Change the CMD line to -

CMD ["gunicorn", "superlists.wsgi:application"]

And remove the EXPOSE line.

Thank you for your response, but I still get the "Application failed to respond" error after applying your changes.

Do you have a start command set elsewhere? service settings, Procfile, railway.json, etc. If so, remove it from anywhere that isn't that CMD line in your Dockerfile.

No, I don't have anything besides what I shared in the Dockerfile.

Maybe I use someone's Railway template for deployment with Django and add my code to it. Does such Railway template exist?

Yes, there is a django template, but that really should not be necessary.

Please attach your deployment logs -

https://bookmarklets.up.railway.app/log-downloader/

And attach your new Dockerfile.

Here are the build logs, the deploy logs and the Dockerfile. Thanks.

Going forward, please only ever use the bookmarklet to send your logs.

This is not needed and is bound to do more harm than good, please remove it, not to mention it's done incorrectly too.

# Read Railway environment variables
ENV DJANGO_SECRET_KEY=$DJANGO_SECRET_KEY
ENV DJANGO_ALLOWED_HOST=$DJANGO_ALLOWED_HOST

Tell me more about what your app does at first boot please, you may be running into the memory limits of the trial plan and causing your app to be killed.

Going forward, please only ever use the bookmarklet to send your logs.

Do you mean this?

https://bookmarklets.up.railway.app/log-downloader/

This is not needed and is bound to do more harm than good, please remove it, not to mention it's done incorrectly too.

I have this code in the settings.py of my Django project:

if "DJANGO_DEBUG_FALSE" in os.environ:
    DEBUG = False
    SECRET_KEY = os.environ["DJANGO_SECRET_KEY"]
    ALLOWED_HOSTS = [os.environ["DJANGO_ALLOWED_HOST"]]

I was running into other errors because settings.py could not find the variables I defined in "Variables" on the Railway.app UI. After deleting the lines in Dockerfile, I get the errors again, as you can see in the new logs attached.

Tell me more about what your app does at first boot please, you may be running into the memory limits of the trial plan and causing your app to be killed.

It's a very simple to-do list app that it's only half done as I'm reading the book Test-Driven Development with Python (https://www.obeythetestinggoat.com/). It shouldn't use much memory.

Looks like "python manage.py collectstatic" does need those variables, my bad I had not released something that collects static files would need those variables, and in that case, you'll need to add them back, but correctly -

# Read Railway environment variables
ARG DJANGO_SECRET_KEY
ARG DJANGO_ALLOWED_HOST

As for my idea of being out of memory -

[2024-04-22 02:50:51 +0000] [8] [INFO] Booting worker with pid: 8
[2024-04-22 03:06:49 +0000] [7] [INFO] Handling signal: term

Those events are not super close, So this seems more like the term signal that gets sent to the old deployment when a new deployment goes out. If so, nothing out of the ordinary there.

Can you make those ARG changes to your Dockerfile and then attach your latest deployment logs?

This fixed it! Thank you so much.

Awesome, it indeed did more harm how you had those environment variables.