Add the flask-framework extension

[weiiwang01]

Bring the flask-framework extension from the feature/12f branch into the main branch.

The flask-extension is a part of the 12-factor toolchain that assists users in creating a charm to manage their Flask application within the Juju ecosystem.

As we are still awaiting some changes in other libraries to be finalized, please review the current content. I will update the pull request once the changes in the other libraries have been merged.

[weiiwang01]

@lengau, here's another pull request that cherry-picks only the flask-framework into the main branch, as per @sergiusens's recommendation.

[lengau]

Thanks for this!

Looking back at the other PR, I wasn't clear in what I was asking for with reorganising the constants for the gunicorn extensions. Sorry about that!

I've made what should be a clearer example of the change I'm requesting.

[lengau]

I gather you added this because something was failing - can you let me know what was failing, as that's probably a sign of a bigger bug.

[weiiwang01]

Sorry, this is too distant in the past, and I can't remember the context behind this change, and workflow logs have all been lost. Judging by this line, it seems to be caused by the prime directory not existing when creating the action.yaml?

Let me remove this line and run the test to see if that can trigger an error.

[lengau]

Looks good, thanks!

It looks like you have a different version of black from what we're using in CI. Running tox -f format with a recent enough version of tox (3.8+, so you should be ok to install tox from apt all the way back to jammy) should be consistent.

[lengau]

@weiiwang01 I'm not sure why this PR is causing the tests to timeout on macos, but it seems like it's waiting for user input, I think when running the integration tests for the init command. Could you check the permissions on the files you added, especially the templates?

[weiiwang01]

@weiiwang01 I'm not sure why this PR is causing the tests to timeout on macos, but it seems like it's waiting for user input, I think when running the integration tests for the init command. Could you check the permissions on the files you added, especially the templates?

I check the init templates, and the file permissions should be consistent with the other templates. Let me temporarily change the test command to see if we can identify which test is blocking.

[weiiwang01]

@weiiwang01 I'm not sure why this PR is causing the tests to timeout on macos, but it seems like it's waiting for user input, I think when running the integration tests for the init command. Could you check the permissions on the files you added, especially the templates?

I check the init templates, and the file permissions should be consistent with the other templates. Let me temporarily change the test command to see if we can identify which test is blocking.

Okay, I understand the problem: the flask-framework init profile does not generate a tox.ini file (in that use case, the tox configuration should be located in the project root, not in the charm/ directory). So, the test_tox_success test ends up executing the tox environment in charmcraft, which causes an infinite loop. I have added a directive to skip the test_tox_success test if a tox.ini file is not generated.