celery pdb running inside docker container with changing listening port

Question

Looking for advice on how I can run celery pdb inside my docker container while port forwarding so i can access from the outside world.

I am following the guide at http://celery.readthedocs.org/en/latest/tutorials/debugging.html

The issue I am facing is that even when I tell the container.

-e CELERY_RDB_HOST='0.0.0.0' -e CELERY_RDB_PORT='6900' -p 6900:6900.

And get to the breakpoint in the app, the port that actually gets open is not what I asked for so my port forward no longer is valid.... Eg. the port 6902 gets opened instead, and no matter what I ask the port to be, it changes again to not what I asked for.

I know it chooses from a list of 100 ports that it deems 'available' but not sure how to get around this problem. Any advise would be welcome.

Thanks!

Answer 1

You can run your container by specifying a range of ports (see http://docs.docker.com/reference/run/#expose-incoming-ports):

docker run -d -e CELERY_RDB_HOST='0.0.0.0' -p 6900-7000:6900-7000 celery

After that, when you hit your breakpoint, you just need to telnet into it:

telnet localhost 6902