Fixed Xds-server re-connection.

Add a callback on XDS-Server connect in order to properly register to
XDS Server events in all cases (IOW on reconnection).

Signed-off-by: Sebastien Douheret <sebastien.douheret@iot.bzh>

3 files changed, 49 insertions, 31 deletions

diff --git a/lib/agent/apiv1.go b/lib/agent/apiv1.go
index d0e5a1c..a66f451 100644
--- a/lib/agent/apiv1.go
+++ b/lib/agent/apiv1.go
@@ -117,6 +117,30 @@ func (s *APIService) AddXdsServer(cfg xdsconfig.XDSServerConf) (*XdsServer, erro
 
 		// Declare passthrough routes
 		s.sdksPassthroughInit(svr)
+
+		// Register callback on Connection
+		svr.ConnectOn(func(server *XdsServer) error {
+
+			// Add server to list
+			s.xdsServers[server.ID] = svr
+
+			// Register event forwarder
+			if err := s.sdksEventsForwardInit(server); err != nil {
+				s.Log.Errorf("XDS Server %v - sdk event forwarding error: %v", server.ID, err)
+			}
+
+			// Load projects
+			if err := s.projects.Init(server); err != nil {
+				s.Log.Errorf("XDS Server %v - project init error: %v", server.ID, err)
+			}
+
+			// Registered to all events
+			if err := server.EventRegister(xsapiv1.EVTAll, ""); err != nil {
+				s.Log.Errorf("XDS Server %v - register all events error: %v", server.ID, err)
+			}
+
+			return nil
+		})
 	}
 
 	// Established connection
@@ -127,24 +151,6 @@ func (s *APIService) AddXdsServer(cfg xdsconfig.XDSServerConf) (*XdsServer, erro
 		delete(s.xdsServers, cfg.ID)
 	}
 
-	// Add to map
-	s.xdsServers[svr.ID] = svr
-
-	// Register event forwarder
-	s.sdksEventsForwardInit(svr)
-
-	// Load projects
-	if err == nil && svr.Connected {
-		err = s.projects.Init(svr)
-	}
-
-	// Registered to all events
-	if err == nil && svr.Connected {
-		if err = svr.EventRegister(xsapiv1.EVTAll, ""); err != nil {
-			s.Log.Errorf("XDS Server %v - register all events error: %v", svr.ID, err)
-		}
-	}
-
 	return svr, err
 }
 
diff --git a/lib/agent/projects.go b/lib/agent/projects.go
index 7393364..4e8b0f6 100644
--- a/lib/agent/projects.go
+++ b/lib/agent/projects.go
@@ -54,6 +54,7 @@ func NewProjects(ctx *Context, st *st.SyncThing) *Projects {
 
 // Init Load Projects configuration
 func (p *Projects) Init(server *XdsServer) error {
+
 	svrList := make(map[string]*XdsServer)
 	// If server not set, load for all servers
 	if server == nil {
diff --git a/lib/agent/xdsserver.go b/lib/agent/xdsserver.go
index 3ec6123..346bdb9 100644
--- a/lib/agent/xdsserver.go
+++ b/lib/agent/xdsserver.go
@@ -54,16 +54,20 @@ type XdsServer struct {
 	sockEventsLock *sync.Mutex
 
 	// Private fields
-	client    *common.HTTPClient
-	ioSock    *sio_client.Client
-	logOut    io.Writer
-	apiRouter *gin.RouterGroup
-	cmdList   map[string]interface{}
+	client      *common.HTTPClient
+	ioSock      *sio_client.Client
+	logOut      io.Writer
+	apiRouter   *gin.RouterGroup
+	cmdList     map[string]interface{}
+	cbOnConnect OnConnectedCB
 }
 
 // EventCB Event emitter callback
 type EventCB func(privData interface{}, evtData interface{}) error
 
+// OnConnectedCB connect callback
+type OnConnectedCB func(svr *XdsServer) error
+
 // caller Used to chain event listeners
 type caller struct {
 	id          uuid.UUID
@@ -135,6 +139,12 @@ func (xs *XdsServer) Connect() error {
 	return err
 }
 
+// ConnectOn Register a callback on events reception
+func (xs *XdsServer) ConnectOn(f OnConnectedCB) error {
+	xs.cbOnConnect = f
+	return nil
+}
+
 // IsTempoID returns true when server as a temporary id
 func (xs *XdsServer) IsTempoID() bool {
 	return strings.HasPrefix(xs.ID, _IDTempoPrefix)
@@ -536,15 +546,10 @@ func (xs *XdsServer) _CreateConnectHTTP() error {
 
 // _Reconnect Re-established connection
 func (xs *XdsServer) _Reconnect() error {
+
+	// Note that ConnectOn callback will be called (see apiv1.go file)
 	err := xs._Connect(true)
-	if err == nil {
-		// Reload projects list for this server
-		err = xs.projects.Init(xs)
-	}
-	if err == nil {
-		// Register again to all events
-		err = xs.EventRegister(xsapiv1.EVTAll, "")
-	}
+
 	return err
 }
 
@@ -575,6 +580,12 @@ func (xs *XdsServer) _Connect(reConn bool) error {
 	}
 
 	xs.Connected = true
+
+	// Call OnConnect callback
+	if xs.cbOnConnect != nil {
+		xs.cbOnConnect(xs)
+	}
+
 	xs._NotifyState()
 	return nil
 }