Add "standby unregister"

dbutils.c

@@ -1360,6 +1360,37 @@ _create_update_node_record(PGconn *conn, char *action, t_node_info *node_info)
 	return true;
 }
 
+
+bool
+delete_node_record(PGconn *conn, int node)
+{
+	PQExpBufferData	  query;
+	PGresult   *res;
+
+	initPQExpBuffer(&query);
+
+	appendPQExpBuffer(&query,
+					  "DELETE FROM repmgr.nodes "
+					  " WHERE node_id = %d",
+					  node);
+
+	log_verbose(LOG_DEBUG, "delete_node_record():\n  %s", query.data);
+
+	res = PQexec(conn, query.data);
+
+	if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
+	{
+		log_error(_("unable to delete node record:\n  %s"),
+					PQerrorMessage(conn));
+		PQclear(res);
+		return false;
+	}
+
+	PQclear(res);
+	return true;
+
+}
+
 /* ====================== */
 /* event record functions */
 /* ====================== */

dbutils.h

@@ -132,6 +132,8 @@ PGconn *establish_db_connection_by_params(const char *keywords[],
 										  const char *values[],
 										  const bool exit_on_error);
 
+PGconn	   *get_master_connection(PGconn *standby_conn, int *master_id, char *master_conninfo_out);
+
 bool		is_superuser_connection(PGconn *conn, t_connection_user *userinfo);
 
 /* conninfo manipulation functions */
@@ -164,7 +166,6 @@ bool		get_pg_setting(PGconn *conn, const char *setting, char *output);
 bool		get_cluster_size(PGconn *conn, char *size);
 int			get_server_version(PGconn *conn, char *server_version);
 int			is_standby(PGconn *conn);
-PGconn	   *get_master_connection(PGconn *standby_conn, int *master_id, char *master_conninfo_out);
 int			get_master_node_id(PGconn *conn);
 
 /* extension functions */
@@ -182,6 +183,7 @@ int			get_node_record_by_name(PGconn *conn, const char *node_name, t_node_info *
 
 bool		create_node_record(PGconn *conn, char *repmgr_action, t_node_info *node_info);
 bool		update_node_record(PGconn *conn, char *repmgr_action, t_node_info *node_info);
+bool		delete_node_record(PGconn *conn, int node);
 
 /* event record functions */
 bool        create_event_record(PGconn *conn, t_configuration_options *options, int node_id, char *event, bool successful, char *details);

repmgr-action-standby.c

@@ -930,6 +930,88 @@ do_standby_register(void)
 }
 
 
+void
+do_standby_unregister(void)
+{
+	PGconn	   *conn;
+	PGconn	   *master_conn;
+
+	int 		target_node_id;
+	t_node_info node_info = T_NODE_INFO_INITIALIZER;
+
+	bool		node_record_deleted;
+
+	log_info(_("connecting to local standby"));
+	conn = establish_db_connection(config_file_options.conninfo, true);
+
+	/* check if there is a master in this cluster */
+	log_info(_("connecting to master database"));
+
+	master_conn = get_master_connection(conn, NULL, NULL);
+
+	if (PQstatus(master_conn) != CONNECTION_OK)
+	{
+		log_error(_("unable to connect to master server"));
+		log_detail("%s", PQerrorMessage(conn));
+		exit(ERR_BAD_CONFIG);
+	}
+
+	/*
+	 * if --node-id was specified, unregister that node rather than the
+	 * current one - this enables inactive nodes to be unregistered.
+	 */
+	if (runtime_options.node_id != UNKNOWN_NODE_ID)
+		target_node_id = runtime_options.node_id;
+	else
+		target_node_id = config_file_options.node_id;
+
+	/* Check node exists and is really a standby */
+
+	if (!get_node_record(master_conn, target_node_id, &node_info))
+	{
+		log_error(_("no record found for node %i"), target_node_id);
+		PQfinish(master_conn);
+		PQfinish(conn);
+		exit(ERR_BAD_CONFIG);
+	}
+
+	if (node_info.type != STANDBY)
+	{
+		log_error(_("node %i is not a standby server"), target_node_id);
+		PQfinish(master_conn);
+		PQfinish(conn);
+		exit(ERR_BAD_CONFIG);
+	}
+
+	/* Now unregister the standby */
+	log_notice(_("unregistering node %i"), target_node_id);
+	node_record_deleted = delete_node_record(master_conn,
+										     target_node_id);
+
+	if (node_record_deleted == false)
+	{
+		PQfinish(master_conn);
+		PQfinish(conn);
+		exit(ERR_BAD_CONFIG);
+	}
+
+	/* Log the event */
+	create_event_record(master_conn,
+						&config_file_options,
+						target_node_id,
+						"standby_unregister",
+						true,
+						NULL);
+
+	PQfinish(master_conn);
+	PQfinish(conn);
+
+	log_info(_("standby unregistration complete"));
+
+	return;
+
+}
+
 static void
 check_source_server()
 {

repmgr-action-standby.h

@@ -8,6 +8,7 @@
 
 extern void do_standby_clone(void);
 extern void do_standby_register(void);
+extern void do_standby_unregister(void);
 
 typedef struct
 {

repmgr-client.c

@@ -11,7 +11,8 @@
  * [ MASTER | PRIMARY ] REGISTER
  *
  * STANDBY CLONE
- * STANDBY REGISTER (wip)
+ * STANDBY REGISTER
+ * STANDBY UNREGISTER (wip)
  *
  * CLUSTER EVENT
  */
@@ -558,6 +559,8 @@ main(int argc, char **argv)
 				action = STANDBY_CLONE;
 			else if(strcasecmp(repmgr_action, "REGISTER") == 0)
 				action = STANDBY_REGISTER;
+			else if(strcasecmp(repmgr_action, "UNREGISTER") == 0)
+				action = STANDBY_UNREGISTER;
 		}
 
 		else if(strcasecmp(repmgr_node_type, "CLUSTER") == 0)
@@ -814,6 +817,9 @@ main(int argc, char **argv)
 		case STANDBY_REGISTER:
 			do_standby_register();
 			break;
+		case STANDBY_UNREGISTER:
+			do_standby_unregister();
+			break;
 
 		case CLUSTER_EVENT:
 			do_cluster_event();