Fix loading of periodic tasks and clean up extension loading.

[jezdez]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• New Query Runner (Data Source)
• New Alert Destination
• Other

Description

This does a few things:

• add tests for extension loading
• actually call the periodic tasks entry point callback instead of using the function to pass to Celery (regression!)
• refactor the extension and periodic task loading
• better handle assertions raised by extensions (e.g. when an extension tries to override an already registered view)
• attach exception traceback to error log during loading for improved debugging

[jezdez]

@arikfr Hey, just wanted to say that this is something we really need to ship in v8 since the periodic task loading mechanism was simply broken last time we touched the code. I forgot to not only load the entrypoints but also call the them to get the schedule parameters to be passed to Celery.

[arikfr]

💯 on adding tests. Can you see why they fail in the CI build?

[jezdez]

Hm, the tests pass locally, it's weird. Must be a difference in environment since it calls pip to actually install the dummy package. Let me see if I can figure out a different way to ship the dummy package.

[arikfr]

Did the local tests work inside a container?

[jezdez]

@arikfr Oh yeah, totally. I've been running them locally in the regular Docker dev environment.

I just pushed a change to use site.addsitedir instead of calling pip, let's see if this fixes it.

[jezdez]

Update: Yep, using site.addsitedir fixed it. I haven't a clue why calling pip didn't work on Circle.

[jezdez]

For the record, I created the egg-info directory (which is what is created in the site-packages directory when running pip install <packagename>) by running:

• make bash to create a shell inside the container
• cd tests/extensions
• pip install --user --editable redash-dummy/ to install the package in the user's "local" directory (~/.local) to work around the fact the containers runs as an unprivileged user
• pip uninstall --yes redash-dummy to simply remove it again

The egg-info directory is not cleaned up by pip, just the link in the ~/.local site-packages directory.

[arikfr]

How about adding the instructions on how to create the egg-info directory to a README file in the extension directory?

[arikfr]

👍