PLT-7622 Improvements to server handling of webapp plugins (#7445)

* Improvements to server handling of webapp plugins

* Fix newline

* Update manifest function names

12 files changed, 183 insertions, 62 deletions

diff --git a/api4/plugin.go b/api4/plugin.go
index 5b030e71d..ac1620335 100644
--- a/api4/plugin.go
+++ b/api4/plugin.go
@@ -25,6 +25,8 @@ func InitPlugin() {
 	BaseRoutes.Plugins.Handle("", ApiSessionRequired(getPlugins)).Methods("GET")
 	BaseRoutes.Plugin.Handle("", ApiSessionRequired(removePlugin)).Methods("DELETE")
 
+	BaseRoutes.Plugins.Handle("/webapp", ApiHandler(getWebappPlugins)).Methods("GET")
+
 }
 
 func uploadPlugin(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -118,3 +120,25 @@ func removePlugin(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	ReturnStatusOK(w)
 }
+
+func getWebappPlugins(c *Context, w http.ResponseWriter, r *http.Request) {
+	if !*utils.Cfg.PluginSettings.Enable {
+		c.Err = model.NewAppError("getWebappPlugins", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	manifests, err := c.App.GetActivePluginManifests()
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	clientManifests := []*model.Manifest{}
+	for _, m := range manifests {
+		if m.HasClient() {
+			clientManifests = append(clientManifests, m.ClientManifest())
+		}
+	}
+
+	w.Write([]byte(model.ManifestListToJson(clientManifests)))
+}
diff --git a/api4/plugin_test.go b/api4/plugin_test.go
index f92e58ea0..9cedccfe7 100644
--- a/api4/plugin_test.go
+++ b/api4/plugin_test.go
@@ -17,14 +17,11 @@ import (
 func TestPlugin(t *testing.T) {
 	pluginDir, err := ioutil.TempDir("", "mm-plugin-test")
 	require.NoError(t, err)
-	defer func() {
-		os.RemoveAll(pluginDir)
-	}()
+	defer os.RemoveAll(pluginDir)
+
 	webappDir, err := ioutil.TempDir("", "mm-webapp-test")
 	require.NoError(t, err)
-	defer func() {
-		os.RemoveAll(webappDir)
-	}()
+	defer os.RemoveAll(webappDir)
 
 	th := SetupEnterprise().InitBasic().InitSystemAdmin()
 	defer TearDown()
@@ -50,9 +47,7 @@ func TestPlugin(t *testing.T) {
 
 	// Successful upload
 	manifest, resp := th.SystemAdminClient.UploadPlugin(file)
-	defer func() {
-		os.RemoveAll("plugins/testplugin")
-	}()
+	defer os.RemoveAll("plugins/testplugin")
 	CheckNoError(t, resp)
 
 	assert.Equal(t, "testplugin", manifest.Id)
@@ -91,6 +86,19 @@ func TestPlugin(t *testing.T) {
 	_, resp = th.Client.GetPlugins()
 	CheckForbiddenStatus(t, resp)
 
+	// Successful webapp get
+	manifests, resp = th.Client.GetWebappPlugins()
+	CheckNoError(t, resp)
+
+	found = false
+	for _, m := range manifests {
+		if m.Id == manifest.Id {
+			found = true
+		}
+	}
+
+	assert.True(t, found)
+
 	// Successful remove
 	ok, resp := th.SystemAdminClient.RemovePlugin(manifest.Id)
 	CheckNoError(t, resp)
diff --git a/api4/system.go b/api4/system.go
index fbfbd0ef2..b50dc97a5 100644
--- a/api4/system.go
+++ b/api4/system.go
@@ -244,7 +244,6 @@ func getClientConfig(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	respCfg["NoAccounts"] = strconv.FormatBool(c.App.IsFirstUserAccount())
-	respCfg["Plugins"] = c.App.GetPluginsForClientConfig()
 
 	w.Write([]byte(model.MapToJson(respCfg)))
 }
diff --git a/app/plugins.go b/app/plugins.go
index f00308a86..fb8182823 100644
--- a/app/plugins.go
+++ b/app/plugins.go
@@ -252,6 +252,12 @@ func (a *App) UnpackAndActivatePlugin(pluginFile io.Reader) (*model.Manifest, *m
 		return nil, model.NewAppError("UnpackAndActivatePlugin", "app.plugin.activate.app_error", nil, err.Error(), http.StatusBadRequest)
 	}
 
+	if manifest.HasClient() {
+		message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_PLUGIN_ACTIVATED, "", "", "", nil)
+		message.Add("manifest", manifest.ClientManifest())
+		Publish(message)
+	}
+
 	return manifest, nil
 }
 
@@ -260,10 +266,7 @@ func (a *App) GetActivePluginManifests() ([]*model.Manifest, *model.AppError) {
 		return nil, model.NewAppError("GetActivePluginManifests", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)
 	}
 
-	plugins, err := a.PluginEnv.ActivePlugins()
-	if err != nil {
-		return nil, model.NewAppError("GetActivePluginManifests", "app.plugin.get_plugins.app_error", nil, err.Error(), http.StatusInternalServerError)
-	}
+	plugins := a.PluginEnv.ActivePlugins()
 
 	manifests := make([]*model.Manifest, len(plugins))
 	for i, plugin := range plugins {
@@ -278,6 +281,15 @@ func (a *App) RemovePlugin(id string) *model.AppError {
 		return model.NewAppError("RemovePlugin", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)
 	}
 
+	plugins := a.PluginEnv.ActivePlugins()
+	manifest := &model.Manifest{}
+	for _, p := range plugins {
+		if p.Manifest.Id == id {
+			manifest = p.Manifest
+			break
+		}
+	}
+
 	err := a.PluginEnv.DeactivatePlugin(id)
 	if err != nil {
 		return model.NewAppError("RemovePlugin", "app.plugin.deactivate.app_error", nil, err.Error(), http.StatusBadRequest)
@@ -288,39 +300,13 @@ func (a *App) RemovePlugin(id string) *model.AppError {
 		return model.NewAppError("RemovePlugin", "app.plugin.remove.app_error", nil, err.Error(), http.StatusInternalServerError)
 	}
 
-	return nil
-}
-
-// Temporary WIP function/type for experimental webapp plugins
-type ClientConfigPlugin struct {
-	Id         string `json:"id"`
-	BundlePath string `json:"bundle_path"`
-}
-
-func (a *App) GetPluginsForClientConfig() string {
-	if a.PluginEnv == nil || !*utils.Cfg.PluginSettings.Enable {
-		return ""
-	}
-
-	plugins, err := a.PluginEnv.ActivePlugins()
-	if err != nil {
-		return ""
-	}
-
-	pluginsConfig := []ClientConfigPlugin{}
-	for _, plugin := range plugins {
-		if plugin.Manifest.Webapp == nil {
-			continue
-		}
-		pluginsConfig = append(pluginsConfig, ClientConfigPlugin{Id: plugin.Manifest.Id, BundlePath: plugin.Manifest.Webapp.BundlePath})
+	if manifest.HasClient() {
+		message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_PLUGIN_DEACTIVATED, "", "", "", nil)
+		message.Add("manifest", manifest.ClientManifest())
+		Publish(message)
 	}
 
-	b, err := json.Marshal(pluginsConfig)
-	if err != nil {
-		return ""
-	}
-
-	return string(b)
+	return nil
 }
 
 func (a *App) InitPlugins(pluginPath, webappPath string) {
@@ -338,6 +324,12 @@ func (a *App) InitPlugins(pluginPath, webappPath string) {
 		return
 	}
 
+	err = os.Mkdir(webappPath, 0744)
+	if err != nil && !os.IsExist(err) {
+		l4g.Error("failed to start up plugins: " + err.Error())
+		return
+	}
+
 	a.PluginEnv, err = pluginenv.New(
 		pluginenv.SearchPath(pluginPath),
 		pluginenv.WebappPath(webappPath),
diff --git a/cmd/platform/server.go b/cmd/platform/server.go
index 15c80134c..a8e724f58 100644
--- a/cmd/platform/server.go
+++ b/cmd/platform/server.go
@@ -62,11 +62,6 @@ func runServer(configFileLocation string) {
 	l4g.Info(utils.T("mattermost.working_dir"), pwd)
 	l4g.Info(utils.T("mattermost.config_file"), utils.FindConfigFile(configFileLocation))
 
-	// Enable developer settings if this is a "dev" build
-	if model.BuildNumber == "dev" {
-		*utils.Cfg.ServiceSettings.EnableDeveloper = true
-	}
-
 	if err := utils.TestFileConnection(); err != nil {
 		l4g.Error("Problem with file storage settings: " + err.Error())
 	}
@@ -79,7 +74,12 @@ func runServer(configFileLocation string) {
 	if model.BuildEnterpriseReady == "true" {
 		a.LoadLicense()
 	}
-	a.InitPlugins("plugins", "webapp/dist")
+
+	if webappDir, ok := utils.FindDir(model.CLIENT_DIR); ok {
+		a.InitPlugins("plugins", webappDir+"/plugins")
+	} else {
+		l4g.Error("Unable to find webapp directory, could not initialize plugins")
+	}
 
 	wsapi.InitRouter()
 	api4.InitApi(a.Srv.Router, false)
@@ -98,6 +98,11 @@ func runServer(configFileLocation string) {
 
 	app.ReloadConfig()
 
+	// Enable developer settings if this is a "dev" build
+	if model.BuildNumber == "dev" {
+		*utils.Cfg.ServiceSettings.EnableDeveloper = true
+	}
+
 	resetStatuses(a)
 
 	a.StartServer()
diff --git a/model/client4.go b/model/client4.go
index c06975697..44c4cf6c9 100644
--- a/model/client4.go
+++ b/model/client4.go
@@ -3088,3 +3088,14 @@ func (c *Client4) RemovePlugin(id string) (bool, *Response) {
 		return CheckStatusOK(r), BuildResponse(r)
 	}
 }
+
+// GetWebappPlugins will return a list of plugins that the webapp should download.
+// WARNING: PLUGINS ARE STILL EXPERIMENTAL. THIS FUNCTION IS SUBJECT TO CHANGE.
+func (c *Client4) GetWebappPlugins() ([]*Manifest, *Response) {
+	if r, err := c.DoApiGet(c.GetPluginsRoute()+"/webapp", ""); err != nil {
+		return nil, BuildErrorResponse(r, err)
+	} else {
+		defer closeBody(r)
+		return ManifestListFromJson(r.Body), BuildResponse(r)
+	}
+}
diff --git a/model/manifest.go b/model/manifest.go
index e61ccc8ad..b466660af 100644
--- a/model/manifest.go
+++ b/model/manifest.go
@@ -12,8 +12,9 @@ import (
 
 type Manifest struct {
 	Id          string           `json:"id" yaml:"id"`
-	Name        string           `json:"name" yaml:"name"`
-	Description string           `json:"description" yaml:"description"`
+	Name        string           `json:"name,omitempty" yaml:"name,omitempty"`
+	Description string           `json:"description,omitempty" yaml:"description,omitempty"`
+	Version     string           `json:"version" yaml:"version"`
 	Backend     *ManifestBackend `json:"backend,omitempty" yaml:"backend,omitempty"`
 	Webapp      *ManifestWebapp  `json:"webapp,omitempty" yaml:"webapp,omitempty"`
 }
@@ -66,6 +67,19 @@ func ManifestListFromJson(data io.Reader) []*Manifest {
 	}
 }
 
+func (m *Manifest) HasClient() bool {
+	return m.Webapp != nil
+}
+
+func (m *Manifest) ClientManifest() *Manifest {
+	cm := new(Manifest)
+	*cm = *m
+	cm.Name = ""
+	cm.Description = ""
+	cm.Backend = nil
+	return cm
+}
+
 // FindManifest will find and parse the manifest in a given directory.
 //
 // In all cases other than a does-not-exist error, path is set to the path of the manifest file that was
diff --git a/model/manifest_test.go b/model/manifest_test.go
index 46975cf47..1ec43a217 100644
--- a/model/manifest_test.go
+++ b/model/manifest_test.go
@@ -129,3 +129,51 @@ func TestManifestJson(t *testing.T) {
 	assert.Equal(t, newManifestList, manifestList)
 	assert.Equal(t, ManifestListToJson(newManifestList), json)
 }
+
+func TestManifestHasClient(t *testing.T) {
+	manifest := &Manifest{
+		Id: "theid",
+		Backend: &ManifestBackend{
+			Executable: "theexecutable",
+		},
+		Webapp: &ManifestWebapp{
+			BundlePath: "thebundlepath",
+		},
+	}
+
+	assert.True(t, manifest.HasClient())
+
+	manifest.Webapp = nil
+	assert.False(t, manifest.HasClient())
+}
+
+func TestManifestClientManifest(t *testing.T) {
+	manifest := &Manifest{
+		Id:          "theid",
+		Name:        "thename",
+		Description: "thedescription",
+		Version:     "0.0.1",
+		Backend: &ManifestBackend{
+			Executable: "theexecutable",
+		},
+		Webapp: &ManifestWebapp{
+			BundlePath: "thebundlepath",
+		},
+	}
+
+	sanitized := manifest.ClientManifest()
+
+	assert.NotEmpty(t, sanitized.Id)
+	assert.NotEmpty(t, sanitized.Version)
+	assert.NotEmpty(t, sanitized.Webapp)
+	assert.Empty(t, sanitized.Name)
+	assert.Empty(t, sanitized.Description)
+	assert.Empty(t, sanitized.Backend)
+
+	assert.NotEmpty(t, manifest.Id)
+	assert.NotEmpty(t, manifest.Version)
+	assert.NotEmpty(t, manifest.Webapp)
+	assert.NotEmpty(t, manifest.Name)
+	assert.NotEmpty(t, manifest.Description)
+	assert.NotEmpty(t, manifest.Backend)
+}
diff --git a/model/websocket_message.go b/model/websocket_message.go
index 6b8c03427..6c55da6f0 100644
--- a/model/websocket_message.go
+++ b/model/websocket_message.go
@@ -39,6 +39,8 @@ const (
 	WEBSOCKET_EVENT_RESPONSE            = "response"
 	WEBSOCKET_EVENT_EMOJI_ADDED         = "emoji_added"
 	WEBSOCKET_EVENT_CHANNEL_VIEWED      = "channel_viewed"
+	WEBSOCKET_EVENT_PLUGIN_ACTIVATED    = "plugin_activated"   // EXPERIMENTAL - SUBJECT TO CHANGE
+	WEBSOCKET_EVENT_PLUGIN_DEACTIVATED  = "plugin_deactivated" // EXPERIMENTAL - SUBJECT TO CHANGE
 )
 
 type WebSocketMessage interface {
diff --git a/plugin/pluginenv/environment.go b/plugin/pluginenv/environment.go
index e4a7f1b3b..805b33e66 100644
--- a/plugin/pluginenv/environment.go
+++ b/plugin/pluginenv/environment.go
@@ -66,7 +66,7 @@ func (env *Environment) Plugins() ([]*model.BundleInfo, error) {
 }
 
 // Returns a list of all currently active plugins within the environment.
-func (env *Environment) ActivePlugins() ([]*model.BundleInfo, error) {
+func (env *Environment) ActivePlugins() []*model.BundleInfo {
 	env.mutex.RLock()
 	defer env.mutex.RUnlock()
 
@@ -75,7 +75,7 @@ func (env *Environment) ActivePlugins() ([]*model.BundleInfo, error) {
 		activePlugins = append(activePlugins, p.BundleInfo)
 	}
 
-	return activePlugins, nil
+	return activePlugins
 }
 
 // Returns the ids of the currently active plugins.
diff --git a/plugin/pluginenv/environment_test.go b/plugin/pluginenv/environment_test.go
index f24ef8d3d..c11644b35 100644
--- a/plugin/pluginenv/environment_test.go
+++ b/plugin/pluginenv/environment_test.go
@@ -127,8 +127,7 @@ func TestEnvironment(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Len(t, plugins, 3)
 
-	activePlugins, err := env.ActivePlugins()
-	assert.NoError(t, err)
+	activePlugins := env.ActivePlugins()
 	assert.Len(t, activePlugins, 0)
 
 	assert.Error(t, env.ActivatePlugin("x"))
@@ -150,8 +149,7 @@ func TestEnvironment(t *testing.T) {
 
 	assert.NoError(t, env.ActivatePlugin("foo"))
 	assert.Equal(t, env.ActivePluginIds(), []string{"foo"})
-	activePlugins, err = env.ActivePlugins()
-	assert.NoError(t, err)
+	activePlugins = env.ActivePlugins()
 	assert.Len(t, activePlugins, 1)
 	assert.Error(t, env.ActivatePlugin("foo"))
 
diff --git a/web/web.go b/web/web.go
index c883c750d..f74c73cde 100644
--- a/web/web.go
+++ b/web/web.go
@@ -26,12 +26,17 @@ func InitWeb() {
 	if *utils.Cfg.ServiceSettings.WebserverMode != "disabled" {
 		staticDir, _ := utils.FindDir(model.CLIENT_DIR)
 		l4g.Debug("Using client directory at %v", staticDir)
+
+		staticHandler := staticHandler(http.StripPrefix("/static/", http.FileServer(http.Dir(staticDir))))
+		pluginHandler := pluginHandler(http.StripPrefix("/static/plugins/", http.FileServer(http.Dir(staticDir+"plugins/"))))
+
 		if *utils.Cfg.ServiceSettings.WebserverMode == "gzip" {
-			mainrouter.PathPrefix("/static/").Handler(gziphandler.GzipHandler(staticHandler(http.StripPrefix("/static/", http.FileServer(http.Dir(staticDir))))))
-		} else {
-			mainrouter.PathPrefix("/static/").Handler(staticHandler(http.StripPrefix("/static/", http.FileServer(http.Dir(staticDir)))))
+			staticHandler = gziphandler.GzipHandler(staticHandler)
+			pluginHandler = gziphandler.GzipHandler(pluginHandler)
 		}
 
+		mainrouter.PathPrefix("/static/plugins/").Handler(pluginHandler)
+		mainrouter.PathPrefix("/static/").Handler(staticHandler)
 		mainrouter.Handle("/{anything:.*}", api.AppHandlerIndependent(root)).Methods("GET")
 	}
 }
@@ -47,6 +52,21 @@ func staticHandler(handler http.Handler) http.Handler {
 	})
 }
 
+func pluginHandler(handler http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if *utils.Cfg.ServiceSettings.EnableDeveloper {
+			w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+		} else {
+			w.Header().Set("Cache-Control", "max-age=31556926, public")
+		}
+		if strings.HasSuffix(r.URL.Path, "/") {
+			http.NotFound(w, r)
+			return
+		}
+		handler.ServeHTTP(w, r)
+	})
+}
+
 //map should be of minimum required browser version.
 //var browsersNotSupported string = "MSIE/11;Internet Explorer/11;Safari/9;Chrome/43;Edge/15;Firefox/52"
 //var browserMinimumSupported = [6]string{"MSIE/11", "Internet Explorer/11", "Safari/9", "Chrome/43", "Edge/15", "Firefox/52"}