repmgrd: add parameter "failover_delay"

This parameter is not documented and intended for use during testing.
It should not be used in production.

configdata.c

@@ -895,6 +895,16 @@ struct ConfigFileSetting config_file_settings[] =
 		{},
 		{}
 	},
+	/* failover_delay */
+	{
+		"failover_delay",
+		CONFIG_INT,
+		{ .intptr = &config_file_options.failover_delay },
+		{ .intdefault = 0 },
+		{ .intminval = 1 },
+		{},
+		{}
+	},
 	{
 		"connection_check_query",
 		CONFIG_STRING,

configfile.h

@@ -240,6 +240,7 @@ typedef struct
 
 	/* undocumented test settings */
 	int			promote_delay;
+	int			failover_delay;
 	char		connection_check_query[MAXLEN];
 } t_configuration_options;
 

repmgrd-physical.c

@@ -4178,6 +4178,13 @@ do_election(NodeInfoList *sibling_nodes, int *new_primary_id)
 
 	int			nodes_with_primary_still_visible = 0;
 
+	if (config_file_options.failover_delay > 0)
+	{
+		log_debug("sleeping %i seconds (\"failover_delay\") before initiating failover",
+				  config_file_options.failover_delay);
+		sleep(config_file_options.failover_delay);
+	}
+
 	/* we're visible */
 	stats.visible_nodes = 1;
 	stats.shared_upstream_nodes = 0;