add a mechanism where the ctdb daemon will run a usercontrolled script when the node...

[sahlberg/ctdb.git] / server / ctdb_monitor.c

diff --git a/server/ctdb_monitor.c b/server/ctdb_monitor.c
index 21f0382d6b5d9f086219e04d7aaf3c31d9129847..46d9c632293fcecdce1116c6393098ff926b8164 100644 (file)
--- a/server/ctdb_monitor.c
+++ b/server/ctdb_monitor.c
@@ -33,6 +33,74 @@ struct ctdb_monitor_state {
 static void ctdb_check_health(struct event_context *ev, struct timed_event *te, 
                              struct timeval t, void *private_data);
 
+/*
+  setup the notification script
+*/
+int ctdb_set_notification_script(struct ctdb_context *ctdb, const char *script)
+{
+       ctdb->notification_script = talloc_strdup(ctdb, script);
+       CTDB_NO_MEMORY(ctdb, ctdb->notification_script);
+       return 0;
+}
+
+static int ctdb_run_notification_script_child(struct ctdb_context *ctdb, const char *event)
+{
+       struct stat st;
+       int ret;
+       char *cmd;
+
+       if (stat(ctdb->notification_script, &st) != 0) {
+               DEBUG(DEBUG_ERR,("Could not stat notification script %s. Can not send notifications.\n", ctdb->notification_script));
+               return -1;
+       }
+       if (!(st.st_mode & S_IXUSR)) {
+               DEBUG(DEBUG_ERR,("Notification script %s is not executable.\n", ctdb->notification_script));
+               return -1;
+       }
+
+       cmd = talloc_asprintf(ctdb, "%s %s\n", ctdb->notification_script, event);
+       CTDB_NO_MEMORY(ctdb, cmd);
+
+       ret = system(cmd);
+       /* if the system() call was successful, translate ret into the
+          return code from the command
+       */
+       if (ret != -1) {
+               ret = WEXITSTATUS(ret);
+       }
+       if (ret != 0) {
+               DEBUG(DEBUG_ERR,("Notification script \"%s\" failed with error %d\n", cmd, ret));
+       }
+
+       return ret;
+}
+
+static void ctdb_run_notification_script(struct ctdb_context *ctdb, const char *event)
+{
+       pid_t child;
+
+       if (ctdb->notification_script == NULL) {
+               return;
+       }
+
+       child = fork();
+       if (child == (pid_t)-1) {
+               DEBUG(DEBUG_ERR,("Failed to fork() a notification child process\n"));
+               return;
+       }
+       if (child == 0) {
+               int ret;
+
+               ret = ctdb_run_notification_script_child(ctdb, event);
+               if (ret != 0) {
+                       DEBUG(DEBUG_ERR,(__location__ " Notification script failed\n"));
+               }
+               _exit(0);
+       }
+
+       return;
+}
+
 /*
   called when a health monitoring event script finishes
  */
@@ -55,10 +123,13 @@ static void ctdb_health_callback(struct ctdb_context *ctdb, int status, void *p)
                        node->flags |= NODE_FLAGS_DISABLED;
                }
 
+               ctdb_run_notification_script(ctdb, "unhealthy");
        } else if (status == 0 && (node->flags & NODE_FLAGS_UNHEALTHY)) {
                DEBUG(DEBUG_NOTICE,("monitor event OK - node re-enabled\n"));
                node->flags &= ~NODE_FLAGS_UNHEALTHY;
                ctdb->monitor->next_interval = 1;
+
+               ctdb_run_notification_script(ctdb, "healthy");
        }
 
        next_interval = ctdb->monitor->next_interval;