Improve server state logical handling; allow setting state directly on the environment

cmd/root.go

@@ -229,7 +229,7 @@ func rootCmdRun(*cobra.Command, []string) {
 				// is that it was running, but we see that the container process is not currently running.
 				s.Log().Info("detected server is running, re-attaching to process...")
 
-				s.SetState(environment.ProcessRunningState)
+				s.Environment.SetState(environment.ProcessRunningState)
 				if err := s.Environment.Attach(); err != nil {
 					s.Log().WithField("error", errors.WithStack(err)).Warn("failed to attach to running server environment")
 				}
@@ -239,7 +239,7 @@ func rootCmdRun(*cobra.Command, []string) {
 
 			// Addresses potentially invalid data in the stored file that can cause Wings to lose
 			// track of what the actual server state is.
-			_ = s.SetState(environment.ProcessOfflineState)
+			s.Environment.SetState(environment.ProcessOfflineState)
 		})
 	}
 
@@ -277,34 +277,20 @@ func rootCmdRun(*cobra.Command, []string) {
 		Handler: r,
 
 		TLSConfig: &tls.Config{
-			NextProtos: []string{
+			NextProtos: []string{"h2", "http/1.1"},
-				"h2", // enable HTTP/2
+			// @see https://blog.cloudflare.com/exposing-go-on-the-internet
-				"http/1.1",
-			},
-
-			// https://blog.cloudflare.com/exposing-go-on-the-internet
 			CipherSuites: []uint16{
 				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
 				tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
-
 				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 				tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
-
 				tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
-
 				tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
 			},
-
 			PreferServerCipherSuites: true,
-
 			MinVersion:               tls.VersionTLS12,
 			MaxVersion:               tls.VersionTLS13,
-
+			CurvePreferences:         []tls.CurveID{tls.X25519, tls.CurveP256},
-			CurvePreferences: []tls.CurveID{
-				tls.X25519,
-				tls.CurveP256,
-			},
-			// END https://blog.cloudflare.com/exposing-go-on-the-internet
 		},
 	}
 

environment/docker/container.go

@@ -60,7 +60,7 @@ func (e *Environment) Attach() error {
 		defer cancel()
 		defer e.stream.Close()
 		defer func() {
-			e.setState(environment.ProcessOfflineState)
+			e.SetState(environment.ProcessOfflineState)
 			e.SetStream(nil)
 		}()
 
@@ -245,7 +245,7 @@ func (e *Environment) convertMounts() []mount.Mount {
 // it will be forcibly stopped by Docker.
 func (e *Environment) Destroy() error {
 	// We set it to stopping than offline to prevent crash detection from being triggered.
-	e.setState(environment.ProcessStoppingState)
+	e.SetState(environment.ProcessStoppingState)
 
 	err := e.client.ContainerRemove(context.Background(), e.Id, types.ContainerRemoveOptions{
 		RemoveVolumes: true,
@@ -261,7 +261,7 @@ func (e *Environment) Destroy() error {
 		return nil
 	}
 
-	e.setState(environment.ProcessOfflineState)
+	e.SetState(environment.ProcessOfflineState)
 
 	return err
 }

environment/docker/environment.go

@@ -48,7 +48,7 @@ type Environment struct {
 	emitter *events.EventBus
 
 	// Tracks the environment state.
-	State system.AtomicString
+	st system.AtomicString
 }
 
 // Creates a new base Docker environment. The ID passed through will be the ID that is used to
@@ -67,7 +67,7 @@ func New(id string, m *Metadata, c *environment.Configuration) (*Environment, er
 		client:        cli,
 	}
 
-	e.State.Store(environment.ProcessOfflineState)
+	e.st.Store(environment.ProcessOfflineState)
 
 	return e, nil
 }

environment/docker/power.go

@@ -57,8 +57,8 @@ func (e *Environment) Start() error {
 			// If we don't set it to stopping first, you'll trigger crash detection which
 			// we don't want to do at this point since it'll just immediately try to do the
 			// exact same action that lead to it crashing in the first place...
-			e.setState(environment.ProcessStoppingState)
+			e.SetState(environment.ProcessStoppingState)
-			e.setState(environment.ProcessOfflineState)
+			e.SetState(environment.ProcessOfflineState)
 		}
 	}()
 
@@ -74,7 +74,7 @@ func (e *Environment) Start() error {
 	} else {
 		// If the server is running update our internal state and continue on with the attach.
 		if c.State.Running {
-			e.setState(environment.ProcessRunningState)
+			e.SetState(environment.ProcessRunningState)
 
 			return e.Attach()
 		}
@@ -89,7 +89,7 @@ func (e *Environment) Start() error {
 		}
 	}
 
-	e.setState(environment.ProcessStartingState)
+	e.SetState(environment.ProcessStartingState)
 
 	// Set this to true for now, we will set it to false once we reach the
 	// end of this chain.
@@ -136,8 +136,8 @@ func (e *Environment) Stop() error {
 
 	// If the process is already offline don't switch it back to stopping. Just leave it how
 	// it is and continue through to the stop handling for the process.
-	if e.State.Load() != environment.ProcessOfflineState {
+	if e.st.Load() != environment.ProcessOfflineState {
-		e.setState(environment.ProcessStoppingState)
+		e.SetState(environment.ProcessStoppingState)
 	}
 
 	// Only attempt to send the stop command to the instance if we are actually attached to
@@ -153,7 +153,7 @@ func (e *Environment) Stop() error {
 		// an error.
 		if client.IsErrNotFound(err) {
 			e.SetStream(nil)
-			e.setState(environment.ProcessOfflineState)
+			e.SetState(environment.ProcessOfflineState)
 
 			return nil
 		}
@@ -217,16 +217,16 @@ func (e *Environment) Terminate(signal os.Signal) error {
 		// If the container is not running but we're not already in a stopped state go ahead
 		// and update things to indicate we should be completely stopped now. Set to stopping
 		// first so crash detection is not triggered.
-		if e.State.Load() != environment.ProcessOfflineState {
+		if e.st.Load() != environment.ProcessOfflineState {
-			e.setState(environment.ProcessStoppingState)
+			e.SetState(environment.ProcessStoppingState)
-			e.setState(environment.ProcessOfflineState)
+			e.SetState(environment.ProcessOfflineState)
 		}
 
 		return nil
 	}
 
 	// We set it to stopping than offline to prevent crash detection from being triggered.
-	e.setState(environment.ProcessStoppingState)
+	e.SetState(environment.ProcessStoppingState)
 
 	sig := strings.TrimSuffix(strings.TrimPrefix(signal.String(), "signal "), "ed")
 
@@ -234,7 +234,7 @@ func (e *Environment) Terminate(signal os.Signal) error {
 		return err
 	}
 
-	e.setState(environment.ProcessOfflineState)
+	e.SetState(environment.ProcessOfflineState)
 
 	return nil
 }

environment/docker/state.go

@@ -6,25 +6,24 @@ import (
 	"github.com/pterodactyl/wings/environment"
 )
 
+func (e *Environment) State() string {
+	return e.st.Load()
+}
+
 // Sets the state of the environment. This emits an event that server's can hook into to
 // take their own actions and track their own state based on the environment.
-func (e *Environment) setState(state string) error {
+func (e *Environment) SetState(state string) {
 	if state != environment.ProcessOfflineState &&
 		state != environment.ProcessStartingState &&
 		state != environment.ProcessRunningState &&
 		state != environment.ProcessStoppingState {
-		return errors.New(fmt.Sprintf("invalid server state received: %s", state))
+		panic(errors.New(fmt.Sprintf("invalid server state received: %s", state)))
 	}
 
-	// Get the current state of the environment before changing it.
-	prevState := e.State.Load()
-
 	// Emit the event to any listeners that are currently registered.
-	if prevState != state {
+	if e.State() != state {
 		// If the state changed make sure we update the internal tracking to note that.
-		e.State.Store(state)
+		e.st.Store(state)
 		e.Events().Publish(environment.StateChangeEvent, state)
 	}
-
-	return nil
 }

environment/docker/stats.go

@@ -20,7 +20,7 @@ func (e *Environment) pollResources(ctx context.Context) error {
 	l.Debug("starting resource polling for container")
 	defer l.Debug("stopped resource polling for container")
 
-	if e.State.Load() == environment.ProcessOfflineState {
+	if e.st.Load() == environment.ProcessOfflineState {
 		return errors.New("cannot enable resource polling on a stopped server")
 	}
 
@@ -50,7 +50,7 @@ func (e *Environment) pollResources(ctx context.Context) error {
 			}
 
 			// Disable collection if the server is in an offline state and this process is still running.
-			if e.State.Load() == environment.ProcessOfflineState {
+			if e.st.Load() == environment.ProcessOfflineState {
 				l.Debug("process in offline state while resource polling is still active; stopping poll")
 				return nil
 			}

environment/docker/stream.go

@@ -37,7 +37,7 @@ func (e *Environment) SendCommand(c string) error {
 	// the server as entering the stopping state otherwise the process will stop and Wings will think
 	// it has crashed and attempt to restart it.
 	if e.meta.Stop.Type == "command" && c == e.meta.Stop.Value {
-		e.Events().Publish(environment.StateChangeEvent, environment.ProcessStoppingState)
+		e.SetState(environment.ProcessStoppingState)
 	}
 
 	_, err := e.stream.Conn.Write([]byte(c + "\n"))

environment/environment.go

@@ -94,4 +94,12 @@ type ProcessEnvironment interface {
 	// Reads the log file for the process from the end backwards until the provided
 	// number of lines is met.
 	Readlog(int) ([]string, error)
+
+	// Returns the current state of the environment.
+	State() string
+
+	// Sets the current state of the environment. In general you should let the environment
+	// handle this itself, but there are some scenarios where it is helpful for the server
+	// to update the state externally (e.g. starting -> started).
+	SetState(string)
 }

server/install.go

@@ -63,7 +63,7 @@ func (s *Server) Install(sync bool) error {
 
 	// Ensure that the server is marked as offline at this point, otherwise you end up
 	// with a blank value which is a bit confusing.
-	s.SetState(environment.ProcessOfflineState)
+	s.Environment.SetState(environment.ProcessOfflineState)
 
 	// Push an event to the websocket so we can auto-refresh the information in the panel once
 	// the install is completed.

server/listeners.go

@@ -63,8 +63,8 @@ func (s *Server) StartEventListeners() {
 		if err != nil {
 			// If the process is already stopping, just let it continue with that action rather than attempting
 			// to terminate again.
-			if s.GetState() != environment.ProcessStoppingState {
+			if s.Environment.State() != environment.ProcessStoppingState {
-				s.SetState(environment.ProcessStoppingState)
+				s.Environment.SetState(environment.ProcessStoppingState)
 				go func() {
 					s.Log().Warn("stopping server instance, violating throttle limits")
 					s.PublishConsoleOutputFromDaemon("Your server is being stopped for outputting too much data in a short period of time.")
@@ -73,8 +73,8 @@ func (s *Server) StartEventListeners() {
 					if err := s.Environment.WaitForStop(config.Get().Throttles.StopGracePeriod, true); err != nil {
 						// If there is an error set the process back to running so that this throttler is called
 						// again and hopefully kills the server.
-						if s.GetState() != environment.ProcessOfflineState {
+						if s.Environment.State() != environment.ProcessOfflineState {
-							s.SetState(environment.ProcessRunningState)
+							s.Environment.SetState(environment.ProcessRunningState)
 						}
 
 						s.Log().WithField("error", errors.WithStack(err)).Error("failed to terminate environment after triggering throttle")
@@ -100,7 +100,7 @@ func (s *Server) StartEventListeners() {
 			s.Throttler().Reset()
 		}
 
-		s.SetState(e.Data)
+		s.OnStateChange()
 	}
 
 	stats := func(e events.Event) {
@@ -173,7 +173,7 @@ 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.
-			_ = s.SetState(environment.ProcessRunningState)
+			s.Environment.SetState(environment.ProcessRunningState)
 			break
 		}
 	}
@@ -185,7 +185,7 @@ func (s *Server) onConsoleOutput(data string) {
 		stop := processConfiguration.Stop
 
 		if stop.Type == api.ProcessStopCommand && data == stop.Value {
-			_ = s.SetState(environment.ProcessOfflineState)
+			s.Environment.SetState(environment.ProcessOfflineState)
 		}
 	}
 }

server/loader.go

@@ -104,6 +104,7 @@ func FromConfiguration(data api.ServerConfigurationResponse) (*Server, error) {
 
 	s.resources = ResourceUsage{}
 	defaults.Set(&s.resources)
+	s.resources.State.Store(environment.ProcessOfflineState)
 
 	s.Archiver = Archiver{Server: s}
 	s.fs = filesystem.New(filepath.Join(config.Get().System.Data, s.Id()), s.DiskSpace())

server/resources.go

@@ -3,7 +3,9 @@ package server
 import (
 	"encoding/json"
 	"github.com/pterodactyl/wings/environment"
+	"github.com/pterodactyl/wings/system"
 	"sync"
+	"sync/atomic"
 )
 
 // Defines the current resource usage for a given server instance. If a server is offline you
@@ -16,7 +18,7 @@ type ResourceUsage struct {
 	environment.Stats
 
 	// The current server status.
-	State string `json:"state" default:"offline"`
+	State system.AtomicString `json:"state"`
 
 	// The current disk space being used by the server. This value is not guaranteed to be accurate
 	// at all times. It is "manually" set whenever server.Proc() is called. This is kind of just a
@@ -24,16 +26,16 @@ type ResourceUsage struct {
 	Disk int64 `json:"disk_bytes"`
 }
 
-// Alias the resource usage so that we don't infinitely recurse when marshaling the struct.
-type IResourceUsage ResourceUsage
-
 // Custom marshaler to ensure that the object is locked when we're converting it to JSON in
 // order to avoid race conditions.
 func (ru *ResourceUsage) MarshalJSON() ([]byte, error) {
 	ru.mu.Lock()
 	defer ru.mu.Unlock()
 
-	return json.Marshal(IResourceUsage(*ru))
+	// Alias the resource usage so that we don't infinitely recurse when marshaling the struct.
+	type alias ResourceUsage
+
+	return json.Marshal(alias(*ru))
 }
 
 // Returns the resource usage stats for the server instance. If the server is not running, only the
@@ -42,10 +44,10 @@ func (ru *ResourceUsage) MarshalJSON() ([]byte, error) {
 //
 // When a process is stopped all of the stats are zeroed out except for the disk.
 func (s *Server) Proc() *ResourceUsage {
-	s.resources.SetDisk(s.Filesystem().CachedUsage())
+	// Store the updated disk usage when requesting process usage.
+	atomic.StoreInt64(&s.resources.Disk, s.Filesystem().CachedUsage())
 
-	// Get a read lock on the resources at this point. Don't do this before setting
+	// Acquire a lock before attempting to return the value of resources.
-	// the disk, otherwise you'll cause a deadlock.
 	s.resources.mu.RLock()
 	defer s.resources.mu.RUnlock()
 
@@ -57,24 +59,3 @@ func (s *Server) emitProcUsage() {
 		s.Log().WithField("error", err).Warn("error while emitting server resource usage to listeners")
 	}
 }
-
-// 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()
-}
-
-func (ru *ResourceUsage) SetDisk(i int64) {
-	ru.mu.Lock()
-	ru.Disk = i
-	ru.mu.Unlock()
-}

server/state.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"encoding/json"
-	"fmt"
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
@@ -63,23 +62,17 @@ func saveServerStates() error {
 
 // 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 {
+func (s *Server) OnStateChange() {
-	if state != environment.ProcessOfflineState &&
+	prevState := s.Proc().State.Load()
-		state != environment.ProcessStartingState &&
-		state != environment.ProcessRunningState &&
-		state != environment.ProcessStoppingState {
-		return errors.New(fmt.Sprintf("invalid server state received: %s", state))
-	}
-
-	prevState := s.GetState()
 
+	st := s.Environment.State()
 	// Update the currently tracked state for the server.
-	s.Proc().setInternalState(state)
+	s.Proc().State.Store(st)
 
 	// Emit the event to any listeners that are currently registered.
-	if prevState != state {
+	if prevState != s.Environment.State() {
-		s.Log().WithField("status", s.Proc().getInternalState()).Debug("saw server status change event")
+		s.Log().WithField("status", st).Debug("saw server status change event")
-		s.Events().Publish(StatusEvent, s.Proc().getInternalState())
+		s.Events().Publish(StatusEvent, st)
 	}
 
 	// Persist this change to the disk immediately so that should the Daemon be stopped or
@@ -98,7 +91,7 @@ func (s *Server) SetState(state string) error {
 
 	// Reset the resource usage to 0 when the process fully stops so that all of the UI
 	// views in the Panel correctly display 0.
-	if state == environment.ProcessOfflineState {
+	if st == environment.ProcessOfflineState {
 		s.resources.mu.Lock()
 		s.resources.Empty()
 		s.resources.mu.Unlock()
@@ -127,13 +120,13 @@ func (s *Server) SetState(state string) error {
 			}
 		}(s)
 	}
-
-	return nil
 }
 
 // Returns the current state of the server in a race-safe manner.
+// Deprecated
+// use Environment.State()
 func (s *Server) GetState() string {
-	return s.Proc().getInternalState()
+	return s.Environment.State()
 }
 
 // Determines if the server state is running or not. This is different than the