Merge branch '10-add-support-for-scheduled-runs' into 'master'

Resolve "Add suport for time-based schedule"

Closes #10

See merge request ix.ai/cioban!82

README.md

@@ -25,6 +25,7 @@ Cioban will try to update your services every 5 minutes by default. The followin
 | **Variable**                | **Default** | **Description**                                                                                         |
 |:----------------------------|:-----------:|:--------------------------------------------------------------------------------------------------------|
 | `SLEEP_TIME`                | `6h`        | Adjust the sleeping time. Accepted are numbers ending in one of `s`, `m`, `h`, `d`, `w`|
+| `SCHEDULE_TIME`             | -           | Cron-Style string for scheduled runs. This will **disable** `SLEEP_TIME` |
 | `BLACKLIST_SERVICES`        | -           | Space-separated list of service names to exclude from updates |
 | `FILTER_SERVICES`           | -           | Anything accepted by the filtering flag in `docker service ls`. Example: `label=ai.ix.auto-update=true` |
 | `TELEGRAM_TOKEN`            | -           | See the [Telegram documentation](https://core.telegram.org/bots#creating-a-new-bot) how to get a new token |
@@ -49,6 +50,10 @@ Additionally, these environment variables are [supported](https://docker-py.read
 | `DOCKER_CERT_PATH`   | A path to a directory containing TLS certificates to use when connecting to the Docker host. (**Note**: this path needs to be present inside the `registry.gitlab.com/ix.ai/cioban` image) |
 
 
+## Cron-Style Scheduling
+
+`cioban` is using [cronsim](https://github.com/cuu508/cronsim) for parsing the `SCHEDULE_TIME`. For accepted values, please consult the [cronsim](https://github.com/cuu508/cronsim) documentation.
+
 ## Webhooks
 
 Starting with version `0.12.0`, `registry.gitlab.com/ix.ai/cioban` supports simple webhooks for each service, that are configured in the service labels.

cioban/__main__.py

@@ -20,7 +20,7 @@
 
 c = cioban.Cioban(**options)
 
-startup_message = (f"Starting **{__package__} {version}**. Exposing metrics on port {c.get_port()}")
+startup_message = f"Starting **{__package__} {version}**. Exposing metrics on port {c.get_port()}"
 log.warning(startup_message)
 c.notify(title="Startup", message=startup_message)
 

cioban/cioban.py

@@ -3,10 +3,12 @@
 """ A docker swarm service for automatically updating your services to the latest image tag push. """
 
 import logging
+from datetime import datetime
 import requests
 import pause
 import docker
 from prometheus_client import start_http_server
+from cronsim import CronSim, CronSimError
 from .lib import constants
 from .lib import prometheus
 from .lib import notifiers
@@ -21,6 +23,7 @@ class Cioban():
         'filter_services': {},
         'blacklist_services': {},
         'sleep_time': '6h',
+        'schedule_time': False,
         'prometheus_port': 9308,
         'notifiers': [],
         'notify_include_image': False,
@@ -37,26 +40,37 @@ def __init__(self, **kwargs):
             else:
                 log.debug(f'{k} not found in settings. Ignoring.')
         prometheus.PROM_INFO.info({'version': f'{constants.VERSION}-{constants.BUILD}'})
+
+        # Test schedule_time
+        if self.settings['schedule_time']:
+            log.debug('Disabling SLEEP_TIME because SCHEDULE_TIME is set.')
+            try:
+                CronSim(self.settings['schedule_time'], datetime.now())
+            except (CronSimError) as e:
+                raise CronSimError(f"{self.settings['schedule_time']} not understood. The error: {e}") from CronSimError
+
         relation = {
             's': 'seconds',
             'm': 'minutes',
             'h': 'hours',
             'd': 'days',
             'w': 'weeks',
         }
-        if any(s.isalpha() for s in self.settings['sleep_time']):
+
+        try:
+            self.sleep = int(self.settings['sleep_time'])
+            self.sleep_type = 'minutes'
+        except ValueError as exc:
             try:
                 self.sleep = int(self.settings['sleep_time'][:-1])
-            except ValueError:
-                raise ValueError(f"{self.settings['sleep_time']} not understood") from ValueError
+            except ValueError as e:
+                raise ValueError(f"{self.settings['sleep_time']} not understood. The error: {e}") from e
 
             if self.settings['sleep_time'][-1] in relation:
                 self.sleep_type = relation[self.settings['sleep_time'][-1]]
             else:
-                raise ValueError(f"{self.settings['sleep_time']} not understood")
-        else:
-            self.sleep = int(self.settings['sleep_time'])
-            self.sleep_type = 'minutes'
+                raise ValueError(f"{self.settings['sleep_time']} not understood") from exc
+
         self.register_notifiers(**kwargs)
 
         log.debug('Cioban initialized')
@@ -83,13 +97,20 @@ def run(self):
         start_http_server(self.settings['prometheus_port'])  # starts the prometheus metrics server
         log.info(f"Listening on port {self.settings['prometheus_port']}")
         while True:
-            prometheus.PROM_STATE_ENUM.state('running')
-            log.info('Starting update run')
-            self._run()
+            self.__set_timer()
             log.info(f'Sleeping for {self.sleep} {self.sleep_type}')
             prometheus.PROM_STATE_ENUM.state('sleeping')
             wait = getattr(pause, self.sleep_type)
             wait(self.sleep)
+            prometheus.PROM_STATE_ENUM.state('running')
+            log.info('Starting update run')
+            self._run()
+
+    def __set_timer(self):
+        self.sleep_type = 'seconds'
+        cron_timer = CronSim(self.settings['schedule_time'], datetime.now())
+        self.sleep = (next(cron_timer) - datetime.now()).seconds + 1
+        log.debug(f"Based on the cron schedule '{self.settings['schedule_time']}', next run is in {self.sleep}s")
 
     def __get_updated_image(self, image, image_sha):
         """ checks if an image has an update """

cioban/lib/helpers.py

@@ -28,6 +28,7 @@ def gather_environ(keys=None) -> dict:
             'notify_include_image': 'boolean',
             'notify_include_new_image': 'boolean',
             'notify_include_old_image': 'boolean',
+            'schedule_time': 'string',
             'sleep_time': 'string',
             'prometheus_port': 'int',
         }

cioban/requirements.txt

@@ -1,5 +1,7 @@
-prometheus_client==0.15.0
+prometheus_client==0.16.0
 docker==6.0.1
 pause==0.3
 pygelf==0.4.2
 ix-notifiers==0.0.259196408
+cronsim==2.3
+