Remove pointless debug log

Fixes deadlocks that occurred when events were registered while other events were being unsubscribed and data was being flooded to these listeners. A complete mess, I hate this code, it is going to break again, but jesus I'm so tired.

.github/workflows/build-test.yml

@@ -17,7 +17,7 @@ jobs:
           go-version: '^1.15'
       
       - name: Build
-        run: GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" -ldflags "-X github.com/pterodactyl/wings/system.Version=dev-${GIT_COMMIT:0:7}" -o build/wings_linux_amd64 -v wings.go
+        run: GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/pterodactyl/wings/system.Version=dev-${GIT_COMMIT:0:7}" -o build/wings_linux_amd64 -v wings.go
       
       - name: Test
         run: go test ./...

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Build
         env:
           REF: ${{ github.ref }}
-        run: GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" -ldflags "-X github.com/pterodactyl/wings/system.Version=${REF:11}" -o build/wings_linux_amd64 -v wings.go
+        run: GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/pterodactyl/wings/system.Version=${REF:11}" -o build/wings_linux_amd64 -v wings.go
       
       - name: Test
         run: go test ./...

config/config_system.go

@@ -36,6 +36,12 @@ type SystemConfiguration struct {
 		Gid int
 	}
 
+	// The amount of time in seconds that can elapse before a server's disk space calculation is
+	// considered stale and a re-check should occur. DANGER: setting this value too low can seriously
+	// impact system performance and cause massive I/O bottlenecks and high CPU usage for the Wings
+	// process.
+	DiskCheckInterval int64 `default:"150" yaml:"disk_check_interval"`
+
 	// Determines if Wings should detect a server that stops with a normal exit code of
 	// "0" as being crashed if the process stopped without any Wings interaction. E.g.
 	// the user did not press the stop button, but the process stopped cleanly.

events/events.go

@@ -47,8 +47,12 @@ func (e *EventBus) Publish(topic string, data string) {
 		defer e.RUnlock()
 
 		if ch, ok := e.subscribers[t]; ok {
+			e := Event{Data: data, Topic: topic}
+
 			for channel := range ch {
-				channel <- Event{Data: data, Topic: topic}
+				go func(channel chan Event, e Event) {
+					channel <- e
+				}(channel, e)
 			}
 		}
 	}()
@@ -66,29 +70,33 @@ func (e *EventBus) PublishJson(topic string, data interface{}) error {
 }
 
 // Subscribe to an emitter topic using a channel.
-func (e *EventBus) Subscribe(topic string, ch chan Event) {
+func (e *EventBus) Subscribe(topics []string, ch chan Event) {
 	e.Lock()
 	defer e.Unlock()
 
-	if _, exists := e.subscribers[topic]; !exists {
-		e.subscribers[topic] = make(map[chan Event]struct{})
-	}
+	for _, topic := range topics {
+		if _, exists := e.subscribers[topic]; !exists {
+			e.subscribers[topic] = make(map[chan Event]struct{})
+		}
 
-	// Only set the channel if there is not currently a matching one for this topic. This
-	// avoids registering two identical listeners for the same topic and causing pain in
-	// the unsubscribe functionality as well.
-	if _, exists := e.subscribers[topic][ch]; !exists {
-		e.subscribers[topic][ch] = struct{}{}
+		// Only set the channel if there is not currently a matching one for this topic. This
+		// avoids registering two identical listeners for the same topic and causing pain in
+		// the unsubscribe functionality as well.
+		if _, exists := e.subscribers[topic][ch]; !exists {
+			e.subscribers[topic][ch] = struct{}{}
+		}
 	}
 }
 
 // Unsubscribe a channel from a given topic.
-func (e *EventBus) Unsubscribe(topic string, ch chan Event) {
+func (e *EventBus) Unsubscribe(topics []string, ch chan Event) {
 	e.Lock()
 	defer e.Unlock()
 
-	if _, exists := e.subscribers[topic][ch]; exists {
-		delete(e.subscribers[topic], ch)
+	for _, topic := range topics {
+		if _, exists := e.subscribers[topic][ch]; exists {
+			delete(e.subscribers[topic], ch)
+		}
 	}
 }
 

router/websocket/listeners.go

@@ -50,24 +50,23 @@ var e = []string{
 // Listens for different events happening on a server and sends them along
 // to the connected websocket.
 func (h *Handler) ListenForServerEvents(ctx context.Context) {
-	eventChannel := make(chan events.Event)
-	for _, event := range e {
-		h.server.Events().Subscribe(event, eventChannel)
-	}
+	h.server.Log().Debug("listening for server events over websocket")
 
-	for d := range eventChannel {
+	eventChannel := make(chan events.Event)
+	h.server.Events().Subscribe(e, eventChannel)
+
+	go func(ctx context.Context) {
 		select {
 		case <-ctx.Done():
-			for _, event := range e {
-				h.server.Events().Unsubscribe(event, eventChannel)
-			}
+			h.server.Events().Unsubscribe(e, eventChannel)
 
 			close(eventChannel)
-		default:
-			_ = h.SendJson(&Message{
-				Event: d.Topic,
-				Args:  []string{d.Data},
-			})
+		}
+	}(ctx)
+
+	for d := range eventChannel {
+		if err := h.SendJson(&Message{Event: d.Topic, Args: []string{d.Data}}); err != nil {
+			h.server.Log().WithField("error", err).Warn("error while sending server data over websocket")
 		}
 	}
 }

router/websocket/websocket.go

@@ -95,6 +95,8 @@ func (h *Handler) SendJson(v *Message) error {
 	// Do not send JSON down the line if the JWT on the connection is not
 	// valid!
 	if err := h.TokenValid(); err != nil {
+		h.server.Log().WithField("error", err).Warn("invalid JWT detected for server websocket!")
+
 		return nil
 	}
 
@@ -157,9 +159,10 @@ func (h *Handler) TokenValid() error {
 // error message, otherwise we just send back a standard error message.
 func (h *Handler) SendErrorJson(msg Message, err error, shouldLog ...bool) error {
 	j := h.GetJwt()
+	expected := errors.Is(err, server.ErrSuspended) || errors.Is(err, server.ErrIsRunning)
 
 	message := "an unexpected error was encountered while handling this request"
-	if server.IsSuspendedError(err) || (j != nil && j.HasPermission(PermissionReceiveErrors)) {
+	if expected || (j != nil && j.HasPermission(PermissionReceiveErrors)) {
 		message = err.Error()
 	}
 
@@ -169,7 +172,7 @@ func (h *Handler) SendErrorJson(msg Message, err error, shouldLog ...bool) error
 	wsm.Args = []string{m}
 
 	if len(shouldLog) == 0 || (len(shouldLog) == 1 && shouldLog[0] == true) {
-		if !server.IsSuspendedError(err) {
+		if !expected {
 			h.server.Log().WithFields(log.Fields{"event": msg.Event, "error_identifier": u.String(), "error": err}).
 				Error("failed to handle websocket process; an error was encountered processing an event")
 		}
@@ -313,7 +316,7 @@ func (h *Handler) HandleInbound(m Message) error {
 				return nil
 			}
 
-			logs, err := h.server.Environment.Readlog(1024 * 16)
+			logs, err := h.server.Environment.Readlog(100)
 			if err != nil {
 				return err
 			}

server/errors.go

@@ -1,17 +1,9 @@
 package server
 
-type suspendedError struct {
-}
+import "github.com/pkg/errors"
 
-func (e *suspendedError) Error() string {
-	return "server is currently in a suspended state"
-}
-
-func IsSuspendedError(err error) bool {
-	_, ok := err.(*suspendedError)
-
-	return ok
-}
+var ErrIsRunning = errors.New("server is running")
+var ErrSuspended = errors.New("server is currently in a suspended state")
 
 type crashTooFrequent struct {
 }

server/filesystem.go

@@ -257,7 +257,7 @@ func (fs *Filesystem) HasSpaceAvailable(allowStaleValue bool) bool {
 func (fs *Filesystem) DiskUsage(allowStaleValue bool) (int64, error) {
 	// Check if cache is expired.
 	fs.lookupTimeMu.RLock()
-	isValidInCache := fs.lastLookupTime.After(time.Now().Add(time.Second * -10))
+	isValidInCache := fs.lastLookupTime.After(time.Now().Add(time.Second * time.Duration(-1*config.Get().System.DiskCheckInterval)))
 	fs.lookupTimeMu.RUnlock()
 
 	if !isValidInCache {

server/listeners.go

@@ -17,10 +17,6 @@ func (s *Server) StartEventListeners() {
 	state := make(chan events.Event)
 	stats := make(chan events.Event)
 
-	s.Environment.Events().Subscribe(environment.ConsoleOutputEvent, console)
-	s.Environment.Events().Subscribe(environment.StateChangeEvent, state)
-	s.Environment.Events().Subscribe(environment.ResourceEvent, stats)
-
 	go func(console chan events.Event) {
 		for data := range console {
 			// Immediately emit this event back over the server event stream since it is
@@ -31,12 +27,16 @@ func (s *Server) StartEventListeners() {
 			// Also pass the data along to the console output channel.
 			s.onConsoleOutput(data.Data)
 		}
+
+		s.Log().Fatal("unexpected end-of-range for server console channel")
 	}(console)
 
 	go func(state chan events.Event) {
 		for data := range state {
 			s.SetState(data.Data)
 		}
+
+		s.Log().Fatal("unexpected end-of-range for server state channel")
 	}(state)
 
 	go func(stats chan events.Event) {
@@ -56,7 +56,14 @@ func (s *Server) StartEventListeners() {
 
 			s.emitProcUsage()
 		}
+
+		s.Log().Fatal("unexpected end-of-range for server stats channel")
 	}(stats)
+
+	s.Log().Info("registering event listeners: console, state, resources...")
+	s.Environment.Events().Subscribe([]string{environment.ConsoleOutputEvent}, console)
+	s.Environment.Events().Subscribe([]string{environment.StateChangeEvent}, state)
+	s.Environment.Events().Subscribe([]string{environment.ResourceEvent}, stats)
 }
 
 var stripAnsiRegex = regexp.MustCompile("[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))")

server/loader.go

@@ -118,7 +118,7 @@ func FromConfiguration(data *api.ServerConfigurationResponse) (*Server, error) {
 		return nil, err
 	} else {
 		s.Environment = env
-		go s.StartEventListeners()
+		s.StartEventListeners()
 	}
 
 	// Forces the configuration to be synced with the panel.

server/power.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/config"
+	"github.com/pterodactyl/wings/environment"
 	"golang.org/x/sync/semaphore"
 	"os"
 	"time"
@@ -87,6 +88,10 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 
 	switch action {
 	case PowerActionStart:
+		if s.GetState() != environment.ProcessOfflineState {
+			return ErrIsRunning
+		}
+
 		// Run the pre-boot logic for the server before processing the environment start.
 		if err := s.onBeforeStart(); err != nil {
 			return err
@@ -134,7 +139,7 @@ func (s *Server) onBeforeStart() error {
 	// Disallow start & restart if the server is suspended. Do this check after performing a sync
 	// action with the Panel to ensure that we have the most up-to-date information for that server.
 	if s.IsSuspended() {
-		return new(suspendedError)
+		return ErrSuspended
 	}
 
 	// Ensure we sync the server information with the environment so that any new environment variables