Don't log websocket messages if there are errors.

The messages that come over the websockets can potentially contain sensitive
information that shouldn't be put in logs. Separately, if reading the message
results in an error, the content of the message is irrelevant and unreliable.

agent/acs/handler/acs_handler.go

@@ -214,7 +214,7 @@ func (acsSession *session) Start() error {
 				// Disconnected unexpectedly from ACS, compute backoff duration to
 				// reconnect
 				reconnectDelay := acsSession.computeReconnectDelay(isInactiveInstance)
-				seelog.Debugf("Reconnecting to ACS in: %v", reconnectDelay)
+				seelog.Infof("Reconnecting to ACS in: %s", reconnectDelay.String())
 				waitComplete := acsSession.waitForDuration(reconnectDelay)
 				if waitComplete {
 					// If the context was not cancelled and we've waited for the

agent/wsclient/client.go

@@ -338,7 +338,7 @@ func (cs *ClientServerImpl) ConsumeMessages() error {
 
 		default:
 			// Unexpected error occurred
-			seelog.Errorf("Error getting message from ws backend: error: [%v], message: [%s], messageType: [%v] ", err, message, messageType)
+			seelog.Errorf("Error getting message from ws backend: error: [%v], messageType: [%v] ", err, messageType)
 			return err
 		}
 
@@ -413,8 +413,8 @@ func websocketScheme(httpScheme string) (string, error) {
 // See https://github.com/gorilla/websocket/blob/87f6f6a22ebfbc3f89b9ccdc7fddd1b914c095f9/conn.go#L650
 func permissibleCloseCode(err error) bool {
 	return websocket.IsCloseError(err,
-		websocket.CloseNormalClosure,
-		websocket.CloseAbnormalClosure,
-		websocket.CloseGoingAway,
-		websocket.CloseInternalServerErr)
+		websocket.CloseNormalClosure,     // websocket error code 1000
+		websocket.CloseAbnormalClosure,   // websocket error code 1006
+		websocket.CloseGoingAway,         // websocket error code 1001
+		websocket.CloseInternalServerErr) // websocket error code 1011
 }