From 50b82f785e9b72270f00f9474df37ae2ea1ce779 Mon Sep 17 00:00:00 2001
From: Ian Barwick <barwick@gmail.com>
Date: Fri, 11 Aug 2017 22:01:02 +0900
Subject: [PATCH] Add function to execute "IDENTIFY_SYSTEM"

---
 dbutils.c            | 22 ++++++++++++++++++++++
 dbutils.h            | 12 ++++++++++++
 repmgr-action-node.c | 22 ++++++++++++++++++++++
 repmgr.h             |  1 +
 4 files changed, 57 insertions(+)

diff --git a/dbutils.c b/dbutils.c
index 93b7449f..849f4d23 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -1442,6 +1442,28 @@ get_replication_lag_seconds(PGconn *conn)
 }
 
 
+bool
+identify_system(PGconn *replconn, t_system_identification *identification)
+{
+	PGresult		 *res;
+
+	res = PQexec(replconn, "IDENTIFY_SYSTEM;");
+
+	if (PQresultStatus(res) != PGRES_TUPLES_OK || !PQntuples(res))
+	{
+		PQclear(res);
+		return false;
+	}
+
+	strncpy(identification->systemid, PQgetvalue(res, 0, 0), MAXLEN);
+	identification->timeline  = atoi(PQgetvalue(res, 0, 1));
+	identification->xlogpos = parse_lsn(PQgetvalue(res, 0, 2));
+
+	PQclear(res);
+	return true;
+}
+
+
 /* ================ */
 /* result functions */
 /* ================ */
diff --git a/dbutils.h b/dbutils.h
index 2bd2123a..006426f2 100644
--- a/dbutils.h
+++ b/dbutils.h
@@ -264,7 +264,18 @@ typedef struct
 
 #define T_CONFIGFILE_LIST_INITIALIZER { 0, 0, NULL }
 
+typedef struct
+{
+	char	   systemid[MAXLEN];
+	int		   timeline;
+	XLogRecPtr xlogpos;
+} t_system_identification;
 
+#define T_SYSTEM_IDENTIFICATION_INITIALIZER { \
+    "", \
+    UNKNOWN_TIMELINE_ID, \
+	InvalidXLogRecPtr \
+}
 /* global variables */
 
 extern int			server_version_num;
@@ -333,6 +344,7 @@ RecoveryType get_recovery_type(PGconn *conn);
 int			 get_primary_node_id(PGconn *conn);
 bool		 can_use_pg_rewind(PGconn *conn, const char *data_directory, PQExpBufferData *reason);
 int 		 get_ready_archive_files(PGconn *conn, const char *data_directory);
+bool		 identify_system(PGconn *replconn, t_system_identification *identification);
 
 /* extension functions */
 ExtensionStatus get_repmgr_extension_status(PGconn *conn);
diff --git a/repmgr-action-node.c b/repmgr-action-node.c
index 53ef7c59..fe4cdf83 100644
--- a/repmgr-action-node.c
+++ b/repmgr-action-node.c
@@ -96,6 +96,28 @@ do_node_status(void)
 
 	get_node_replication_stats(conn, &node_info);
 
+	/* get system information */
+	{
+		t_conninfo_param_list repl_conninfo;
+		PGconn *replication_conn;
+		t_system_identification sysid = T_SYSTEM_IDENTIFICATION_INITIALIZER;
+		initialize_conninfo_params(&repl_conninfo, false);
+
+		conn_to_param_list(conn, &repl_conninfo);
+
+		param_set(&repl_conninfo, "replication", "1");
+
+		param_set(&repl_conninfo, "user", node_info.repluser);
+
+
+		replication_conn = establish_db_connection_by_params(&repl_conninfo, false);
+		identify_system(replication_conn, &sysid);
+
+		printf("%s\n", sysid.systemid);
+		exit(0);
+
+	}
+
 	key_value_list_set(
 		&node_status,
 		"PostgreSQL version",
diff --git a/repmgr.h b/repmgr.h
index 9aa17356..3fa783c0 100644
--- a/repmgr.h
+++ b/repmgr.h
@@ -33,6 +33,7 @@
 #define REPLICATION_TYPE_BDR	  2
 
 #define UNKNOWN_SERVER_VERSION_NUM -1
+#define UNKNOWN_TIMELINE_ID -1
 
 #define NODE_NOT_FOUND		-1
 #define NO_UPSTREAM_NODE	-1