MM-28861 Marketplace feature flags (#16451)

* Installing plugins specified by feature flags using the marketplace.

* Switch back to using getplugins client.

* Respect disabling automatic installation of pluings.

* pluginid -> plugin_id

* Debug logs for enable plugin error

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/plugin.go

@@ -198,10 +198,13 @@ func (a *App) InitPlugins(pluginDir, webappPluginDir string) {
 	}
 	pluginsEnvironment.SetPrepackagedPlugins(plugins)
 
+	a.installFeatureFlagPlugins()
+
 	// Sync plugin active state when config changes. Also notify plugins.
 	a.Srv().PluginsLock.Lock()
 	a.RemoveConfigListener(a.Srv().PluginConfigListenerId)
 	a.Srv().PluginConfigListenerId = a.AddConfigListener(func(*model.Config, *model.Config) {
+		a.installFeatureFlagPlugins()
 		a.SyncPluginsActiveState()
 		if pluginsEnvironment := a.GetPluginsEnvironment(); pluginsEnvironment != nil {
 			pluginsEnvironment.RunMultiPluginHook(func(hooks plugin.Hooks) bool {
@@ -510,7 +513,8 @@ func (a *App) getRemoteMarketplacePlugin(pluginId, version string) (*model.BaseM
 	}
 
 	filter := a.getBaseMarketplaceFilter()
-	filter.Filter = pluginId
+	filter.PluginId = pluginId
+	filter.ReturnAllVersions = true
 
 	plugin, err := marketplaceClient.GetPlugin(filter, version)
 	if err != nil {
@@ -886,6 +890,47 @@ func (a *App) processPrepackagedPlugin(pluginPath *pluginSignaturePath) (*plugin
 	return plugin, nil
 }
 
+// installFeatureFlagPlugins handles the automatic installation/upgrade of plugins from feature flags
+func (a *App) installFeatureFlagPlugins() {
+	ffControledPlugins := a.Config().FeatureFlags.Plugins()
+
+	// Respect the automatic prepackaged disable setting
+	if !*a.Config().PluginSettings.AutomaticPrepackagedPlugins {
+		return
+	}
+
+	for pluginId, version := range ffControledPlugins {
+		// Skip installing if the plugin has been previously disabled.
+		pluginState := a.Config().PluginSettings.PluginStates[pluginId]
+		if pluginState != nil && !pluginState.Enable {
+			a.Log().Debug("Not auto installing/upgrade because plugin was disabled", mlog.String("plugin_id", pluginId), mlog.String("version", version))
+			continue
+		}
+
+		// Check if we already installed this version as InstallMarketplacePlugin can't handle re-installs well.
+		pluginStatus, err := a.Srv().GetPluginStatus(pluginId)
+		if err == nil && pluginStatus.Version == version {
+			continue
+		}
+
+		if version != "" && version != "control" {
+			_, err := a.InstallMarketplacePlugin(&model.InstallMarketplacePluginRequest{
+				Id:      pluginId,
+				Version: version,
+			})
+			if err != nil {
+				a.Log().Debug("Unable to install plugin from FF manifest", mlog.String("plugin_id", pluginId), mlog.Err(err), mlog.String("version", version))
+			} else {
+				if err := a.EnablePlugin(pluginId); err != nil {
+					a.Log().Debug("Unable to enable plugin installed from feature flag.", mlog.String("plugin_id", pluginId), mlog.Err(err), mlog.String("version", version))
+				} else {
+					a.Log().Debug("Installed and enabled plugin.", mlog.String("plugin_id", pluginId), mlog.String("version", version))
+				}
+			}
+		}
+	}
+}
+
 // getPrepackagedPlugin builds a PrepackagedPlugin from the plugin at the given path, additionally returning the directory in which it was extracted.
 func getPrepackagedPlugin(pluginPath *pluginSignaturePath, pluginFile io.ReadSeeker, tmpDir string) (*plugin.PrepackagedPlugin, string, error) {
 	manifest, pluginDir, appErr := extractPlugin(pluginFile, tmpDir)