fix: update cert secret if exists

[busser]

Fixes #378.

[hashicorp-cla]

All committers have signed the CLA.

[busser]

@tvoran no rush, but if you have time to take a look that would be great 🙂

[tvoran]

Thanks! This looks pretty good, just a thought about using the informer cache for the get.

[tvoran]

Looks like we'll also need to update the tests, since make test crashes in TestGenSource_leader(). I bet the secret informer will need to be setup in that test, similar to TestGenSource_follower().

It would also be great to add another test that starts with an empty secret with labels and annotations, runs the cert generation, then checks that the updated secret's labels and annotations are intact. Maybe another variant of TestGenSource_leader()?

[busser]

TestGenSource_leader() now fixed. Like you said, it just needed the informer to be setup.

I added a TestGenSource_leader_expiry(), which combines logic from TestGenSource_leader() and TestGenSource_expiry() to confirm that the secret retains its metadata when it is updated with a new bundle.

[tvoran]

Thanks for adding the tests!

[kenske]

Great work, thanks! Any idea when this will get released?

[tvoran]

@kenske Sometime later this month is the best estimate I can give right now.