Problem

Having too long namespace or kservice name can lead to an error like:

$ host wathola-receiver-test-continuous-events-propagation-with-prober-zxmkp.apps.example.org 
host: 'wathola-receiver-test-continuous-events-propagation-with-prober-zxmkp.apps.example.org' is not a legal IDN name (domain label longer than 63 characters), use +noidnin

In this case my namespace is test-continuous-events-propagation-with-prober-zxmkp and knative service name is wathola-receiver.

Concatenated with hypen, they together have length of 69, but maximum is 63 characters.

Proposition

Knative Serving having a goal of being user friendly and simplifying K8s work, should somehow address this issue. Serving should prevent creating too long CNAMEs.

Maybe Serving after detecting that given service will be unreachable, can generate a shorter version of service address, and keep track of it in internal serving ConfigMap. In that case we will prevent creating too long domain names, keeping the whole mechnism under the hood.

Steps to reproduce

$ # Install Serverless and Serving

$ oc create namespace test-continuous-events-propagation-with-prober-zxmkp

$ oc project test-continuous-events-propagation-with-prober-zxmkp

$ kn service create wathola-receiver --image quay.io/openshift-knative/wathola-receiver:v0.17.2

$ curl "$(oc get ksvc wathola-receiver -o jsonpath='{.status.url}')"