newsroom/docker/cron

🕒 Cron Job Container

This folder contains the Docker configuration to run scheduled Symfony commands via cron inside a separate container.

• Run Symfony console commands periodically using a cron schedule (e.g. every 6 hours)
• Decouple scheduled jobs from the main PHP/FPM container
• Easily manage and test cron execution in a Dockerized Symfony project

---

Build & Run

1. Build the cron image
   From the project root:

   docker-compose build cron
   

2. Start the cron container

   docker-compose up -d cron
   

---

Cron Schedule

The default cron schedule is set to run every 6 hours:

0 */6 * * * root /run_commands.sh >> /var/log/cron.log 2>&1

To customize the schedule, edit the crontab file and rebuild the container.

---

Testing & Debugging

Manually test the command runner

You can run the script manually to check behavior without waiting for the cron trigger:

docker-compose exec cron /run_commands.sh

Check the cron output log

docker-compose exec cron tail -f /var/log/cron.log

Shell into the cron container

docker-compose exec cron bash

Once inside, you can:

• Check crontab entries: crontab -l
• Manually trigger cron: cron or cron -f (in another session)

---

Customization

• Add/Remove Symfony Commands:
  Edit run_commands.sh to include the commands you want to run.

• Change Schedule:
  Edit crontab using standard cron syntax.

• Logging:
  Logs are sent to /var/log/cron.log inside the container.

---

Rebuilding After Changes

If you modify the crontab or run_commands.sh, make sure to rebuild:

docker-compose build cron
docker-compose up -d cron

---

Notes

• Symfony project source is mounted at /var/www/html via volume.
• Make sure your commands do not rely on services (like php-fpm) that are not running in this container.