessRunningState  = "running"
-	ProcessStoppingState = "stopping"
-)
-
 // Sets the state of the server internally. This function handles crash detection as
 // well as reporting to event listeners for the server.
 func (s *Server) SetState(state string) error {
@@ -76,16 +76,14 @@ func (s *Server) SetState(state string) error {
 
 	prevState := s.GetState()
 
-	// Obtain a mutex lock and update the current state of the server.
+	// Update the currently tracked state for the server.
-	s.Lock()
+	s.Proc().setInternalState(state)
-	s.State = state
 
 	// Emit the event to any listeners that are currently registered.
-	s.Log().WithField("status", s.State).Debug("saw server status change event")
+	if prevState != state {
-	s.Events().Publish(StatusEvent, s.State)
+		s.Log().WithField("status", s.Proc().State).Debug("saw server status change event")
-
+		s.Events().Publish(StatusEvent, s.Proc().State)
-	// Release the lock as it is no longer needed for the following actions.
+	}
-	s.Unlock()
 
 	// Persist this change to the disk immediately so that should the Daemon be stopped or
 	// crash we can immediately restore the server state.
@@ -128,15 +126,14 @@ func (s *Server) SetState(state string) error {
 
 // Returns the current state of the server in a race-safe manner.
 func (s *Server) GetState() string {
-	s.RLock()
+	return s.Proc().getInternalState()
-	defer s.RUnlock()
-
-	return s.State
 }
 
 // Determines if the server state is running or not. This is different than the
 // environment state, it is simply the tracked state from this daemon instance, and
 // not the response from Docker.
 func (s *Server) IsRunning() bool {
-	return s.GetState() == ProcessRunningState || s.GetState() == ProcessStartingState
+	st := s.GetState()
+
+	return st == ProcessRunningState || st == ProcessStartingState
 }

server/update.go

@@ -15,7 +15,7 @@ import (
 // it is up to the specific environment to determine what needs to happen when
 // that is the case.
 func (s *Server) UpdateDataStructure(data []byte, background bool) error {
-	src := new(Server)
+	src := new(Configuration)
 	if err := json.Unmarshal(data, src); err != nil {
 		return errors.WithStack(err)
 	}
@@ -23,13 +23,29 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 	// Don't allow obviously corrupted data to pass through into this function. If the UUID
 	// doesn't match something has gone wrong and the API is attempting to meld this server
 	// instance into a totally different one, which would be bad.
-	if src.Uuid != "" && s.Uuid != "" && src.Uuid != s.Uuid {
+	if src.Uuid != "" && s.Id() != "" && src.Uuid != s.Id() {
 		return errors.New("attempting to merge a data stack with an invalid UUID")
 	}
 
+	// Grab a copy of the configuration to work on.
+	c := *s.Config()
+
+	// Lock our copy of the configuration since the defered unlock will end up acting upon this
+	// new memory address rather than the old one. If we don't lock this, the defered unlock will
+	// cause a panic when it goes to run. However, since we only update s.cfg at the end, if there
+	// is an error before that point we'll still properly unlock the original configuration for the
+	// server.
+	c.mu.Lock()
+
+	// Lock the server configuration while we're doing this merge to avoid anything
+	// trying to overwrite it or make modifications while we're sorting out what we
+	// need to do.
+	s.cfg.mu.Lock()
+	defer s.cfg.mu.Unlock()
+
 	// Merge the new data object that we have received with the existing server data object
 	// and then save it to the disk so it is persistent.
-	if err := mergo.Merge(s, src, mergo.WithOverride); err != nil {
+	if err := mergo.Merge(&c, src, mergo.WithOverride); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -39,9 +55,9 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 	// backfiring at some point, but until then...
 	//
 	// We'll go ahead and do this with swap as well.
-	s.Build.CpuLimit = src.Build.CpuLimit
+	c.Build.CpuLimit = src.Build.CpuLimit
-	s.Build.Swap = src.Build.Swap
+	c.Build.Swap = src.Build.Swap
-	s.Build.DiskSpace = src.Build.DiskSpace
+	c.Build.DiskSpace = src.Build.DiskSpace
 
 	// Mergo can't quite handle this boolean value correctly, so for now we'll just
 	// handle this edge case manually since none of the other data passed through in this
@@ -51,7 +67,7 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 			return errors.WithStack(err)
 		}
 	} else {
-		s.Container.OomDisabled = v
+		c.Container.OomDisabled = v
 	}
 
 	// Mergo also cannot handle this boolean value.
@@ -60,25 +76,28 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 			return errors.WithStack(err)
 		}
 	} else {
-		s.Suspended = v
+		c.Suspended = v
 	}
 
 	// Environment and Mappings should be treated as a full update at all times, never a
 	// true patch, otherwise we can't know what we're passing along.
 	if src.EnvVars != nil && len(src.EnvVars) > 0 {
-		s.EnvVars = src.EnvVars
+		c.EnvVars = src.EnvVars
 	}
 
 	if src.Allocations.Mappings != nil && len(src.Allocations.Mappings) > 0 {
-		s.Allocations.Mappings = src.Allocations.Mappings
+		c.Allocations.Mappings = src.Allocations.Mappings
 	}
 
 	if src.Mounts != nil && len(src.Mounts) > 0 {
-		s.Mounts = src.Mounts
+		c.Mounts = src.Mounts
 	}
 
+	// Update the configuration once we have a lock on the configuration object.
+	s.cfg = c
+
 	if background {
-		s.runBackgroundActions()
+		go s.runBackgroundActions()
 	}
 
 	return nil
@@ -91,24 +110,22 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 // These tasks run in independent threads where relevant to speed up any updates
 // that need to happen.
 func (s *Server) runBackgroundActions() {
+	// Check if the s is now suspended, and if so and the process is not terminated
+	// yet, do it immediately.
+	if s.IsSuspended() && s.GetState() != ProcessOfflineState {
+		s.Log().Info("server suspended with running process state, terminating now")
+
+		if err := s.Environment.WaitForStop(10, true); err != nil {
+			s.Log().WithField("error", err).Warn("failed to terminate server environment after suspension")
+		}
+	}
+
+	if !s.IsSuspended() {
 		// Update the environment in place, allowing memory and CPU usage to be adjusted
 		// on the fly without the user needing to reboot (theoretically).
-	go func(server *Server) {
+		s.Log().Info("performing server limit modification on-the-fly")
-		server.Log().Info("performing server limit modification on-the-fly")
+		if err := s.Environment.InSituUpdate(); err != nil {
-		if err := server.Environment.InSituUpdate(); err != nil {
+			s.Log().WithField("error", err).Warn("failed to perform on-the-fly update of the server environment")
-			server.Log().WithField("error", err).Warn("failed to perform on-the-fly update of the server environment")
-		}
-	}(s)
-
-	// Check if the server is now suspended, and if so and the process is not terminated
-	// yet, do it immediately.
-	go func(server *Server) {
-		if server.Suspended && server.GetState() != ProcessOfflineState {
-			server.Log().Info("server suspended with running process state, terminating now")
-
-			if err := server.Environment.WaitForStop(10, true); err != nil {
-				server.Log().WithField("error", err).Warn("failed to terminate server environment after suspension")
 		}
 	}
-	}(s)
 }

sftp/server.go

@@ -49,7 +49,7 @@ func Initialize(config *config.Configuration) error {
 
 func validatePath(fs sftp_server.FileSystem, p string) (string, error) {
 	s := server.GetServers().Find(func(server *server.Server) bool {
-		return server.Uuid == fs.UUID
+		return server.Id() == fs.UUID
 	})
 
 	if s == nil {
@@ -61,7 +61,7 @@ func validatePath(fs sftp_server.FileSystem, p string) (string, error) {
 
 func validateDiskSpace(fs sftp_server.FileSystem) bool {
 	s := server.GetServers().Find(func(server *server.Server) bool {
-		return server.Uuid == fs.UUID
+		return server.Id() == fs.UUID
 	})
 
 	if s == nil {
@@ -105,7 +105,7 @@ func validateCredentials(c sftp_server.AuthenticationRequest) (*sftp_server.Auth
 	}
 
 	s := server.GetServers().Find(func(server *server.Server) bool {
-		return server.Uuid == resp.Server
+		return server.Id() == resp.Server
 	})
 
 	if s == nil {