Copied from #7991:

If you look at https://certbot.eff.org/docs/api/certbot.compat.filesystem.html, you'll notice many formatting errors which should be fixed.

That's the bare minimum which I think should be done, but I think we should also see what we can do to avoid these problems from happening in the future. Is there a way we could build the docs in CI and check for these problems?

The #1718 modified how static files are handled to prevent directory traversal. On that PR, some unit test were added to echo_test.go, but those test were not implemented for the Static Middleware (static_test.go)
The idea of this issue is to implement the missing test on the Static Middleware in relation to TestEchoStatic tests.

Is your feature request related to a problem? Please describe.
At cert-manager 1.0, there is ServiceMonitor to scrape certs metrics, but there is no alert(s) on certs renew failures to cluster operator.

Describe the solution you'd like
PrometheusRule object with alerting rules about expiring certs. Plus, ability to extend/override default rules via helm values.

/kind feature