Author: Nick Santos
Use Knative Serving to iterate on services that scale to zero.
Installs the knative operators into your cluster.
Auto-configures knative to use any local dev registries.
Registers a knative Serving resource for development.
Auto-configures the resource with min availability=1,
so that it will always be available for live updates.
Also adds a dependency on the resource created by knative_install().
See the test directory for a simple example.
This extension configures knative for local development. There are a few different pieces.
Knative installs a lot of CRDs.
If you're creating a dev environment from scratch, you want to make sure all those CRDs and their operators are healthy before you install resources.
This extension helps keep those deps straight.
Knative tries to resolve your image to a tag.
Tilt likes this behavior! In fact, Tilt likes it so much that it does this at build-time (rather than at deploy-time). When you're using Knative with Tilt, this behavior is redundant.
The problem is that Knative's approach to resolving images does not work well with dev registries. This extension tries to determine if you're using a dev registry, and turns tag resolution off.
https://knative.dev/docs/serving/configuration/deployment/#skipping-tag-resolution
If you're using live_update, and knative scales your service to zero, Tilt
won't have a place to sync your files.
We set the minimum number of pods to 1, to ensure there's always a place to sync files.
https://knative.dev/docs/serving/autoscaling/scale-bounds/
Knative also provides a way to turn off scale-to-zero globally, but this extension does it per-resource.