Changing public url in knative service definition - kubernetes

Question

i'm playing around with knative currently and bootstrapped a simple installation using gloo and glooctl. Everything worked fine out of the box. However, i just asked myself if there is a possibility to change the generated url, where the service is made available at.
I already changed the domain, but i want to know if i could select a domain name without containing the namespace, so helloworld-go.namespace.mydomain.com would become helloworld-go.mydomain.com.
The current YAML-definition looks like this:
apiVersion: serving.knative.dev/v1alpha1
kind: Service
metadata:
labels:
name: helloworld-go
namespace: default
spec:
template:
spec:
containers:
- image: gcr.io/knative-samples/helloworld-go
env:
- name: TARGET
value: Go Sample v1
Thank you for your help!

Answer 1

This is configurable via the ConfigMap named config-network in the namespace knative-serving. See the ConfigMap in the deployment resources:
apiVersion: v1
data:
_example: |
...
# domainTemplate specifies the golang text template string to use
# when constructing the Knative service's DNS name. The default
# value is "{{.Name}}.{{.Namespace}}.{{.Domain}}". And those three
# values (Name, Namespace, Domain) are the only variables defined.
#
# Changing this value might be necessary when the extra levels in
# the domain name generated is problematic for wildcard certificates
# that only support a single level of domain name added to the
# certificate's domain. In those cases you might consider using a value
# of "{{.Name}}-{{.Namespace}}.{{.Domain}}", or removing the Namespace
# entirely from the template. When choosing a new value be thoughtful
# of the potential for conflicts - for example, when users choose to use
# characters such as `-` in their service, or namespace, names.
# {{.Annotations}} can be used for any customization in the go template if needed.
# We strongly recommend keeping namespace part of the template to avoid domain name clashes
# Example '{{.Name}}-{{.Namespace}}.{{ index .Annotations "sub"}}.{{.Domain}}'
# and you have an annotation {"sub":"foo"}, then the generated template would be {Name}-{Namespace}.foo.{Domain}
domainTemplate: "{{.Name}}.{{.Namespace}}.{{.Domain}}"
...
kind: ConfigMap
metadata:
labels:
serving.knative.dev/release: "v0.8.0"
name: config-network
namespace: knative-serving
Therefore, your config-network should look like this:
apiVersion: v1
data:
domainTemplate: {{ '"{{.Name}}.{{.Domain}}"' }}
kind: ConfigMap
metadata:
name: config-network
namespace: knative-serving
You can also have a look and customize the config-domain to configure the domain name that is appended to your services.

Answer 2

Assuming you're running knative over an istio service mesh, there's an example of how to use an Istio Virtual Service to accomplish this at the service level in the knative docs.