Refactor environment handling logic to separate a server from the environment handler itself

This change makes the environment handling logic execute independent of the server itself and should make it much easier for people to contribute changes and additional environment handlers down the road without polluting the server object even more.

There is still a lot of work to do on this front to make things easier to work with, and there are some questionable design decisions at play I'm sure.

Welcome to additional modifications and cleanup to make this code easier to reason about and work with.

server/power.go

@@ -32,6 +32,10 @@ func (pa PowerAction) IsValid() bool {
 		pa == PowerActionRestart
 }
 
+func (pa PowerAction) IsStart() bool {
+	return pa == PowerActionStart || pa == PowerActionRestart
+}
+
 // Helper function that can receive a power action and then process the actions that need
 // to occur for it. This guards against someone calling Start() twice at the same time, or
 // trying to restart while another restart process is currently running.
@@ -40,6 +44,11 @@ func (pa PowerAction) IsValid() bool {
 // function rather than making direct calls to the start/stop/restart functions on the
 // environment struct.
 func (s *Server) HandlePowerAction(action PowerAction, waitSeconds ...int) error {
+	// Disallow start & restart if the server is suspended.
+	if action.IsStart() && s.IsSuspended() {
+		return new(suspendedError)
+	}
+
 	if s.powerLock == nil {
 		s.powerLock = semaphore.NewWeighted(1)
 	}
@@ -65,6 +74,17 @@ 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)
 
+	if action.IsStart() {
+		s.Log().Info("syncing server configuration with panel")
+		if err := s.Sync(); err != nil {
+			return errors.WithStack(err)
+		}
+
+		if !s.Filesystem.HasSpaceAvailable() {
+			return errors.New("cannot start server, not enough disk space available")
+		}
+	}
+
 	switch action {
 	case PowerActionStart:
 		return s.Environment.Start()