How to use celery rdb while working with python, flask, docker and docker compose?

Question

I use python, flask, celery, docker and docker compose in my project and wanted to use celery rdb to debug my tasks. I could not connect to celery container using telnet from my local machine to docker container.

Answer 1

I could not find an easy way to do it. Finally I ended up with followings:

1. install telnet into celery container (add on following Dockerfile )

# install system dependencies
RUN apt-get update && apt-get install -y telnet

2. trigger celery task. you will see logs output like this: Remote Debugger:6900: Ready to connect: telnet 127.0.0.1 6900
3. go into the celery container in another terminal

docker compose exec my_celery bash

4. run telnet command

root@fc4dcaa378xy:/usr/src/app# telnet 0.0.0.0 6900
    Trying 0.0.0.0...
    Connected to 0.0.0.0.
    Escape character is '^]'.
    > /usr/src/app/api/tasks.py(55)my_task()
    -> scraper_res = myfunc(url, *args, **kwargs)
    (Pdb) pp locals()