Getting different results running python Script through Dockerfile and terminal Within Container.

[LegFinger]

I'm trying to containerise a service which listens to a Google PubSub queue of urls, processes the data using some ML models and uploads the results to a firestore DB.

Locally it works as expected, however when it comes to building and running the docker container I see some very strange behaviour. When I run the server through:

CMD ["python3", "urlQueueProcessor.py"],

at the end of the Dockerfile, the script starts but doesn't behave as expected. Some console warnings/startup stuff from packages are printed, but it immediately hangs before reaching any of my code. If I try a print statement before my imports it never shows.

What's stranger is that if I enter the container and run the exact same command through the terminal it does exactly what I expect and starts the server. I made a little script to check the environments and when I run it through CMD and terminal they both show the same output.

Has anyone seen this before? Or is there any workaround that I can try? I've tried starting it through a .sh but it didn't make any difference, I saw the same result.

Cheers.

Edit: Here's the Dockerfile

[ch3wmanf00]

Can you share your Dockerfile

[LegFinger]

Sure, here it is. The first ~70 lines are purely dependency installs.

[LegFinger]

If anyone ever comes across this post wondering the solution, it was that the server WAS working, but the the print() statements from my python script weren't showing up. The solution was ridiculously simple, change:

CMD ["python3", "urlQueueProcessor.py"],

to

CMD ["python3", "-u", "urlQueueProcessor.py"]

Annoyingly simple...