lib-master: Add master_service_init_stats_client()

This allows initializing the stats client after master_service_init() if
necessary.

src/lib-master/master-service-settings.c

@@ -583,20 +583,14 @@ int master_service_settings_read(struct master_service *service,
 		/* running standalone. we want to ignore plugin versions. */
 		service->version_string = NULL;
 	}
-	if ((service->flags & MASTER_SERVICE_FLAG_SEND_STATS) != 0 &&
-	    service->stats_client == NULL &&
-	    service->set->stats_writer_socket_path[0] != '\0') T_BEGIN {
-		const char *path = t_strdup_printf("%s/%s",
-			service->set->base_dir,
-			service->set->stats_writer_socket_path);
+	if ((service->flags & MASTER_SERVICE_FLAG_SEND_STATS) != 0) {
 		/* When running standalone (e.g. doveadm) try to connect to the
 		   stats socket, but don't log an error if it's not running.
 		   It may be intentional. */
 		bool silent_notfound_errors =
 			(service->flags & MASTER_SERVICE_FLAG_STANDALONE) != 0;
-		service->stats_client =
-			stats_client_init(path, silent_notfound_errors);
-	} T_END;
+		master_service_init_stats_client(service, silent_notfound_errors);
+	}
 
 	if (service->set->shutdown_clients)
 		master_service_set_die_with_master(master_service, TRUE);

src/lib-master/master-service.c

@@ -451,6 +451,19 @@ void master_service_init_log(struct master_service *service,
 		service->log_initialized = TRUE;
 }
 
+void master_service_init_stats_client(struct master_service *service,
+				      bool silent_notfound_errors)
+{
+	if (service->stats_client == NULL &&
+	    service->set->stats_writer_socket_path[0] != '\0') T_BEGIN {
+		const char *path = t_strdup_printf("%s/%s",
+			service->set->base_dir,
+			service->set->stats_writer_socket_path);
+		service->stats_client =
+			stats_client_init(path, silent_notfound_errors);
+	} T_END;
+}
+
 void master_service_set_die_with_master(struct master_service *service,
 					bool set)
 {

src/lib-master/master-service.h

@@ -128,6 +128,12 @@ void master_service_env_clean(void);
    functions. The following calls change the log prefix. */
 void master_service_init_log(struct master_service *service,
 			     const char *prefix);
+/* Initialize stats client (if it's not already initialized). This is called
+   automatically if MASTER_SERVICE_FLAG_SEND_STATS is enabled. If
+   silent_notfound_errors is set, connect() errors aren't logged if they're
+   happening because the stats service isn't running. */
+void master_service_init_stats_client(struct master_service *service,
+				      bool silent_notfound_errors);
 
 /* If set, die immediately when connection to master is lost.
    Normally all existing clients are handled first. */