Add option --check-master-config

Consolidate the configuration checks carried out when cloning
a standby, and enable them to be run separately to check the
required configuration without running STANDBY CLONE multiple times.

repmgr.c

@@ -63,6 +63,7 @@ static bool create_schema(PGconn *conn);
 static bool copy_configuration(PGconn *masterconn, PGconn *witnessconn);
 static void write_primary_conninfo(char *line);
 static int	check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *server_version_string);
+static bool check_master_config(PGconn *conn, bool exit_on_error);
 
 static void do_master_register(void);
 static void do_standby_register(void);
@@ -72,6 +73,7 @@ static void do_standby_follow(void);
 static void do_witness_create(void);
 static void do_cluster_show(void);
 static void do_cluster_cleanup(void);
+static void do_check_master_config(void);
 
 static void usage(void);
 static void help(const char *progname);
@@ -115,12 +117,14 @@ main(int argc, char **argv)
 		{"min-recovery-apply-delay", required_argument, NULL, 'r'},
 		{"verbose", no_argument, NULL, 'v'},
 		{"initdb-no-pwprompt", no_argument, NULL, 1},
+		{"check-master-config", no_argument, NULL, 2},
 		{NULL, 0, NULL, 0}
 	};
 
 	int			optindex;
 	int			c, targ;
 	int			action = NO_ACTION;
+	bool 		check_master_config = false;
 	char *ptr = NULL;
 
 	progname = get_progname(argv[0]);
@@ -218,12 +222,21 @@ main(int argc, char **argv)
 			case 1:
 				runtime_options.initdb_no_pwprompt = true;
 				break;
+			case 2:
+				check_master_config = true;
+				break;
 			default:
 				usage();
 				exit(ERR_BAD_CONFIG);
 		}
 	}
 
+	if(check_master_config == true)
+	{
+		do_check_master_config();
+		exit(SUCCESS);
+	}
+
 	/*
 	 * Now we need to obtain the action, this comes in one of these forms:
 	 * MASTER REGISTER | STANDBY {REGISTER | CLONE [node] | PROMOTE | FOLLOW
@@ -825,8 +838,7 @@ do_standby_clone(void)
 	int			r = 0,
 				retval = SUCCESS;
 
-	int			i,
+	int			i;
-				is_standby_retval;
 	bool		flag_success = false;
 	bool		test_mode = false;
 
@@ -875,61 +887,7 @@ do_standby_clone(void)
 	log_info(_("%s connected to master, checking its state\n"), progname);
 	master_version_num = check_server_version(conn, "master", true, NULL);
 
-	/* ZZZ check user is qualified to perform base backup  */
+	check_master_config(conn, true);
-	/* Check we are cloning a primary node */
-	is_standby_retval = is_standby(conn);
-	if (is_standby_retval)
-	{
-		log_err(_(is_standby_retval == 1 ? "The command should clone a primary node\n" :
-				  "Connection to node lost!\n"));
-
-		PQfinish(conn);
-		exit(ERR_BAD_CONFIG);
-	}
-
-	/* And check if it is well configured */
-	i = guc_set(conn, "wal_level", "=", "hot_standby");
-	if (i == 0 || i == -1)
-	{
-		PQfinish(conn);
-		if (i == 0)
-			log_err(_("%s needs parameter 'wal_level' to be set to 'hot_standby'\n"),
-					progname);
-		exit(ERR_BAD_CONFIG);
-	}
-
-
-	/* ZZZ change this */
-	i = guc_set_typed(conn, "wal_keep_segments", ">=",
-					  runtime_options.wal_keep_segments, "integer");
-	if (i == 0 || i == -1)
-	{
-		PQfinish(conn);
-		if (i == 0)
-			log_err(_("%s needs parameter 'wal_keep_segments' to be set to %s or greater (see the '-w' option or edit the postgresql.conf of the PostgreSQL master.)\n"),
-					progname, runtime_options.wal_keep_segments);
-		exit(ERR_BAD_CONFIG);
-	}
-
-	i = guc_set(conn, "archive_mode", "=", "on");
-	if (i == 0 || i == -1)
-	{
-		PQfinish(conn);
-		if (i == 0)
-			log_err(_("%s needs parameter 'archive_mode' to be set to 'on'\n"),
-					progname);
-		exit(ERR_BAD_CONFIG);
-	}
-
-	i = guc_set(conn, "hot_standby", "=", "on");
-	if (i == 0 || i == -1)
-	{
-		PQfinish(conn);
-		if (i == 0)
-			log_err(_("%s needs parameter 'hot_standby' to be set to 'on'\n"),
-					progname);
-		exit(ERR_BAD_CONFIG);
-	}
 
 	/*
 	 * Check if the tablespace locations exists and that we can write to them.
@@ -1653,6 +1611,7 @@ help(const char *progname)
 	printf(_("  -W, --wait                          wait for a master to appear\n"));
 	printf(_("  -r, --min-recovery-apply-delay=VALUE  enable recovery time delay, value has to be a valid time atom (e.g. 5min)\n"));
 	printf(_("  --initdb-no-pwprompt                don't require superuser password when running initdb\n"));
+	printf(_("  --check-master-config               report problems with master configuration\n"));
 	printf(_("\n%s performs some tasks like clone a node, promote it or making follow\n"), progname);
 	printf(_("another node and then exits.\n\n"));
 	printf(_("COMMANDS:\n"));
@@ -2312,3 +2271,127 @@ check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *
 
 	return server_version_num;
 }
+
+
+/*
+ * check_master_config()
+ *
+ * Perform sanity check on master configuration
+ */
+static bool
+check_master_config(PGconn *conn, bool exit_on_error)
+{
+	int			i,
+				is_standby_retval;
+	bool		config_ok = true;
+
+	/* ZZZ check user is qualified to perform base backup  */
+	/* Check we are cloning a primary node */
+	is_standby_retval = is_standby(conn);
+	if (is_standby_retval)
+	{
+		log_err(_(is_standby_retval == 1 ? "The command should clone a primary node\n" :
+				  "Connection to node lost!\n"));
+
+		if(exit_on_error == true)
+		{
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		config_ok = false;
+	}
+
+	/* And check if it is well configured */
+	i = guc_set(conn, "wal_level", "=", "hot_standby");
+	if (i == 0 || i == -1)
+	{
+		if (i == 0)
+			log_err(_("%s needs parameter 'wal_level' to be set to 'hot_standby'\n"),
+					progname);
+		if(exit_on_error == true)
+		{
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		config_ok = false;
+	}
+
+	/* ZZZ change this */
+	i = guc_set_typed(conn, "wal_keep_segments", ">=",
+					  runtime_options.wal_keep_segments, "integer");
+	if (i == 0 || i == -1)
+	{
+		if (i == 0)
+			log_err(_("%s needs parameter 'wal_keep_segments' to be set to %s or greater (see the '-w' option or edit the postgresql.conf of the PostgreSQL master.)\n"),
+					progname, runtime_options.wal_keep_segments);
+
+		if(exit_on_error == true)
+		{
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		config_ok = false;
+	}
+
+	i = guc_set(conn, "archive_mode", "=", "on");
+	if (i == 0 || i == -1)
+	{
+		if (i == 0)
+			log_err(_("%s needs parameter 'archive_mode' to be set to 'on'\n"),
+					progname);
+		if(exit_on_error == true)
+		{
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		config_ok = false;
+	}
+
+	i = guc_set(conn, "hot_standby", "=", "on");
+	if (i == 0 || i == -1)
+	{
+		if (i == 0)
+			log_err(_("%s needs parameter 'hot_standby' to be set to 'on'\n"),
+					progname);
+
+		if(exit_on_error == true)
+		{
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		config_ok = false;
+	}
+
+	return config_ok;
+}
+
+static void
+do_check_master_config(void)
+{
+	PGconn	   *conn;
+
+	/* Connection parameters for master only */
+	keywords[0] = "host";
+	values[0] = runtime_options.host;
+	keywords[1] = "port";
+	values[1] = runtime_options.masterport;
+	keywords[2] = "dbname";
+	values[2] = runtime_options.dbname;
+	printf("%s %s\n", 	values[0], values[1]);
+	/* We need to connect to check configuration and start a backup */
+	log_info(_("%s connecting to master database\n"), progname);
+	conn = establish_db_connection_by_params(keywords, values, true);
+
+	/* Verify that master is a supported server version */
+	log_info(_("%s connected to master, checking its state\n"), progname);
+	check_server_version(conn, "master", false, NULL);
+
+	check_master_config(conn, false);
+
+	PQfinish(conn);
+}