From 0a1addfdc0e55e128b831199ccfe1710167d692a Mon Sep 17 00:00:00 2001
From: Ian Barwick <barwick@gmail.com>
Date: Wed, 12 Jul 2017 09:03:15 +0900
Subject: [PATCH] When registering a BDR node, sync repmgr.nodes from another
 node

If a BDR node is added via bdr_group_join(), repmgr.nodes will
start off empty, so we'll need to sync it ourselves before adding
it to the repmgr replication set.
---
 dbutils.c           | 27 ++++++++++++++++++++++-
 dbutils.h           |  1 +
 repmgr-action-bdr.c | 52 +++++++++++++++++++++++++++++++++------------
 3 files changed, 66 insertions(+), 14 deletions(-)

diff --git a/dbutils.c b/dbutils.c
index c4486820..26c84010 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -1436,6 +1436,30 @@ void _populate_node_records(PGresult *res, NodeInfoList *node_list)
 }
 
 
+void
+get_all_node_records(PGconn *conn, NodeInfoList *node_list)
+{
+	PQExpBufferData	query;
+	PGresult   *res;
+
+	initPQExpBuffer(&query);
+
+	appendPQExpBuffer(&query,
+					  "  SELECT node_id, type, upstream_node_id, node_name, conninfo, repluser, slot_name, location, priority, active"
+					  "    FROM repmgr.nodes "
+					  "ORDER BY node_id ");
+
+	log_verbose(LOG_DEBUG, "get_all_node_records():\n%s", query.data);
+
+	res = PQexec(conn, query.data);
+
+	termPQExpBuffer(&query);
+
+	_populate_node_records(res, node_list);
+
+	return;
+}
+
 void
 get_downstream_node_records(PGconn *conn, int node_id, NodeInfoList *node_list)
 {
@@ -2996,7 +3020,8 @@ get_bdr_init_node_record(PGconn *conn, t_bdr_node_info *node_info)
 
 	if (!res || PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
-		//
+		PQclear(res);
+		return RECORD_NOT_FOUND;
 	}
 	else
 	{
diff --git a/dbutils.h b/dbutils.h
index 757d6722..f8dcdd54 100644
--- a/dbutils.h
+++ b/dbutils.h
@@ -240,6 +240,7 @@ t_node_info *get_node_record_pointer(PGconn *conn, int node_id);
 bool		get_local_node_record(PGconn *conn, int node_id, t_node_info *node_info);
 bool		get_primary_node_record(PGconn *conn, t_node_info *node_info);
 
+void		get_all_node_records(PGconn *conn, NodeInfoList *node_list);
 void		get_downstream_node_records(PGconn *conn, int node_id, NodeInfoList *nodes);
 void		get_active_sibling_node_records(PGconn *conn, int node_id, int upstream_node_id, NodeInfoList *node_list);
 void		get_node_records_by_priority(PGconn *conn, NodeInfoList *node_list);
diff --git a/repmgr-action-bdr.c b/repmgr-action-bdr.c
index c5836d52..4afb2ab6 100644
--- a/repmgr-action-bdr.c
+++ b/repmgr-action-bdr.c
@@ -87,26 +87,52 @@ do_bdr_register(void)
 		commit_transaction(conn);
 	}
 
-	// any other BDR nodes - if so connect to one where "node_init_from_dsn" is null,
-	// and copy repmgr.nodes
-	// (we'll assume all other nodes are up-to-date)
-	// don't copy other tables...
+	/*
+	 * before adding the extension tables to the replication set,
+	 * if any other BDR nodes exist, populate repmgr.nodes with a copy
+	 * of existing entries
+	 *
+	 * currently we won't copy the contents of any other tables
+	 *
+	 */
 	{
-		PGconn *init_node;
-		RecordStatus bdr_record_status;
-		t_bdr_node_info bdr_init_node_info = T_BDR_NODE_INFO_INITIALIZER;
+		NodeInfoList local_node_records = T_NODE_INFO_LIST_INITIALIZER;
+		get_all_node_records(conn, &local_node_records);
 
-		bdr_record_status = get_bdr_init_node_record(conn, &bdr_init_node_info);
-
-		if (bdr_record_status == RECORD_FOUND)
+		if (local_node_records.node_count == 0)
 		{
+			/* XXX get all BDR node records */
+			RecordStatus bdr_record_status;
+			t_bdr_node_info bdr_init_node_info = T_BDR_NODE_INFO_INITIALIZER;
+
+			bdr_record_status = get_bdr_init_node_record(conn, &bdr_init_node_info);
+
+			if (bdr_record_status != RECORD_FOUND)
+			{
+				/* XXX don't assume the original node will still be part of the cluster */
+				log_error(_("unable to retrieve record for originating node"));
+				PQfinish(conn);
+				exit(ERR_BAD_CONFIG);
+			}
+
 			if (strncmp(node_info.node_name, bdr_init_node_info.node_name, MAXLEN) != 0)
 			{
-				init_node = establish_db_connection_quiet(bdr_init_node_info.node_init_from_dsn);
-				
+				/* */
+				PGconn *init_node_conn;
+				NodeInfoList existing_nodes = T_NODE_INFO_LIST_INITIALIZER;
+				NodeInfoListCell *cell;
+
+				init_node_conn = establish_db_connection_quiet(bdr_init_node_info.node_local_dsn);
+
+				/* XXX check repmgr schema exists */
+				get_all_node_records(init_node_conn, &existing_nodes);
+
+				for (cell = existing_nodes.head; cell; cell = cell->next)
+				{
+					create_node_record(conn, "bdr register", cell->node_info);
+				}
 			}
 		}
-
 	}
 
 	/* Add the repmgr extension tables to a replication set */