Knative Service invocation should use status.url instead of Istio IP

[bbrowning]

Knative Services should be invoked via the Service's status.url property instead of setting a host header and directly trying to hit the Istio ingress gateway. Not all Knative installations use Istio. Not all of the ones that do expose Istio directly to the internet via a LoadBalancer IP. Nor do all the ones that use Istio use the same service name and namespace as the hardcoded assumptions in the serverless-components/knative-serving repo.

Some Knative installations are not properly configured and the status.url of the Knative Service doesn't actually work. But, for properly configured ones, assuming you can directly talk to Istio is not a valid assumption.

[billfine]

Thanks @bbrowning. We'll take a look. Also, would love to chat re where we you think we should go with this project. Interested?

[bbrowning]

The PRs I opened here and in the serverless-components/knative-serving repo allow the serverless CLI to deploy Knative Services to an OpenShift 4 cluster as a regular (ie not cluster admin) user.

[bbrowning]

@billfine I'm happy to chat any time - I'll reach out on the serverless-contrib Slack.