Add configuration parameter 'event_notifications'

config.c

@@ -24,6 +24,7 @@
 #include "strutil.h"
 #include "repmgr.h"
 
+static void parse_event_notifications_list(t_configuration_options *options, const char *arg);
 static void tablespace_list_append(t_configuration_options *options, const char *arg);
 
 
@@ -220,6 +221,8 @@ parse_config(const char *config_file, t_configuration_options *options)
 			options->ignore_external_config_files = atoi(value);
 		else if (strcmp(name, "event_notification_command") == 0)
 			strncpy(options->event_notification_command, value, MAXLEN);
+		else if (strcmp(name, "event_notifications") == 0)
+			parse_event_notifications_list(options, value);
 		else if (strcmp(name, "tablespace_mapping") == 0)
 			tablespace_list_append(options, value);
 		else
@@ -648,3 +651,69 @@ tablespace_list_append(t_configuration_options *options, const char *arg)
 
 	options->tablespace_mapping.tail = cell;
 }
+
+/*
+ * parse_event_notifications_list()
+ *
+ *
+ */
+
+static void
+parse_event_notifications_list(t_configuration_options *options, const char *arg)
+{
+	const char *arg_ptr;
+	char	    event_type_buf[MAXLEN] = "";
+	char	   *dst_ptr = event_type_buf;
+
+
+	for (arg_ptr = arg; arg_ptr <= (arg + strlen(arg)); arg_ptr++)
+	{
+		/* ignore whitespace */
+		if(*arg_ptr == ' ' || *arg_ptr == '\t')
+		{
+			continue;
+		}
+
+		/*
+		 * comma (or end-of-string) should mark the end of an event type -
+		 * just as long as there was something preceding it
+		 */
+		if((*arg_ptr == ',' || *arg_ptr == '\0') && event_type_buf[0] != '\0')
+		{
+			EventNotificationListCell *cell;
+
+			cell = (EventNotificationListCell *) pg_malloc0(sizeof(EventNotificationListCell));
+
+			if(cell == NULL)
+			{
+				log_err(_("unable to allocate memory. Terminating.\n"));
+				exit(ERR_BAD_CONFIG);
+			}
+
+			strncpy(cell->event_type, event_type_buf, MAXLEN);
+
+			if (options->event_notifications.tail)
+			{
+				options->event_notifications.tail->next = cell;
+			}
+			else
+			{
+				options->event_notifications.head = cell;
+			}
+
+			options->event_notifications.tail = cell;
+
+			memset(event_type_buf, 0, MAXLEN);
+			dst_ptr = event_type_buf;
+		}
+		/* ignore duplicated commas */
+		else if(*arg_ptr == ',')
+		{
+			continue;
+		}
+		else
+		{
+			*dst_ptr++ = *arg_ptr;
+		}
+	}
+}

config.h

@@ -25,6 +25,19 @@
 #include "strutil.h"
 
 
+typedef struct EventNotificationListCell
+{
+	struct EventNotificationListCell *next;
+	char event_type[MAXLEN];
+} EventNotificationListCell;
+
+
+typedef struct EventNotificationList
+{
+	EventNotificationListCell *head;
+	EventNotificationListCell *tail;
+} EventNotificationList;
+
 typedef struct TablespaceListCell
 {
 	struct TablespaceListCell *next;
@@ -63,12 +76,13 @@ typedef struct
 	int			monitor_interval_secs;
 	int			retry_promote_interval_secs;
 	int			use_replication_slots;
-	int         ignore_external_config_files;
+	int			ignore_external_config_files;
 	char		event_notification_command[MAXLEN];
+	EventNotificationList event_notifications;
 	TablespaceList tablespace_mapping;
 }	t_configuration_options;
 
-#define T_CONFIGURATION_OPTIONS_INITIALIZER { "", -1, NO_UPSTREAM_NODE, "", MANUAL_FAILOVER, -1, "", "", "", "", "", "", "", -1, -1, -1, "", "", "", "", 0, 0, 0, 0, "", {NULL, NULL} }
+#define T_CONFIGURATION_OPTIONS_INITIALIZER { "", -1, NO_UPSTREAM_NODE, "", MANUAL_FAILOVER, -1, "", "", "", "", "", "", "", -1, -1, -1, "", "", "", "", 0, 0, 0, 0, "", { NULL, NULL }, {NULL, NULL} }
 
 
 bool		parse_config(const char *config_file, t_configuration_options *options);

dbutils.c

@@ -1191,7 +1191,39 @@ create_event_record(PGconn *conn, t_configuration_options *options, int node_id,
 		const char *src_ptr;
 		char	   *dst_ptr;
 		char	   *end_ptr;
-		int r;
+		int	   	    r;
+
+		/*
+		 * If configuration option 'event_notifications' was provided,
+		 * check if this event is one of the ones listed; if not listed,
+		 * don't execute the notification script.
+		 *
+		 * (If 'event_notifications' was not provided, we assume the script
+		 * should be executed for all events).
+		 */
+		if(options->event_notifications.head != NULL)
+		{
+			EventNotificationListCell *cell;
+			bool notify_ok = false;
+
+			for (cell = options->event_notifications.head; cell; cell = cell->next)
+			{
+				if(strcmp(event, cell->event_type) == 0)
+				{
+					notify_ok = true;
+					break;
+				}
+			}
+
+			/*
+			 * Event type not found in the 'event_notifications' list - return early
+			 */
+			if(notify_ok == false)
+			{
+				log_debug(_("Not executing notification script for event type '%s'\n"), event);
+				return success;
+			}
+		}
 
 		dst_ptr = parsed_command;
 		end_ptr = parsed_command + MAXPGPATH - 1;