Enable plugin to work with latest versions of Mattermost

plugin.json

@@ -2,8 +2,8 @@
     "id": "jitsi",
     "name": "Jitsi",
     "description": "Jitsi audio and video conferencing plugin for Mattermost. Follow https://github.com/seansackowitz/mattermost-plugin-jitsi for notifications on updates.",
-    "version": "1.0.0",
-    "backend": {
+    "version": "1.1.0",
+    "server": {
         "executable": "server/plugin.exe"
     },
     "webapp": {

server/configuration.go

@@ -0,0 +1,97 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License for license information.
+
+package main
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/pkg/errors"
+)
+
+// configuration captures the plugin's external configuration as exposed in the Mattermost server
+// configuration, as well as values computed from the configuration. Any public fields will be
+// deserialized from the Mattermost server configuration in OnConfigurationChange.
+//
+// As plugins are inherently concurrent (hooks being called asynchronously), and the plugin
+// configuration can change at any time, access to the configuration must be synchronized. The
+// strategy used in this plugin is to guard a pointer to the configuration, and clone the entire
+// struct whenever it changes. You may replace this with whatever strategy you choose.
+//
+// If you add non-reference types to your configuration struct, be sure to rewrite Clone as a deep
+// copy appropriate for your types.
+type configuration struct {
+	JitsiURL string
+}
+
+// Clone shallow copies the configuration. Your implementation may require a deep copy if
+// your configuration has reference types.
+func (c *configuration) Clone() *configuration {
+	var clone = *c
+	return &clone
+}
+
+// IsValid checks if all needed fields are set.
+func (c *configuration) IsValid() error {
+	if len(c.JitsiURL) == 0 {
+		return fmt.Errorf("JitsiUrl is not configured.")
+	}
+
+	return nil
+}
+
+// getConfiguration retrieves the active configuration under lock, making it safe to use
+// concurrently. The active configuration may change underneath the client of this method, but
+// the struct returned by this API call is considered immutable.
+func (p *Plugin) getConfiguration() *configuration {
+	p.configurationLock.RLock()
+	defer p.configurationLock.RUnlock()
+
+	if p.configuration == nil {
+		return &configuration{}
+	}
+
+	return p.configuration
+}
+
+// setConfiguration replaces the active configuration under lock.
+//
+// Do not call setConfiguration while holding the configurationLock, as sync.Mutex is not
+// reentrant. In particular, avoid using the plugin API entirely, as this may in turn trigger a
+// hook back into the plugin. If that hook attempts to acquire this lock, a deadlock may occur.
+//
+// This method panics if setConfiguration is called with the existing configuration. This almost
+// certainly means that the configuration was modified without being cloned and may result in
+// an unsafe access.
+func (p *Plugin) setConfiguration(configuration *configuration) {
+	p.configurationLock.Lock()
+	defer p.configurationLock.Unlock()
+
+	if configuration != nil && p.configuration == configuration {
+		// Ignore assignment if the configuration struct is empty. Go will optimize the
+		// allocation for same to point at the same memory address, breaking the check
+		// above.
+		if reflect.ValueOf(*configuration).NumField() == 0 {
+			return
+		}
+
+		panic("setConfiguration called with the existing configuration")
+	}
+
+	p.configuration = configuration
+}
+
+// OnConfigurationChange is invoked when configuration changes may have been made.
+func (p *Plugin) OnConfigurationChange() error {
+	var configuration = new(configuration)
+
+	// Load the public configuration fields from the Mattermost server configuration.
+	if err := p.API.LoadPluginConfiguration(configuration); err != nil {
+		return errors.Wrap(err, "failed to load plugin configuration")
+	}
+
+	p.setConfiguration(configuration)
+
+	return nil
+}

server/plugin.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"regexp"
 	"strings"
+	"sync"
 
 	"github.com/mattermost/mattermost-server/model"
 	"github.com/mattermost/mattermost-server/plugin"
@@ -19,29 +20,20 @@ const (
 type Plugin struct {
 	plugin.MattermostPlugin
 
-	JitsiURL string
-}
-
-// func (p *Plugin) OnActivate() error {
-// 	if err := p.IsConfigurationValid(); err != nil {
-// 		return err
-// 	}
-
-// 	return nil
-// }
+	// configurationLock synchronizes access to the configuration.
+	configurationLock sync.RWMutex
 
-// func (p *Plugin) OnConfigurationChange() error {
-// 	if err := p.IsConfigurationValid(); err != nil {
-// 		return err
-// 	}
-
-// 	return nil
-// }
+	// configuration is the active plugin configuration. Consult getConfiguration and
+	// setConfiguration for usage.
+	configuration *configuration
+}
 
-func (p *Plugin) IsConfigurationValid() error {
-	if len(p.JitsiURL) == 0 {
-		return fmt.Errorf("Jitsi URL is not configured")
+func (p *Plugin) OnActivate() error {
+	config := p.getConfiguration()
+	if err := config.IsValid(); err != nil {
+		return err
 	}
+
 	return nil
 }
 
@@ -70,7 +62,7 @@ func encodeJitsiMeetingID(meeting string) string {
 }
 
 func (p *Plugin) handleStartMeeting(w http.ResponseWriter, r *http.Request) {
-	if err := p.IsConfigurationValid(); err != nil {
+	if err := p.getConfiguration().IsValid(); err != nil {
 		http.Error(w, err.Error(), http.StatusTeapot)
 		return
 	}
@@ -105,7 +97,7 @@ func (p *Plugin) handleStartMeeting(w http.ResponseWriter, r *http.Request) {
 	if len(req.Topic) < 1 {
 		meetingID = generateRoomWithoutSeparator()
 	}
-	jitsiURL := strings.TrimSpace(p.JitsiURL)
+	jitsiURL := strings.TrimSpace(p.getConfiguration().JitsiURL)
 	meetingURL := jitsiURL + "/" + meetingID
 
 	post := &model.Post{

webapp/package.json

@@ -1,6 +1,6 @@
 {
   "name": "jitsi",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "description": "Jitsi audio and video conferencing plugin for Mattermost",
   "dependencies": {
     "mattermost-redux": "1.0.1",