MM-32133 shared channel username collisions (#17347)

Support for handling username collisions between remote clusters. Users belonging to remote clusters have their username changed to include the remote name e.g. wiggin becomes wiggin:mattermost.

@mentions are also modified so the munged username is replaced with the original username when the post is sync'd with the remote the user belongs to.

When adding remote users:
- append the remote name to the username with colon separator
- append the remote name to the email address with colon separator
- store the original username and email address in user props
- when resolving @mentions replace with the stored original username

services/remotecluster/invitation.go

@@ -12,11 +12,12 @@ import (
 )
 
 // AcceptInvitation is called when accepting an invitation to connect with a remote cluster.
-func (rcs *Service) AcceptInvitation(invite *model.RemoteClusterInvite, name string, creatorId string, teamId string, siteURL string) (*model.RemoteCluster, error) {
+func (rcs *Service) AcceptInvitation(invite *model.RemoteClusterInvite, name string, displayName, creatorId string, teamId string, siteURL string) (*model.RemoteCluster, error) {
 	rc := &model.RemoteCluster{
 		RemoteId:     invite.RemoteId,
 		RemoteTeamId: invite.RemoteTeamId,
-		DisplayName:  name,
+		Name:         name,
+		DisplayName:  displayName,
 		Token:        model.NewId(),
 		RemoteToken:  invite.Token,
 		SiteURL:      invite.SiteURL,

services/remotecluster/send_test.go

@@ -177,14 +177,14 @@ func makeRemoteClusters(num int, siteURL string) []*model.RemoteCluster {
 
 func makeRemoteCluster(name string, siteURL string, topics string) *model.RemoteCluster {
 	return &model.RemoteCluster{
-		RemoteId:    model.NewId(),
-		DisplayName: name,
-		SiteURL:     siteURL,
-		Token:       model.NewId(),
-		Topics:      topics,
-		CreateAt:    model.GetMillis(),
-		LastPingAt:  model.GetMillis(),
-		CreatorId:   model.NewId(),
+		RemoteId:   model.NewId(),
+		Name:       name,
+		SiteURL:    siteURL,
+		Token:      model.NewId(),
+		Topics:     topics,
+		CreateAt:   model.GetMillis(),
+		LastPingAt: model.GetMillis(),
+		CreatorId:  model.NewId(),
 	}
 }
 

services/remotecluster/sendmsg.go

@@ -84,7 +84,9 @@ func (rcs *Service) sendMsg(task sendMsgTask) {
 	defer func() {
 		if r := recover(); r != nil {
 			rcs.server.GetLogger().Log(mlog.LvlRemoteClusterServiceError, "Remote Cluster sendMsg panic",
-				mlog.String("remote", task.rc.DisplayName), mlog.String("msgId", task.msg.Id), mlog.Any("panic", r))
+				mlog.String("remote", task.rc.DisplayName),
+				mlog.String("msgId", task.msg.Id), mlog.Any("panic", r),
+			)
 		}
 
 		if errResp != nil {

services/remotecluster/service.go

@@ -63,7 +63,7 @@ type RemoteClusterServiceIFace interface {
 	RemoveConnectionStateListener(listenerId string)
 	SendMsg(ctx context.Context, msg model.RemoteClusterMsg, rc *model.RemoteCluster, f SendMsgResultFunc) error
 	SendFile(ctx context.Context, us *model.UploadSession, fi *model.FileInfo, rc *model.RemoteCluster, rp ReaderProvider, f SendFileResultFunc) error
-	AcceptInvitation(invite *model.RemoteClusterInvite, name string, creatorId string, teamId string, siteURL string) (*model.RemoteCluster, error)
+	AcceptInvitation(invite *model.RemoteClusterInvite, name string, displayName string, creatorId string, teamId string, siteURL string) (*model.RemoteCluster, error)
 	ReceiveIncomingMsg(rc *model.RemoteCluster, msg model.RemoteClusterMsg) Response
 }