Add "repmgr bdr register"

Makefile.in

@@ -26,7 +26,8 @@ include Makefile.global
 
 $(info Building against PostgreSQL $(MAJORVERSION))
 
-REPMGR_CLIENT_OBJS = repmgr-client.o repmgr-action-primary.o repmgr-action-standby.o repmgr-action-cluster.o \
+REPMGR_CLIENT_OBJS = repmgr-client.o \
+  repmgr-action-primary.o repmgr-action-standby.o repmgr-action-bdr.o repmgr-action-cluster.o \
   config.o log.o strutil.o dbutils.o dirutil.o compat.o controldata.o
 REPMGRD_OBJS = repmgrd.o config.o log.o dbutils.o strutil.o
 
@@ -52,9 +53,10 @@ maintainer-clean: additional-maintainer-clean
 
 additional-clean:
 	rm -f repmgr-client.o
-	rm -f repmgr-action-cluster.o
 	rm -f repmgr-action-primary.o
 	rm -f repmgr-action-standby.o
+	rm -f repmgr-action-bdr.o
+	rm -f repmgr-action-cluster.o
 	rm -f repmgrd.o
 	rm -f compat.o
 	rm -f config.o

README.md

@@ -37,6 +37,8 @@ Currently available:
     repmgr standby promote
     repmgr standby follow
 
+    repmgr bdr register
+
     repmgr cluster event [--all] [--node-id] [--node-name] [--event] [--event-matching]
 
 
@@ -63,3 +65,67 @@ and vice-versa, e.g. to avoid hard-coding things like a node's
 upstream ID which might change.
 
 TODO: possibly add a config file conversion script/function.
+
+Generating event notifications with repmgr/repmgrd
+--------------------------------------------------
+
+Each time `repmgr` or `repmgrd` perform a significant event, a record
+of that event is written into the `repl_events` table together with
+a timestamp, an indication of failure or success, and further details
+if appropriate. This is useful for gaining an overview of events
+affecting the replication cluster. However note that this table has
+advisory character and should be used in combination with the `repmgr`
+and PostgreSQL logs to obtain details of any events.
+
+Example output after a master was registered and a standby cloned
+and registered:
+
+    repmgr=# SELECT * from repmgr_test.repl_events ;
+     node_id |      event       | successful |        event_timestamp        |                                       details
+    ---------+------------------+------------+-------------------------------+-------------------------------------------------------------------------------------
+           1 | master_register  | t          | 2016-01-08 15:04:39.781733+09 |
+           2 | standby_clone    | t          | 2016-01-08 15:04:49.530001+09 | Cloned from host 'repmgr_node1', port 5432; backup method: pg_basebackup; --force: N
+           2 | standby_register | t          | 2016-01-08 15:04:50.621292+09 |
+    (3 rows)
+
+Additionally, event notifications can be passed to a user-defined program
+or script which can take further action, e.g. send email notifications.
+This is done by setting the `event_notification_command` parameter in
+`repmgr.conf`.
+
+This parameter accepts the following format placeholders:
+
+    %n - node ID
+    %e - event type
+    %s - success (1 or 0)
+    %t - timestamp
+    %d - details
+
+The values provided for "%t" and "%d" will probably contain spaces,
+so should be quoted in the provided command configuration, e.g.:
+
+    event_notification_command='/path/to/some/script %n %e %s "%t" "%d"'
+
+Additionally the following format placeholders are available for the even
+type `bdr_failover`:
+
+    %c - conninfo string of the next available node
+    %a - name of the next available node
+
+These should always be quoted.
+
+By default, all notification type will be passed to the designated script;
+the notification types can be filtered to explicitly named ones:
+
+    event_notifications=master_register,standby_register
+
+The following event types are available:
+
+  ...
+  * `bdr_failover`
+  * `bdr_register`
+  * `bdr_unregister`
+
+Note that under some circumstances (e.g. no replication cluster master could
+be located), it will not be possible to write an entry into the `repl_events`
+table, in which case `event_notification_command` can serve as a fallback.

dbutils.c

@@ -47,6 +47,33 @@ parse_lsn(const char *str)
 }
 
 
+/*
+ * Wrap query with appropriate DDL function, if required.
+ */
+void
+wrap_ddl_query(PQExpBufferData *query_buf, int replication_type, const char *fmt, ...)
+{
+	va_list		arglist;
+	char		buf[MAXLEN];
+
+	if (replication_type == REPLICATION_TYPE_BDR)
+	{
+		appendPQExpBuffer(query_buf, "SELECT bdr.bdr_replicate_ddl_command($repmgr$");
+	}
+
+	va_start(arglist, fmt);
+	vsnprintf(buf, MAXLEN, fmt, arglist);
+	va_end(arglist);
+
+	appendPQExpBuffer(query_buf, "%s", buf);
+
+	if (replication_type == REPLICATION_TYPE_BDR)
+	{
+		appendPQExpBuffer(query_buf, "$repmgr$)");
+	}
+}
+
+
 /* ==================== */
 /* Connection functions */
 /* ==================== */
@@ -1517,6 +1544,7 @@ update_node_record(PGconn *conn, char *repmgr_action, t_node_info *node_info)
 	return _create_update_node_record(conn, "update", node_info);
 }
 
+
 static bool
 _create_update_node_record(PGconn *conn, char *action, t_node_info *node_info)
 {
@@ -2793,7 +2821,7 @@ is_bdr_repmgr(PGconn *conn)
 
 
 bool
-is_table_in_bdr_replication_set(PGconn *conn, char *tablename, char *set)
+is_table_in_bdr_replication_set(PGconn *conn, const char *tablename, const char *set)
 {
 	PQExpBufferData		query;
 	PGresult			*res;
@@ -2829,10 +2857,10 @@ is_table_in_bdr_replication_set(PGconn *conn, char *tablename, char *set)
 
 
 bool
-add_table_to_bdr_replication_set(PGconn *conn, char *tablename, char *set)
+add_table_to_bdr_replication_set(PGconn *conn, const char *tablename, const char *set)
 {
 	PQExpBufferData		query;
-	PGresult			*res;
+	PGresult		   *res;
 
 	initPQExpBuffer(&query);
 
@@ -2861,3 +2889,80 @@ add_table_to_bdr_replication_set(PGconn *conn, char *tablename, char *set)
 
 	return true;
 }
+
+
+bool
+bdr_node_exists(PGconn *conn, const char *node_name)
+{
+	PQExpBufferData		query;
+	PGresult		   *res;
+	bool				node_exists;
+
+	initPQExpBuffer(&query);
+
+	appendPQExpBuffer(
+		&query,
+		"SELECT COUNT(*)"
+		"  FROM bdr.bdr_nodes"
+		" WHERE node_name = '%s'",
+		node_name);
+
+	res = PQexec(conn, query.data);
+	termPQExpBuffer(&query);
+
+	if (!res || PQresultStatus(res) != PGRES_TUPLES_OK)
+	{
+		node_exists = false;
+	}
+	else
+	{
+		node_exists = atoi(PQgetvalue(res, 0, 0)) == 1 ? true : false;
+	}
+
+	PQclear(res);
+
+	return node_exists;
+}
+
+
+void
+add_extension_tables_to_bdr_replication_set(PGconn *conn)
+{
+	PQExpBufferData		query;
+	PGresult		   *res;
+
+	initPQExpBuffer(&query);
+
+	appendPQExpBuffer(
+		&query,
+		"    SELECT c.relname "
+		"      FROM pg_class c "
+        "INNER JOIN pg_namespace n "
+		"        ON c.relnamespace = n.oid "
+		"     WHERE n.nspname = 'repmgr' "
+		"       AND c.relkind = 'r' ");
+
+	res = PQexec(conn, query.data);
+	termPQExpBuffer(&query);
+
+	if (!res || PQresultStatus(res) != PGRES_TUPLES_OK)
+	{
+		//
+	}
+	else
+	{
+		int i;
+
+		for (i = 0; i < PQntuples(res); i++)
+		{
+			add_table_to_bdr_replication_set(
+				conn,
+				PQgetvalue(res, i, 0),
+				"repmgr");
+		}
+	}
+
+	PQclear(res);
+
+	return;
+}

dbutils.h

@@ -148,6 +148,8 @@ typedef struct s_connection_user
 
 XLogRecPtr parse_lsn(const char *str);
 
+extern void wrap_ddl_query(PQExpBufferData *query_buf, int replication_type, const char *fmt, ...)
+__attribute__((format(PG_PRINTF_ATTRIBUTE, 3, 4)));
 
 /* connection functions */
 PGconn *establish_db_connection(const char *conninfo,
@@ -268,8 +270,10 @@ XLogRecPtr get_last_wal_receive_location(PGconn *conn);
 
 bool		is_bdr_db(PGconn *conn);
 bool		is_bdr_repmgr(PGconn *conn);
-bool		is_table_in_bdr_replication_set(PGconn *conn, char *tablename, char *set);
+bool		is_table_in_bdr_replication_set(PGconn *conn, const char *tablename, const char *set);
-bool		add_table_to_bdr_replication_set(PGconn *conn, char *tablename, char *set);
+bool		add_table_to_bdr_replication_set(PGconn *conn, const char *tablename, const char *set);
+bool		bdr_node_exists(PGconn *conn, const char *node_name);
+void		add_extension_tables_to_bdr_replication_set(PGconn *conn);
 
 #endif /* dbutils.h */
 

repmgr-action-bdr.c

@@ -0,0 +1,221 @@
+/*
+ * repmgr-action-standby.c
+ *
+ * Implements BDR-related actions for the repmgr command line utility
+ *
+ * Copyright (c) 2ndQuadrant, 2010-2017
+ */
+
+#include "repmgr.h"
+
+#include "repmgr-client-global.h"
+#include "repmgr-action-bdr.h"
+
+
+/*
+ * do_bdr_register()
+ *
+ * As each BDR node is its own master, registering a BDR node
+ * will create the repmgr metadata schema if necessary.
+ */
+void
+do_bdr_register(void)
+{
+	PGconn	   	   *conn = NULL;
+    ExtensionStatus extension_status;
+	t_node_info		node_info = T_NODE_INFO_INITIALIZER;
+	RecordStatus	record_status;
+	PQExpBufferData event_details;
+	bool	   	    success = true;
+
+	/* sanity-check configuration for BDR-compatability */
+	if (config_file_options.replication_type != REPLICATION_TYPE_BDR)
+	{
+		log_error(_("cannot run BDR REGISTER on a non-BDR node"));
+		exit(ERR_BAD_CONFIG);
+	}
+
+	conn = establish_db_connection(config_file_options.conninfo, true);
+
+	if (!is_bdr_db(conn))
+	{
+		/* TODO: name database */
+		log_error(_("database is not BDR-enabled"));
+		log_hint(_("when using repmgr with BDR, the repmgr schema must be stored in the BDR database"));
+		exit(ERR_BAD_CONFIG);
+	}
+
+	/* check whether repmgr extension exists, and that any other nodes are BDR */
+	extension_status = get_repmgr_extension_status(conn);
+
+	if (extension_status == REPMGR_UNKNOWN)
+	{
+		log_error(_("unable to determine status of \"repmgr\" extension"));
+		PQfinish(conn);
+	}
+
+
+	if (extension_status == REPMGR_UNAVAILABLE)
+	{
+		log_error(_("\"repmgr\" extension is not available"));
+		PQfinish(conn);
+	}
+
+	if (extension_status == REPMGR_INSTALLED)
+	{
+		if (!is_bdr_repmgr(conn))
+		{
+			log_error(_("repmgr metadatabase contains records for non-BDR nodes"));
+			exit(ERR_BAD_CONFIG);
+		}
+	}
+	else
+	{
+		//log_info(_("bdr register: creating database objects inside the %s schema"),
+		//			 get_repmgr_schema());
+
+		begin_transaction(conn);
+
+		if (!create_repmgr_extension(conn))
+		{
+			log_error(_("unable to create repmgr extension - see preceding error message(s); aborting"));
+			rollback_transaction(conn);
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		commit_transaction(conn);
+	}
+
+	/* 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\n"));
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+	}
+
+	initPQExpBuffer(&event_details);
+
+	begin_transaction(conn);
+
+	/*
+	 * we'll check if a record exists (even if the schema was just created),
+	 * as there's a faint chance of a race condition
+	 */
+
+	record_status = get_node_record(conn, config_file_options.node_id, &node_info);
+
+	/* Update internal node record */
+
+	node_info.type = BDR;
+	node_info.node_id = config_file_options.node_id;
+	node_info.upstream_node_id = NO_UPSTREAM_NODE;
+	node_info.active = true;
+	node_info.priority = config_file_options.priority;
+
+	strncpy(node_info.node_name, config_file_options.node_name, MAXLEN);
+	strncpy(node_info.location, config_file_options.location, MAXLEN);
+	strncpy(node_info.conninfo, config_file_options.conninfo, MAXLEN);
+
+	if (record_status == RECORD_FOUND)
+	{
+		bool node_updated;
+		/*
+		 * At this point we will have established there are no non-BDR records,
+		 * so no need to verify the node type
+		 */
+		if (!runtime_options.force)
+		{
+			log_error(_("this node is already registered"));
+			log_hint(_("use -F/--force to overwrite the existing node record"));
+			rollback_transaction(conn);
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		/*
+		 * don't permit changing the node name - this must match the
+		 * BDR node name set when the node was registered.
+		 */
+
+		if (strncmp(node_info.node_name, config_file_options.node_name, MAXLEN) != 0)
+		{
+			log_error(_("a record for node %i is already registered with node_name '%s'"),
+					  config_file_options.node_id, node_info.node_name);
+			log_hint(_("node_name configured in repmgr.conf is '%s'"), config_file_options.node_name);
+
+			rollback_transaction(conn);
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		node_updated = update_node_record(conn, "bdr register", &node_info);
+
+		if (node_updated == true)
+		{
+			appendPQExpBuffer(&event_details, _("node record updated for node '%s' (%i)"),
+							  config_file_options.node_name, config_file_options.node_id);
+			log_verbose(LOG_NOTICE, "%s\n", event_details.data);
+		}
+		{
+			success = false;
+		}
+
+	}
+	else
+	{
+		/* create new node record */
+		bool node_created = create_node_record(conn, "bdr register", &node_info);
+
+		if (node_created == true)
+		{
+			appendPQExpBuffer(&event_details,
+							  _("node record created for node '%s' (ID: %i)"),
+							  config_file_options.node_name, config_file_options.node_id);
+			log_notice("%s", event_details.data);
+		}
+		else
+		{
+			success = false;
+		}
+	}
+
+	if (success == false)
+	{
+		rollback_transaction(conn);
+		PQfinish(conn);
+		exit(ERR_DB_QUERY);
+	}
+
+	commit_transaction(conn);
+	/* Log the event */
+	create_event_notification(
+		conn,
+		&config_file_options,
+		config_file_options.node_id,
+		"bdr_register",
+		true,
+		event_details.data);
+
+	termPQExpBuffer(&event_details);
+
+	PQfinish(conn);
+
+	log_notice(_("BDR node %i registered (conninfo: %s)"),
+			   config_file_options.node_id, config_file_options.conninfo);
+
+	return;
+}
+
+
+void
+do_bdr_unregister(void)
+{
+	return;
+}

repmgr-action-bdr.h

@@ -0,0 +1,13 @@
+/*
+ * repmgr-action-bdr.h
+ * Copyright (c) 2ndQuadrant, 2010-2017
+ */
+
+#ifndef _REPMGR_ACTION_BDR_H_
+#define _REPMGR_ACTION_BDR_H_
+
+extern void do_bdr_register(void);
+extern void do_bdr_unregister(void);
+
+
+#endif /* _REPMGR_ACTION_BDR_H_ */

repmgr-action-standby.h

@@ -33,4 +33,4 @@ typedef struct
 #define T_CONFIGFILE_LIST_INITIALIZER { 0, 0, NULL }
 
 
-#endif
+#endif /* _REPMGR_ACTION_STANDBY_H_ */

repmgr-client.c

@@ -28,6 +28,8 @@
 #include "repmgr-client-global.h"
 #include "repmgr-action-primary.h"
 #include "repmgr-action-standby.h"
+#include "repmgr-action-bdr.h"
+
 #include "repmgr-action-cluster.h"
 
 #include <storage/fd.h>         /* for PG_TEMP_FILE_PREFIX */
@@ -579,6 +581,7 @@ main(int argc, char **argv)
 			else if (strcasecmp(repmgr_action, "UNREGISTER") == 0)
 				action = PRIMARY_UNREGISTER;
 		}
+
 		else if (strcasecmp(repmgr_node_type, "STANDBY") == 0)
 		{
 			if (strcasecmp(repmgr_action, "CLONE") == 0)
@@ -599,6 +602,14 @@ main(int argc, char **argv)
 				action = STANDBY_RESTORE_CONFIG;
 		}
 
+		else if (strcasecmp(repmgr_node_type, "BDR") == 0)
+		{
+			if (strcasecmp(repmgr_action, "REGISTER") == 0)
+				action = BDR_REGISTER;
+			else if (strcasecmp(repmgr_action, "UNREGISTER") == 0)
+				action = BDR_UNREGISTER;
+		}
+
 		else if (strcasecmp(repmgr_node_type, "CLUSTER") == 0)
 		{
 			if (strcasecmp(repmgr_action, "EVENT") == 0)
@@ -845,6 +856,7 @@ main(int argc, char **argv)
 
 	switch (action)
 	{
+		/* PRIMARY */
 		case PRIMARY_REGISTER:
 			do_primary_register();
 			break;
@@ -852,6 +864,7 @@ main(int argc, char **argv)
 			do_primary_unregister();
 			break;
 
+		/* STANDBY */
 		case STANDBY_CLONE:
 			do_standby_clone();
 			break;
@@ -877,6 +890,15 @@ main(int argc, char **argv)
 			do_standby_restore_config();
 			break;
 
+		/* BDR */
+		case BDR_REGISTER:
+			do_bdr_register();
+			break;
+		case BDR_UNREGISTER:
+			do_bdr_unregister();
+			break;
+
+		/* CLUSTER */
 		case CLUSTER_EVENT:
 			do_cluster_event();
 			break;
@@ -1336,14 +1358,14 @@ create_repmgr_extension(PGconn *conn)
 	/* 4. Create extension */
 	initPQExpBuffer(&query);
 
-	appendPQExpBuffer(&query,
+	wrap_ddl_query(&query, config_file_options.replication_type,
-					  "CREATE EXTENSION repmgr");
+				   "CREATE EXTENSION repmgr");
 
 	res = PQexec(schema_create_conn, query.data);
 
 	termPQExpBuffer(&query);
 
-	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	if ((PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK))
 	{
 		log_error(_("unable to create \"repmgr\" extension:\n  %s"),
 				  PQerrorMessage(schema_create_conn));
@@ -1357,14 +1379,21 @@ create_repmgr_extension(PGconn *conn)
 
 	PQclear(res);
 
+	/* For BDR, we'll need to add the repmgr extension tables to a replication set */
+	if (config_file_options.replication_type == REPLICATION_TYPE_BDR)
+	{
+		add_extension_tables_to_bdr_replication_set(conn);
+	}
+
 	/* 5. If not superuser, grant usage */
 	if (is_superuser == false)
 	{
 		initPQExpBuffer(&query);
 
-		appendPQExpBuffer(&query,
+		wrap_ddl_query(&query, config_file_options.replication_type,
-						  "GRANT USAGE ON SCHEMA repmgr TO %s",
+					   "GRANT USAGE ON SCHEMA repmgr TO %s",
-						  userinfo.username);
+					   userinfo.username);
+
 		res = PQexec(schema_create_conn, query.data);
 
 		termPQExpBuffer(&query);
@@ -1382,9 +1411,10 @@ create_repmgr_extension(PGconn *conn)
 		}
 
 		initPQExpBuffer(&query);
-		appendPQExpBuffer(&query,
+		wrap_ddl_query(&query, config_file_options.replication_type,
-						  "GRANT ALL ON ALL TABLES IN SCHEMA repmgr TO %s",
+					   "GRANT ALL ON ALL TABLES IN SCHEMA repmgr TO %s",
-						  userinfo.username);
+					   userinfo.username);
+
 		res = PQexec(schema_create_conn, query.data);
 
 		termPQExpBuffer(&query);