Wednesday, May 25, 2022

[SOLVED] What is the best approach for adding cron jobs (scheduled tasks) for a particular service in docker-compose

Issue

I'm using a docker-compose. I have a web and a worker service.

version: '3'
services:
  web:
    build: .
    environment:
      - "*"
    links:
      - redis
      - memcached
    ports:
      - "80:8001"
      - "443:8001"

  worker:
    build: .
    command: ["/bin/bash", "/home/django/start_celery.sh"]
    environment:
      - "*"
    links:
      - redis
      - memcached

  memcached:
    image: memcached
    ports:
      - "11211:11211"

  redis:
    image: redis
    ports:
      - "6379:6379"

I need to run crons (scheduled tasks) on worker service.

And I dont want to hardcode the crontab in Dockerfile as I'm using same dockerfile for both the services.

So what is the best approach for this?


Solution

You can try the following Opensource tool for scheduling crons in the docker-compose.

https://github.com/mcuadros/ofelia

eg:

 [job-service-run "service-executed-on-new-container"]
 schedule = 0,20,40 * * * *
 image = ubuntu
 network = swarm_network
 command =  touch /tmp/example

In case you are planning to utilize the image in any of the cloud platforms.

For Eg.

AWS: You can also have a look at ECS scheduler

https://docs.aws.amazon.com/AmazonECS/latest/developerguide/scheduled_tasks.html

GCP: Kubernetes Engine CronScheduler

https://cloud.google.com/kubernetes-engine/docs/how-to/cronjobs



Answered By - Omkar Kulkarni
Answer Checked By - Pedro (WPSolving Volunteer)
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