feat: add cron task that runs the minimal training pipeline nightly

[bhearsum]

Relates to https://bugzilla.mozilla.org/show_bug.cgi?id=1937882, where we're adding integration tests for the translations pipeline in mozilla-releng/fxci-config#210. These work by looking a decision task and rerunning the tasks it creates (and those upstream of it). Running the pipeline on a cron schedule allows us to have an easily findable, up to date, decision task to point the tests at.

[bhearsum]

It looks like the defaults updating is causing some issues (either with some test assumptions, or genuine issues); moving back into draft while I work that out.

[bhearsum]

It looks like the defaults updating is causing some issues (either with some test assumptions, or genuine issues); moving back into draft while I work that out.

This turns out not to be necessary, so I removed it! (The defaults end up getting set in the parameters:

translations/taskcluster/translations_taskgraph/parameters.py

Line 105 in 7d45b3a

parameters.setdefault("training_config", {})

.)

This is ready for review now, but it does have #962 cherry picked to it to ensure the correct kind name is used. This isn't landable until that merges and I rebase on top of it.

[bhearsum]

cbc9e4c is the only part that needs review here.

[jcristau]

Kind of wondering if the cron job shouldn't be using an action instead of decision-task. That'd be a bit more code but wouldn't require the special-casing in get_decision_parameters.

Also, does this really need to run daily (vs weekly for gecko's os-integration cron)?

[bhearsum]

Kind of wondering if the cron job shouldn't be using an action instead of decision-task. That'd be a bit more code but wouldn't require the special-casing in get_decision_parameters.

Hmm...I do recall looking at that, but I'm not sure why that didn't work out. Or I might be confusing that with the abandoned mozilla-releng/fxci-config#192. I'll have a second look at this though; I agree that's cleaner if it works out.

Also, does this really need to run daily (vs weekly for gecko's os-integration cron)?

I think daily is actually more appropriate for this, because all meaningful tasks will be cached 99% of the time. Daily lets us virtually eliminate the possibility that an image change will run against outdated versions of these tasks.

[jcristau]

r+ to make it clear my comment isn't meant to be blocking.

[bhearsum]

I gave trigger-action another try over here. It reminded me that, unless I'm missing something, it would require duplicating the configuration into .cron.yml or somewhere in fxci-config to have the schema check pass.