Don't run pre-boot actions if the server is already running

router/websocket/websocket.go

@@ -159,9 +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()
 	}
 
@@ -171,7 +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")
 		}

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/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