Add support for reinstalling a server

http.go

@@ -479,6 +479,20 @@ func (rt *Router) routeCreateServer(w http.ResponseWriter, r *http.Request, ps h
 	w.WriteHeader(http.StatusAccepted)
 }
 
+func (rt *Router) routeServerReinstall(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
+	s := rt.GetServer(ps.ByName("server"))
+	defer r.Body.Close()
+
+	zap.S().Infow("beginning reinstall process for server", zap.String("server", s.Uuid))
+	go func(server *server.Server) {
+		if err := server.Reinstall(); err != nil {
+			zap.S().Errorw("failed to complete server reinstall process", zap.String("server", server.Uuid), zap.Error(err))
+		}
+	}(s)
+
+	w.WriteHeader(http.StatusAccepted)
+}
+
 func (rt *Router) routeSystemInformation(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	defer r.Body.Close()
 
@@ -573,6 +587,7 @@ func (rt *Router) ConfigureRouter() *httprouter.Router {
 	router.POST("/api/servers/:server/files/delete", rt.AuthenticateRequest(rt.routeServerDeleteFile))
 	router.POST("/api/servers/:server/power", rt.AuthenticateRequest(rt.routeServerPower))
 	router.POST("/api/servers/:server/commands", rt.AuthenticateRequest(rt.routeServerSendCommand))
+	router.POST("/api/servers/:server/reinstall", rt.AuthenticateRequest(rt.routeServerReinstall))
 	router.PATCH("/api/servers/:server", rt.AuthenticateRequest(rt.routeServerUpdate))
 	router.DELETE("/api/servers/:server", rt.AuthenticateRequest(rt.routeServerDelete))
 

server/environment.go

@@ -31,6 +31,11 @@ type Environment interface {
 	// not be returned.
 	Stop() error
 
+	// Waits for a server instance to stop gracefully. If the server is still detected
+	// as running after seconds, an error will be returned, or the server will be terminated
+	// depending on the value of the second argument.
+	WaitForStop(seconds int, terminate bool) error
+
 	// Determines if the server instance exists. For example, in a docker environment
 	// this should confirm that the container is created and in a bootable state. In
 	// a basic CLI environment this can probably just return true right away.

server/environment_docker.go

@@ -267,6 +267,44 @@ func (d *DockerEnvironment) Stop() error {
 	return d.Client.ContainerStop(context.Background(), d.Server.Uuid, &t)
 }
 
+// Attempts to gracefully stop a server using the defined stop command. If the server
+// does not stop after seconds have passed, an error will be returned, or the instance
+// will be terminated forcefully depending on the value of the second argument.
+func (d *DockerEnvironment) WaitForStop(seconds int, terminate bool) error {
+	if d.Server.State == ProcessOfflineState {
+		return nil
+	}
+
+	if err := d.Stop(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(seconds)*time.Second)
+	defer cancel()
+
+	// Block the return of this function until the container as been marked as no
+	// longer running. If this wait does not end by the time seconds have passed,
+	// attempt to terminate the container, or return an error.
+	ok, errChan := d.Client.ContainerWait(ctx, d.Server.Uuid, container.WaitConditionNotRunning)
+	select {
+	case <-ctx.Done():
+		if ctxErr := ctx.Err(); ctxErr != nil {
+			if terminate {
+				return d.Terminate(os.Kill)
+			}
+
+			return errors.WithStack(ctxErr)
+		}
+	case err := <-errChan:
+		if err != nil {
+			return errors.WithStack(err)
+		}
+	case <-ok:
+	}
+
+	return nil
+}
+
 // Forcefully terminates the container using the signal passed through.
 func (d *DockerEnvironment) Terminate(signal os.Signal) error {
 	ctx := context.Background()

server/install.go

@@ -36,6 +36,19 @@ func (s *Server) Install() error {
 	return err
 }
 
+// Reinstalls a server's software by utilizing the install script for the server egg. This
+// does not touch any existing files for the server, other than what the script modifies.
+func (s *Server) Reinstall() error {
+	if s.State != ProcessOfflineState {
+		zap.S().Debugw("waiting for server instance to enter a stopped state", zap.String("server", s.Uuid))
+		if err := s.Environment.WaitForStop(10, true); err != nil {
+			return err
+		}
+	}
+
+	return s.Install()
+}
+
 // Internal installation function used to simplify reporting back to the Panel.
 func (s *Server) internalInstall() error {
 	script, rerr, err := api.NewRequester().GetInstallationScript(s.Uuid)