From c5c86e1ada362861fc93ce91e6364a2cd5dafbe9 Mon Sep 17 00:00:00 2001
From: Ian Barwick <ian@2ndquadrant.com>
Date: Thu, 4 Jan 2018 16:07:06 +0900
Subject: [PATCH] "repmgr bdr register": improve node name check

We'll use "bdr.bdr_get_local_node_name()" to check the local BDR node
name and the repmgr one match.
---
 dbutils.c           | 11 +++++------
 dbutils.h           |  3 +--
 repmgr-action-bdr.c | 46 ++++++++++++++++++++++++++++++++-------------
 3 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/dbutils.c b/dbutils.c
index 61148274..821d56e6 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -4289,7 +4289,7 @@ add_table_to_bdr_replication_set(PGconn *conn, const char *tablename, const char
 
 
 bool
-bdr_node_exists(PGconn *conn, const char *node_name)
+bdr_node_name_matches(PGconn *conn, const char *node_name, PQExpBufferData *bdr_local_node_name)
 {
 	PQExpBufferData query;
 	PGresult   *res = NULL;
@@ -4298,10 +4298,7 @@ bdr_node_exists(PGconn *conn, const char *node_name)
 	initPQExpBuffer(&query);
 
 	appendPQExpBuffer(&query,
-					  "SELECT COUNT(*)"
-					  "  FROM bdr.bdr_nodes"
-					  " WHERE node_name = '%s'",
-					  node_name);
+					  "SELECT bdr.bdr_get_local_node_name() AS node_name");
 
 	res = PQexec(conn, query.data);
 	termPQExpBuffer(&query);
@@ -4312,7 +4309,9 @@ bdr_node_exists(PGconn *conn, const char *node_name)
 	}
 	else
 	{
-		node_exists = atoi(PQgetvalue(res, 0, 0)) == 1 ? true : false;
+		node_exists = true;
+		appendPQExpBuffer(bdr_local_node_name,
+						  "%s", PQgetvalue(res, 0, 0));
 	}
 
 	PQclear(res);
diff --git a/dbutils.h b/dbutils.h
index 37405c3c..4cf232c0 100644
--- a/dbutils.h
+++ b/dbutils.h
@@ -498,8 +498,7 @@ bool		is_bdr_repmgr(PGconn *conn);
 bool		is_table_in_bdr_replication_set(PGconn *conn, const char *tablename, const char *set);
 bool		add_table_to_bdr_replication_set(PGconn *conn, const char *tablename, const char *set);
 void		add_extension_tables_to_bdr_replication_set(PGconn *conn);
-
-bool		bdr_node_exists(PGconn *conn, const char *node_name);
+bool		bdr_node_name_matches(PGconn *conn, const char *node_name, PQExpBufferData *bdr_local_node_name);
 ReplSlotStatus get_bdr_node_replication_slot_status(PGconn *conn, const char *node_name);
 void		get_bdr_other_node_name(PGconn *conn, int node_id, char *name_buf);
 
diff --git a/repmgr-action-bdr.c b/repmgr-action-bdr.c
index f3fe1260..7677bd05 100644
--- a/repmgr-action-bdr.c
+++ b/repmgr-action-bdr.c
@@ -1,5 +1,5 @@
 /*
- * repmgr-action-standby.c
+ * repmgr-action-bdr.c
  *
  * Implements BDR-related actions for the repmgr command line utility
  *
@@ -92,6 +92,38 @@ do_bdr_register(void)
 		exit(ERR_BAD_CONFIG);
 	}
 
+	/* check for a matching BDR node */
+	{
+		PQExpBufferData bdr_local_node_name;
+		bool		node_match = false;
+
+		initPQExpBuffer(&bdr_local_node_name);
+		node_match = bdr_node_name_matches(conn, config_file_options.node_name, &bdr_local_node_name);
+
+		if (node_match == false)
+		{
+			if (strlen(bdr_local_node_name.data))
+			{
+				log_error(_("local node BDR node name is \"%s\", expected: \"%s\""),
+						  bdr_local_node_name.data,
+						  config_file_options.node_name);
+				log_hint(_("\"node_name\" in repmgr.conf must match \"node_name\" in bdr.bdr_nodes"));
+			}
+			else
+			{
+				log_error(_("local node does not report BDR node name"));
+				log_hint(_("ensure this is an active BDR node"));
+			}
+
+			PQfinish(conn);
+			pfree(dbname);
+			termPQExpBuffer(&bdr_local_node_name);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		termPQExpBuffer(&bdr_local_node_name);
+	}
+
 	/* check whether repmgr extension exists, and that any other nodes are BDR */
 	extension_status = get_repmgr_extension_status(conn);
 
@@ -142,18 +174,6 @@ do_bdr_register(void)
 
 	pfree(dbname);
 
-	/* check for a matching BDR node */
-	{
-		bool		node_exists = bdr_node_exists(conn, config_file_options.node_name);
-
-		if (node_exists == false)
-		{
-			log_error(_("no BDR node with node_name \"%s\" found"), config_file_options.node_name);
-			log_hint(_("\"node_name\" in repmgr.conf must match \"node_name\" in bdr.bdr_nodes"));
-			PQfinish(conn);
-			exit(ERR_BAD_CONFIG);
-		}
-	}
 
 	/*
 	 * before adding the extension tables to the replication set, if any other