mgmtd: clarify the startup dance in comments

Also retry the config read vs. aborting if we haven't got a FE client connection yet. Signed-off-by: Christian Hopps <[email protected]>
FRRouting · Oct 12, 2023 · f560807 · f560807
1 parent 11e8c90
commit f560807
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Showing 2 changed files with 21 additions and 5 deletions.
diff --git a/mgmtd/mgmt.c b/mgmtd/mgmt.c
@@ -52,17 +52,26 @@ void mgmt_init(void)
 	/* Initialize the MGMTD Frontend Adapter Module */
 	mgmt_fe_adapter_init(mm->master);
 
-	/* Initialize the CLI frontend client */
+	/*
+	 * Initialize the CLI frontend client -- this queues an event for the
+	 * client to short-circuit connect to the server (ourselves).
+	 */
 	vty_init_mgmt_fe();
 
-	/* MGMTD VTY commands installation. */
+	/*
+	 * MGMTD VTY commands installation -- the frr lib code will queue an
+	 * event to read the config files which needs to happen after the
+	 * connect from above is made.
+	 */
 	mgmt_vty_init();
 
 	/*
 	 * Initialize the MGMTD Backend Adapter Module
 	 *
-	 * We do this after the FE stuff so that we always read our config file
-	 * prior to any BE connection.
+	 * We do this after the FE stuff so that we have read our config file
+	 * prior to any BE connection. Setting up the server will queue a
+	 * "socket read" event to accept BE connections. So the code is counting
+	 * on the above 2 events to run prior to any `accept` event from here.
 	 */
 	mgmt_be_adapter_init(mm->master);
 }

diff --git a/mgmtd/mgmt_vty.c b/mgmtd/mgmt_vty.c
@@ -452,7 +452,14 @@ DEFPY(debug_mgmt, debug_mgmt_cmd,
 
 static void mgmt_config_read_in(struct event *event)
 {
-	mgmt_vty_read_configs();
+	if (vty_mgmt_fe_enabled())
+		mgmt_vty_read_configs();
+	else {
+		zlog_warn("%s: no connection to front-end server, retry in 1s",
+			  __func__);
+		event_add_timer(mm->master, mgmt_config_read_in, NULL, 1,
+				&mgmt_daemon_info->read_in);
+	}
 }
 
 void mgmt_vty_init(void)