repmgr: parse --no-slot in pg_basebackup_options

From PostgreSQL 10 we'll need to know whether this is present when
performing sanity checks for available replication slots.

Add a sanity check for conflicting presence of -S/--slot while we're
at it so we can abort early.

repmgr.c

@@ -158,7 +158,7 @@ static void param_set(t_conninfo_param_list *param_list, const char *param, cons
 static char *param_get(t_conninfo_param_list *param_list, const char *param);
 static bool parse_conninfo_string(const char *conninfo_str, t_conninfo_param_list *param_list, char *errmsg, bool ignore_application_name);
 static void conn_to_param_list(PGconn *conn, t_conninfo_param_list *param_list);
-static void parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_options *backup_options, int server_version_num);
+static bool parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_options *backup_options, int server_version_num, ItemList *error_list);
 
 static void config_file_list_init(t_configfile_list *list, int max_size);
 static void config_file_list_add(t_configfile_list *list, const char *file, const char *filename, bool in_data_dir);
@@ -6985,7 +6985,7 @@ run_basebackup(const char *data_dir, int server_version_num)
 	 * Parse the pg_basebackup_options provided in repmgr.conf - we'll want
 	 * to check later whether certain options were set by the user
 	 */
-	parse_pg_basebackup_options(options.pg_basebackup_options, &backup_options, server_version_num);
+	parse_pg_basebackup_options(options.pg_basebackup_options, &backup_options, server_version_num, NULL);
 
 	/* Create pg_basebackup command line options */
 
@@ -7793,6 +7793,8 @@ check_upstream_config(PGconn *conn, int server_version_num, bool exit_on_error)
 	bool		config_ok = true;
 	char	   *wal_error_message = NULL;
 	t_basebackup_options  backup_options = T_BASEBACKUP_OPTIONS_INITIALIZER;
+	bool		backup_options_ok = true;
+	ItemList	backup_option_errors = { NULL, NULL };
 	bool		xlog_stream = true;
 
 	enum {
@@ -7818,7 +7820,24 @@ check_upstream_config(PGconn *conn, int server_version_num, bool exit_on_error)
 	 * this will influence some checks
 	 */
 
-	parse_pg_basebackup_options(options.pg_basebackup_options, &backup_options, server_version_num);
+	backup_options_ok = parse_pg_basebackup_options(
+		options.pg_basebackup_options,
+		&backup_options, server_version_num,
+		&backup_option_errors);
+
+	if (backup_options_ok == false)
+	{
+		if (exit_on_error == true)
+		{
+			log_err(_("error(s) encountered parsing 'pg_basebackup_options'\n"));
+			print_error_list(&backup_option_errors, LOG_ERR);
+			log_hint(_("'pg_basebackup_options' is: '%s'\n"), options.pg_basebackup_options);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		config_ok = false;
+	}
+
 	if (strlen(backup_options.xlog_method) && strcmp(backup_options.xlog_method, "stream") != 0)
 		xlog_stream = false;
 
@@ -8668,8 +8687,8 @@ conn_to_param_list(PGconn *conn, t_conninfo_param_list *param_list)
 }
 
 
-static void
+static bool
-parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_options *backup_options, int server_version_num)
+parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_options *backup_options, int server_version_num, ItemList *error_list)
 {
 	int   options_len = strlen(pg_basebackup_options) + 1;
 	char *options_string = pg_malloc(options_len);
@@ -8691,6 +8710,8 @@ parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_opti
 
 	struct option *long_options;
 
+	bool		backup_options_ok = true;
+
 	/* We're only interested in these options */
 	static struct option long_options_9[] =
 	{
@@ -8699,17 +8720,21 @@ parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_opti
 		{NULL, 0, NULL, 0}
 	};
 
-	/* From PostgreSQL 10, --xlog-method is renamed --wal-method */
+	/*
+	 * From PostgreSQL 10, --xlog-method is renamed --wal-method
+	 * and there's also --no-slot, which we'll want to consider.
+	 */
 	static struct option long_options_10[] =
 	{
 		{"slot", required_argument, NULL, 'S'},
 		{"wal-method", required_argument, NULL, 'X'},
+		{"no-slot", no_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
 	/* Don't attempt to tokenise an empty string */
 	if (!strlen(pg_basebackup_options))
-		return;
+		return backup_options_ok;
 
 	if (server_version_num >= 100000)
 		long_options = long_options_10;
@@ -8761,6 +8786,9 @@ parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_opti
 	/* Reset getopt's optind variable */
 	optind = 0;
 
+	/* Prevent getopt from emitting errors */
+	opterr = 0;
+
 	while ((c = getopt_long(argc_item, argv_array, "S:X:", long_options,
 							&optindex)) != -1)
 	{
@@ -8772,10 +8800,32 @@ parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_opti
 			case 'X':
 				strncpy(backup_options->xlog_method, optarg, MAXLEN);
 				break;
+			case 1:
+				backup_options->no_slot = true;
+				break;
+			case '?':
+				if (server_version_num >= 100000 && optopt == 1)
+				{
+					if (error_list != NULL)
+					{
+						item_list_append(error_list, "invalid use of --no-slot");
+					}
+					backup_options_ok = false;
+				}
+				break;
 		}
 	}
 
-	return;
+	if (backup_options->no_slot == true && backup_options->slot[0] != '\0')
+	{
+		if (error_list != NULL)
+		{
+			item_list_append(error_list, "--no-slot cannot be used with -S/--slot");
+		}
+		backup_options_ok = false;
+	}
+
+	return backup_options_ok;
 }
 
 static void

repmgr.h

@@ -193,9 +193,10 @@ typedef struct
 {
 	char		slot[MAXLEN];
 	char		xlog_method[MAXLEN];
+	bool		no_slot; /* from PostgreSQL 10 */
 } t_basebackup_options;
 
-#define T_BASEBACKUP_OPTIONS_INITIALIZER { "", "" }
+#define T_BASEBACKUP_OPTIONS_INITIALIZER { "", "", false }
 
 typedef struct
 {