Merge "Support timeout for stats capture cron job"

config.yaml

@@ -83,6 +83,14 @@ options:
     description: |
       Cron schedule used to generate rabbitmq stats. To disable,
       either unset this config option or set it to an empty string ('').
+  cron-timeout:
+    type: int
+    default: 300
+    description: |
+      Run a command with a time limit specified in seconds in cron.
+      This timeout will govern to the rabbitmq stats capture, and that once
+      the timeout is reached a SIGINT is sent to the program, if it doesn't
+      exits before 10 seconds a SIGKILL is sent.
   queue_thresholds:
     type: string
     default: "[['\\*', '\\*', 100, 200]]"

hooks/rabbitmq_server_relations.py

@@ -109,6 +109,8 @@ STATS_CRONFILE = '/etc/cron.d/rabbitmq-stats'
 STATS_DATAFILE = os.path.join(RABBIT_DIR, 'data',
                               '{}_queue_stats.dat'
                               ''.format(rabbit.get_unit_hostname()))
+CRONJOB_CMD = ("{schedule} root timeout -k 10s -s SIGINT {timeout} "
+               "{command} 2>&1 | logger -p local0.notice\n")
 INITIAL_CLIENT_UPDATE_KEY = 'initial_client_update_done'
 
 
@@ -590,7 +592,9 @@ def update_nrpe_checks():
               os.path.join(NAGIOS_PLUGINS, 'check_rabbitmq_queues.py'))
     if config('stats_cron_schedule'):
         script = os.path.join(SCRIPTS_DIR, 'collect_rabbitmq_stats.sh')
-        cronjob = "{} root {}\n".format(config('stats_cron_schedule'), script)
+        cronjob = CRONJOB_CMD.format(schedule=config('stats_cron_schedule'),
+                                     timeout=config('cron-timeout'),
+                                     command=script)
         rsync(os.path.join(charm_dir(), 'scripts',
                            'collect_rabbitmq_stats.sh'), script)
         write_file(STATS_CRONFILE, cronjob)