Routing based on hostname with regex / wildcards and priorities / weights

[niklaskorz]

We are currently using Traefik for our staging and review environments.
Our setup looks like this:

• staging is running on example.com and review-([a-z0-9-]+).example.com and has a priority of 30
• the review environments are running on review-{env}.example.com and have a priority of 40

This way, we can have review environments that only spawn some microservices and fallback the staging services for services that aren't deployed in the environment.

For example, if a web frontend service is deployed at / in staging and in a review environment called test, but the api service at /api is only deployed in staging, accessing:

• review-test.example.com/ routes the request to the review environment web frontend
• review-test.example.com/api routes the request to the staging api service

We had a similar setup before using Ambassador which is also based on Envoy, suggesting that this workflow generally works with Envoy.
Can something like this be accomplished with Contour as well?

[youngnick]

@niklaskorz right now, we don't support any wildcard hostname matching at all for HTTPProxy (see #1228 for more background), but for Ingress and the new Gateway API support, we only support full-label wildcards, as in their spec.

We are planning on implementing single-label wildcards for HTTPProxy at some point, which would allow you to do this fallback-style config, I think. The path parts are easy to implement using HTTPProxy or Ingress already, it's just the hostname parts that are tricky.