Hey, I'm new to Docker and Linux and currently working on my first project. I've managed to deploy everything I need on a VDS server, and the command I'm using works perfectly: `docker compose --project-directory ./folder-name/ up --abort-on-container-exit`. But when I try to set this up as a cron job, I run into issues with it saying "crontab: invalid option -'" since there's no such flag as --project-directory for crontab. What should I do to format my command correctly for crontab? I think I might need to escape some characters. Also, I realized I was trying to directly input my cron expression instead of editing it properly in crontab. Just to clarify, I'm looking to run this command once a day because I have a Python script in one container that interacts with a PostgreSQL database in another, and I want to manage their lifecycle efficiently.
5 Answers
To make it easier, try wrapping your command in `bash -c "yourcommandhere"` or use `sh -c`. It helps with special characters. But, honestly, this approach seems a bit odd for what you're trying to do.
If your goal is to keep your images updated, have you considered using something like Watchtower instead? It automates the process without needing cron.
You might find it easier to create a bash script that contains your command and then run that script via cron. It simplifies things a lot!
Sounds like a good plan!
Possible issues might be:
1) There could be multiple Docker versions on your system and it's running an unexpected one.
2) Your problems may not even relate to the --project-directory flag. Including the actual output from your command could help diagnose the problem better.
Could you share what your full crontab line looks like? Also, I'm curious why you needed a cron job for `docker compose up`?
I need to run the script once a day. The script collects data and uses the database, but I don't need the database running the whole time, so starting it with the script fits my needs.
I get that it might seem weird, but this setup works for me, and using cron is just a way to schedule the task.