Allow sending a termination signal even if another power action is being processed

server/power.go

@@ -53,6 +53,12 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 		s.powerLock = semaphore.NewWeighted(1)
 	}
 
+	// Only attempt to acquire a lock on the process if this is not a termination event. We want to
+	// just allow those events to pass right through for good reason. If a server is currently trying
+	// to process a power action but has gotten stuck you still should be able to pass through the
+	// terminate event. The good news here is that doing that oftentimes will get the stuck process to
+	// move again, and naturally continue through the process.
+	if action != PowerActionTerminate {
 		// Determines if we should wait for the lock or not. If a value greater than 0 is passed
 		// into this function we will wait that long for a lock to be acquired.
 		if len(waitSeconds) > 0 && waitSeconds[0] != 0 {
@@ -73,7 +79,18 @@ func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error
 
 		// Release the lock once the process being requested has finished executing.
 		defer s.powerLock.Release(1)
+	} else {
+		// Still try to acquire the lock if terminating and it is available, just so that other power
+		// actions are blocked until it has completed. However, if it is unavailable we won't stop
+		// the entire process.
+		if ok := s.powerLock.TryAcquire(1); ok {
+			// If we managed to acquire the lock be sure to released it once this process is completed.
+			defer s.powerLock.Release(1)
+		}
+	}
 
+	// Ensure the server data is properly synced before attempting to start the process, and that there
+	// is enough disk space available.
 	if action.IsStart() {
 		s.Log().Info("syncing server configuration with panel")
 		if err := s.Sync(); err != nil {