Plugin API for Shared Channels: support auto invite (#25834)

* option for auto inviting plugin to all shared channels.

* auto-invite remotes to shared channels when flag set

* fix unit test

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/platform/services/remotecluster/ping.go

@@ -45,7 +45,7 @@ func (rcs *Service) pingGenerator(pingChan chan *model.RemoteCluster, done <-cha
 		}
 
 		for _, rc := range remotes {
-			if rc.SiteURL != "" { // filter out unconfirmed invites
+			if rc.SiteURL != "" || rc.PluginID != "" { // filter out unconfirmed invites
 				pingChan <- rc
 			}
 		}

server/platform/services/sharedchannel/sync_send.go

@@ -248,6 +248,16 @@ func (scs *Service) processTask(task syncTask) error {
 		if err != nil {
 			return err
 		}
+
+		// add all remotes that have the autoinvited option.
+		filter = model.RemoteClusterQueryFilter{
+			RequireOptions: model.BitflagOptionAutoInvited,
+		}
+		remotesAutoInvited, err := scs.server.GetStore().RemoteCluster().GetAll(filter)
+		if err != nil {
+			return err
+		}
+		remotes = append(remotes, remotesAutoInvited...)
 	} else {
 		rc, err := scs.server.GetStore().RemoteCluster().Get(task.remoteID)
 		if err != nil {

server/platform/services/sharedchannel/sync_send_remote.go

@@ -79,7 +79,22 @@ func (scs *Service) syncForRemote(task syncTask, rc *model.RemoteCluster) error
 	}
 
 	scr, err := scs.server.GetStore().SharedChannel().GetRemoteByIds(task.channelID, rc.RemoteId)
-	if err != nil {
+	if isNotFoundError(err) && rc.IsOptionFlagSet(model.BitflagOptionAutoInvited) {
+		// if SharedChannelRemote not found and remote has autoinvite flag, create a scr for it, thus inviting the remote.
+		scr = &model.SharedChannelRemote{
+			Id:                model.NewId(),
+			ChannelId:         task.channelID,
+			CreatorId:         rc.CreatorId,
+			IsInviteAccepted:  true,
+			IsInviteConfirmed: true,
+			RemoteId:          rc.RemoteId,
+			LastPostCreateAt:  model.GetMillis(),
+			LastPostUpdateAt:  model.GetMillis(),
+		}
+		if scr, err = scs.server.GetStore().SharedChannel().SaveRemote(scr); err != nil {
+			return fmt.Errorf("cannot auto-create shared channel remote (channel_id=%s, remote_id=%s): %w", task.channelID, rc.RemoteId, err)
+		}
+	} else if err != nil {
 		return err
 	}
 

server/platform/services/sharedchannel/util.go

@@ -105,6 +105,10 @@ func mungEmail(remotename string, maxLen int) string {
 }
 
 func isConflictError(err error) (string, bool) {
+	if err == nil {
+		return "", false
+	}
+
 	var errConflict *store.ErrConflict
 	if errors.As(err, &errConflict) {
 		return strings.ToLower(errConflict.Resource), true
@@ -117,3 +121,12 @@ func isConflictError(err error) (string, bool) {
 	}
 	return "", false
 }
+
+func isNotFoundError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	var errNotFound *store.ErrNotFound
+	return errors.As(err, &errNotFound)
+}