celery: Add scheduled task update_beacon_receiver_distance

Celery beat is used to call update_beacon_receiver_distance_all
every five minutes.
The time interval is configurable by adjusting the configuration file.

README.md

@@ -81,18 +81,25 @@ To schedule tasks like takeoff/landing-detection (`logbook.compute`),
 The following scripts run in the foreground and should be deamonized
 (eg. use [supervisord](http://supervisord.org/)).
 
-- start aprs client
+- Start the aprs client
 
   ```
   ./manage.py gateway.run
   ```
 
-- start task server (make sure redis is up and running)
+- Start a task server (make sure redis is up and running)
 
   ```
   celery -A ogn.collect worker -l info
   ```
 
+- Start the task scheduler (make sure a task server is up and running)
+
+  ```
+  celery -A ogn.collect beat -l info
+  ```
+
+
 To load a custom configuration, create a file `myconfig.py` (see [config/default.py](config/default.py))
 and set the environment variable `OGN_CONFIG_MODULE` accordingly.
 
@@ -138,7 +145,7 @@ available commands:
 Only the command `logbook.compute` requires a running task server (celery) at the moment.
 
 
-### Scheduled tasks
+### Available tasks
 - ogn.collect.database
   - `import_ddb` - Import registered devices from the ddb
   - `import_file` - Import registered devices from a local file

config/default.py

@@ -2,3 +2,15 @@ SQLALCHEMY_DATABASE_URI = 'sqlite:///beacons.db'
 
 BROKER_URL = 'redis://localhost:6379/0'
 CELERY_RESULT_BACKEND = 'redis://localhost:6379/0'
+
+
+from datetime import timedelta
+
+CELERYBEAT_SCHEDULE = {
+    'update-receiver-distance': {
+        'task': 'ogn.collect.heatmap.update_beacon_receiver_distance_all',
+        'schedule': timedelta(minutes=5),
+    },
+}
+
+CELERY_TIMEZONE = 'UTC'

ogn/gateway/manage.py

@@ -2,7 +2,6 @@ import logging
 
 from ogn.gateway.client import ognGateway
 from ogn.commands.dbutils import session
-from ogn.collect.heatmap import update_beacon_receiver_distance
 
 from manager import Manager
 
@@ -35,8 +34,6 @@ def run(aprs_user='anon-dev', logfile='main.log', loglevel='INFO'):
     gateway.connect()
 
     def process_beacon(beacon):
-        if isinstance(beacon, ReceiverBeacon):
-            update_beacon_receiver_distance(beacon.name)
         session.add(beacon)
         session.commit()