Refactor version number detection

Use the reported `server_version_num` integer for version number detection and comparison. This makes it easier to set an arbitrary minimum supported version (rather than "9.0 or later") as well as future-proofing for 10.x and later.
2026-03-23 07:06:30 +00:00 · 2014-12-29 14:54:04 +09:00
parent 4c64d52afb
commit f94626bf7b
5 changed files with 123 additions and 126 deletions
--- a/dbutils.c
+++ b/dbutils.c
@@ -178,46 +178,24 @@ is_pgup(PGconn *conn, int timeout)


 /*
- * If postgreSQL version is 9 or superior returns the major version
- * if 8 or inferior returns an empty string
+ * Return the server version number for the connection provided
 */
-char *
-pg_version(PGconn *conn, char *major_version)
+int
+get_server_version_num(PGconn *conn)
 {
 	PGresult   *res;
-
-	int			major_version1;
-	char	   *major_version2;
-
 	res = PQexec(conn,
-				 "WITH pg_version(ver) AS "
-				 "(SELECT split_part(version(), ' ', 2)) "
-				 "SELECT split_part(ver, '.', 1), split_part(ver, '.', 2) "
-				 "FROM pg_version");
+				 "SELECT current_setting('server_version_num')");

 	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
-		log_err(_("Version check PQexec failed: %s"),
+		log_err(_("Unable to determine server verson number:\n%s"),
 				PQerrorMessage(conn));
 		PQclear(res);
-		return NULL;
+		return -1;
 	}

-	major_version1 = atoi(PQgetvalue(res, 0, 0));
-	major_version2 = PQgetvalue(res, 0, 1);
-
-	if (major_version1 >= 9)
-	{
-		/* form a major version string */
-		xsnprintf(major_version, MAXVERSIONSTR, "%d.%s", major_version1,
-				  major_version2);
-	}
-	else
-		strcpy(major_version, "");
-
-	PQclear(res);
-
-	return major_version;
+	return atoi(PQgetvalue(res, 0, 0));
 }


--- a/dbutils.h
+++ b/dbutils.h
@@ -30,7 +30,7 @@ PGconn *establish_db_connection_by_params(const char *keywords[],
 int			is_standby(PGconn *conn);
 int			is_witness(PGconn *conn, char *schema, char *cluster, int node_id);
 bool		is_pgup(PGconn *conn, int timeout);
-char	   *pg_version(PGconn *conn, char *major_version);
+int         get_server_version_num(PGconn *conn);
 int guc_set(PGconn *conn, const char *parameter, const char *op,
 		const char *value);
 int guc_set_typed(PGconn *conn, const char *parameter, const char *op,
--- a/repmgr.c
+++ b/repmgr.c
@@ -525,28 +525,30 @@ do_master_register(void)
 {
 	PGconn	   *conn;
 	PGresult   *res;
-	char		sqlquery[QUERY_STR_LEN],
-			   *ret_ver;
+	char		sqlquery[QUERY_STR_LEN];

 	bool		schema_exists = false;
 	char		schema_quoted[MAXLEN];
-	char		master_version[MAXVERSIONSTR];
+	int			master_version_num = 0;
 	int			ret;

 	conn = establish_db_connection(options.conninfo, true);

-	/* master should be v9 or better */
+	/* Verify that master is a supported server version */
 	log_info(_("%s connecting to master database\n"), progname);
-	ret_ver = pg_version(conn, master_version);
-	if (ret_ver == NULL || strcmp(master_version, "") == 0)
+	master_version_num = get_server_version_num(conn);
+	if(master_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
 		PQfinish(conn);
-		if (ret_ver != NULL)
-			log_err(_("%s needs master to be PostgreSQL 9.0 or better\n"),
-					progname);
-		return;
+		if (master_version_num > 0)
+			log_err(_("%s needs master to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
+		exit(ERR_BAD_CONFIG);
 	}

+
 	/* Check we are a master */
 	log_info(_("%s connected to master, checking its state\n"), progname);
 	ret = is_standby(conn);
@@ -678,27 +680,27 @@ do_standby_register(void)
 				ret;

 	PGresult   *res;
-	char		sqlquery[QUERY_STR_LEN],
-			   *ret_ver;
+	char		sqlquery[QUERY_STR_LEN];
 	char		schema_quoted[MAXLEN];

-	char		master_version[MAXVERSIONSTR];
-	char		standby_version[MAXVERSIONSTR];
+	int			master_version_num = 0;
+	int			standby_version_num = 0;

 	/* XXX: A lot of copied code from do_master_register! Refactor */

 	log_info(_("%s connecting to standby database\n"), progname);
 	conn = establish_db_connection(options.conninfo, true);

-	/* should be v9 or better */
-	log_info(_("%s connected to standby, checking its state\n"), progname);
-	ret_ver = pg_version(conn, standby_version);
-	if (ret_ver == NULL || strcmp(standby_version, "") == 0)
+	/* Verify that standby is a supported server version */
+	standby_version_num = get_server_version_num(conn);
+	if(standby_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
 		PQfinish(conn);
-		if (ret_ver != NULL)
-			log_err(_("%s needs standby to be PostgreSQL 9.0 or better\n"),
-					progname);
+		if (standby_version_num > 0)
+			log_err(_("%s needs standby to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		exit(ERR_BAD_CONFIG);
 	}

@@ -733,6 +735,7 @@ do_standby_register(void)
 	res = PQexec(conn, sqlquery);
 	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
+		/* XXX error message does not match query */
 		log_err(_("Can't get info about tablespaces: %s\n"),
 				PQerrorMessage(conn));
 		PQclear(res);
@@ -760,26 +763,29 @@ do_standby_register(void)
 		exit(ERR_BAD_CONFIG);
 	}

-	/* master should be v9 or better */
+	/* Verify that master is a supported server version */
 	log_info(_("%s connected to master, checking its state\n"), progname);
-	ret_ver = pg_version(master_conn, master_version);
-	if (ret_ver == NULL || strcmp(master_version, "") == 0)
+	master_version_num = get_server_version_num(conn);
+	if(master_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
+		if (master_version_num > 0)
+			log_err(_("%s needs master to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		PQfinish(conn);
 		PQfinish(master_conn);
-		if (ret_ver != NULL)
-			log_err(_("%s needs master to be PostgreSQL 9.0 or better\n"),
-					progname);
 		exit(ERR_BAD_CONFIG);
 	}

 	/* master and standby version should match */
-	if (strcmp(master_version, standby_version) != 0)
+	if ((master_version_num / 100) != (standby_version_num / 100))
 	{
 		PQfinish(conn);
 		PQfinish(master_conn);
-		log_err(_("%s needs versions of both master (%s) and standby (%s) to match.\n"),
-				progname, master_version, standby_version);
+		/* XXX format version numbers */
+		log_err(_("%s needs versions of both master (%i) and standby (%i) to match.\n"),
+				progname, master_version_num, standby_version_num);
 		exit(ERR_BAD_CONFIG);
 	}

@@ -835,8 +841,8 @@ do_standby_clone(void)
 {
 	PGconn	   *conn;
 	PGresult   *res;
-	char		sqlquery[QUERY_STR_LEN],
-			   *ret;
+	char		sqlquery[QUERY_STR_LEN];
+
 	const char *cluster_size;

 	int			r = 0,
@@ -867,7 +873,7 @@ do_standby_clone(void)
 	char	   *first_wal_segment = NULL;
 	const char *last_wal_segment = NULL;

-	char		master_version[MAXVERSIONSTR];
+	int			master_version_num = 0;

 	/*
 	 * if dest_dir has been provided, we copy everything in the same path if
@@ -892,15 +898,18 @@ do_standby_clone(void)
 	log_info(_("%s connecting to master database\n"), progname);
 	conn = establish_db_connection_by_params(keywords, values, true);

-	/* primary should be v9 or better */
+	/* Verify that master is a supported server version */
 	log_info(_("%s connected to master, checking its state\n"), progname);
-	ret = pg_version(conn, master_version);
-	if (ret == NULL || strcmp(master_version, "") == 0)
+
+	master_version_num = get_server_version_num(conn);
+	if(master_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
 		PQfinish(conn);
-		if (ret != NULL)
-			log_err(_("%s needs master to be PostgreSQL 9.0 or better\n"),
-					progname);
+		if (master_version_num > 0)
+			log_err(_("%s needs master to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		exit(ERR_BAD_CONFIG);
 	}

@@ -960,8 +969,7 @@ do_standby_clone(void)
 	/*
 	 * Check if the tablespace locations exists and that we can write to them.
 	 */
-	if (strcmp(master_version, "9.0") == 0 ||
-		strcmp(master_version, "9.1") == 0)
+	if (master_version_num < 90200)
 		sqlquery_snprintf(sqlquery,
 						  "SELECT spclocation "
 						  "  FROM pg_tablespace "
@@ -1207,8 +1215,7 @@ do_standby_clone(void)
 	 * test_mode but it does not hurt too much (except if a tablespace is
 	 * created during the test)
 	 */
-	if (strcmp(master_version, "9.0") == 0 ||
-		strcmp(master_version, "9.1") == 0)
+	if (master_version_num < 90200)
 		sqlquery_snprintf(sqlquery,
 						  "SELECT spclocation "
 						  "  FROM pg_tablespace "
@@ -1367,8 +1374,8 @@ do_standby_promote(void)
 {
 	PGconn	   *conn;
 	PGresult   *res;
-	char		sqlquery[QUERY_STR_LEN],
-			   *ret;
+	char		sqlquery[QUERY_STR_LEN];
+
 	char		script[MAXLEN];

 	PGconn	   *old_master_conn;
@@ -1380,21 +1387,24 @@ do_standby_promote(void)
 	char		recovery_file_path[MAXFILENAME];
 	char		recovery_done_path[MAXFILENAME];

-	char		standby_version[MAXVERSIONSTR];
+	int			standby_version_num = 0;

 	/* We need to connect to check configuration */
 	log_info(_("%s connecting to standby database\n"), progname);
 	conn = establish_db_connection(options.conninfo, true);

-	/* we need v9 or better */
+	/* Verify that standby is a supported server version */
 	log_info(_("%s connected to standby, checking its state\n"), progname);
-	ret = pg_version(conn, standby_version);
-	if (ret == NULL || strcmp(standby_version, "") == 0)
+
+	standby_version_num = get_server_version_num(conn);
+	if(standby_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
-		if (ret != NULL)
-			log_err(_("%s needs standby to be PostgreSQL 9.0 or better\n"),
-					progname);
 		PQfinish(conn);
+		if (standby_version_num > 0)
+			log_err(_("%s needs standby to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		exit(ERR_BAD_CONFIG);
 	}

@@ -1485,8 +1495,7 @@ do_standby_follow(void)
 {
 	PGconn	   *conn;
 	PGresult   *res;
-	char		sqlquery[QUERY_STR_LEN],
-			   *ret;
+	char		sqlquery[QUERY_STR_LEN];
 	char		script[MAXLEN];
 	char		master_conninfo[MAXLEN];
 	PGconn	   *master_conn;
@@ -1496,13 +1505,27 @@ do_standby_follow(void)
 				retval;
 	char		data_dir[MAXLEN];

-	char		master_version[MAXVERSIONSTR];
-	char		standby_version[MAXVERSIONSTR];
+	int			master_version_num = 0;
+	int			standby_version_num = 0;
+

 	/* We need to connect to check configuration */
 	log_info(_("%s connecting to standby database\n"), progname);
 	conn = establish_db_connection(options.conninfo, true);

+	/* Verify that standby is a supported server version */
+	standby_version_num = get_server_version_num(conn);
+	if(standby_version_num < MIN_SUPPORTED_VERSION_NUM)
+	{
+		PQfinish(conn);
+		if (standby_version_num > 0)
+			log_err(_("%s needs standby to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
+		exit(ERR_BAD_CONFIG);
+	}
+
 	/* Check we are in a standby node */
 	log_info(_("%s connected to standby, checking its state\n"), progname);
 	retval = is_standby(conn);
@@ -1515,17 +1538,6 @@ do_standby_follow(void)
 		exit(ERR_BAD_CONFIG);
 	}

-	/* should be v9 or better */
-	ret = pg_version(conn, standby_version);
-	if (ret == NULL || strcmp(standby_version, "") == 0)
-	{
-		if (ret != NULL)
-			log_err(_("%s needs standby to be PostgreSQL 9.0 or better\n"),
-					progname);
-		PQfinish(conn);
-		exit(ERR_BAD_CONFIG);
-	}
-
 	/*
 	 * we also need to check if there is any master in the cluster or wait for
 	 * one to appear if we have set the wait option
@@ -1563,26 +1575,29 @@ do_standby_follow(void)
 		exit(ERR_BAD_CONFIG);
 	}

-	/* should be v9 or better */
+	/* Verify that master is a supported server version */
 	log_info(_("%s connected to master, checking its state\n"), progname);
-	ret = pg_version(master_conn, master_version);
-	if (ret == NULL || strcmp(master_version, "") == 0)
+	master_version_num = get_server_version_num(conn);
+	if(master_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
-		if (ret != NULL)
-			log_err(_("%s needs master to be PostgreSQL 9.0 or better\n"),
-					progname);
+		if (master_version_num > 0)
+			log_err(_("%s needs master to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		PQfinish(conn);
 		PQfinish(master_conn);
 		exit(ERR_BAD_CONFIG);
 	}

 	/* master and standby version should match */
-	if (strcmp(master_version, standby_version) != 0)
+	if ((master_version_num / 100) != (standby_version_num / 100))
 	{
-		log_err(_("%s needs versions of both master (%s) and standby (%s) to match.\n"),
-				progname, master_version, standby_version);
 		PQfinish(conn);
 		PQfinish(master_conn);
+		/* XXX format version numbers */
+		log_err(_("%s needs versions of both master (%i) and standby (%i) to match.\n"),
+				progname, master_version_num, standby_version_num);
 		exit(ERR_BAD_CONFIG);
 	}

@@ -1639,8 +1654,7 @@ do_witness_create(void)
 	PGconn	   *masterconn;
 	PGconn	   *witnessconn;
 	PGresult   *res;
-	char		sqlquery[QUERY_STR_LEN],
-			   *ret;
+	char		sqlquery[QUERY_STR_LEN];

 	char		script[MAXLEN];
 	char		buf[MAXLEN];
@@ -1650,9 +1664,8 @@ do_witness_create(void)
 				retval;
 	int			i;

-	char		master_version[MAXVERSIONSTR];
-
 	char		master_hba_file[MAXLEN];
+	int			master_version_num = 0;

 	/* Connection parameters for master only */
 	keywords[0] = "host";
@@ -1668,14 +1681,16 @@ do_witness_create(void)
 		exit(ERR_DB_CON);
 	}

-	/* primary should be v9 or better */
-	ret = pg_version(masterconn, master_version);
-	if (ret == NULL || strcmp(master_version, "") == 0)
+	/* Verify that master is a supported server version */
+	master_version_num = get_server_version_num(masterconn);
+	if(master_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
-		if (ret != NULL)
-			log_err(_("%s needs master to be PostgreSQL 9.0 or better\n"),
-					progname);
 		PQfinish(masterconn);
+		if (master_version_num > 0)
+			log_err(_("%s needs master to be PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		exit(ERR_BAD_CONFIG);
 	}

--- a/repmgr.h
+++ b/repmgr.h
@@ -32,6 +32,9 @@
 #define STANDBY_MODE		1
 #define WITNESS_MODE		2

+#define MIN_SUPPORTED_VERSION		"9.1"
+#define MIN_SUPPORTED_VERSION_NUM	90100
+
 #include "config.h"
 #define MAXFILENAME		1024
 #define ERRBUFF_SIZE		512
@@ -46,6 +49,7 @@
 #define MANUAL_FAILOVER		0
 #define AUTOMATIC_FAILOVER	1

+
 /* Run time options type */
 typedef struct
 {
--- a/repmgrd.c
+++ b/repmgrd.c
@@ -174,9 +174,7 @@ main(int argc, char **argv)
 	bool		daemonize = false;
 	FILE	   *fd;

-	char		standby_version[MAXVERSIONSTR],
-			   *ret_ver;
-
+	int			server_version_num = 0;
 	progname = get_progname(argv[0]);

 	if (argc > 1)
@@ -280,14 +278,16 @@ main(int argc, char **argv)
 			 local_options.conninfo);
 	my_local_conn = establish_db_connection(local_options.conninfo, true);

-	/* should be v9 or better */
-	log_info(_("%s Connected to database, checking its state\n"), progname);
-	ret_ver = pg_version(my_local_conn, standby_version);
-	if (ret_ver == NULL || strcmp(standby_version, "") == 0)
+	/* Verify that server is a supported version */
+	log_info(_("%s connected to database, checking its state\n"), progname);
+	server_version_num = get_server_version_num(my_local_conn);
+	if(server_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
-		if (ret_ver != NULL)
-			log_err(_("%s needs standby to be PostgreSQL 9.0 or better\n"),
-					progname);
+		if (server_version_num > 0)
+			log_err(_("%s requires PostgreSQL %s or better\n"),
+					progname,
+					MIN_SUPPORTED_VERSION
+				);
 		terminate(ERR_BAD_CONFIG);
 	}