Update tutorial-containerize-simple-web-app-for-app-service.md

[romusters]

The startup-file flag was not set when creating the web app resulting in the web app not working. The web app would simply remain stuck at 'loading' in the browser. Fortunately the startup.sh was given, but simply not used.

[prmerger-automator]

@romusters : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit d0352a4:

✅ Validation status: passed

File	Status	Preview URL	Details
articles/python/tutorial-containerize-simple-web-app-for-app-service.md	✅Succeeded

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[ShannonLeavitt]

@bobtabor-msft

Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team

[JimacoMS4]

Hi @romusters,

Thanks very much for pointing out this error in our documentation. You're right, FastAPI will hang without the startup command, which fires up uvicorn. However, Flask doesn't need a startup command. I'm going to create a PR that gives separate commands for Flask and FastAPI. To that end, I'm going to close this PR. Please check the article in the next day or two and you should see the update. Again, thanks very much for your help with this -- it's much appreciated!

-Jimaco

[JimacoMS4]

Hi @romusters When I tried this, I found that the FastAPI app worked without adding a startup command. You do have to wait a bit in the browser for the page to appear the first time. Can you share your exact experience with this? When you say it remained "stuck in loading" it leads me to think that maybe the browser window was closed before the app had a chance to fire up and load.

@bobtabor-msft FYI

[romusters]

Hi @romusters When I tried this, I found that the FastAPI app worked without adding a startup command. You do have to wait a bit in the browser for the page to appear the first time. Can you share your exact experience with this? When you say it remained "stuck in loading" it leads me to think that maybe the browser window was closed before the app had a chance to fire up and load.

@bobtabor-msft FYI

Hmm, I noticed later that pulling the docker layers took a longer then I normally used to time. So perhaps I was just impatient indeed. Apologies for wasting your time.

[JimacoMS4]

Not a waste of time at all. Appreciate your engagement with our docs.