1. Enable the feature gate:

    oc patch featuregates/cluster --type=merge --patch='{"spec":{"featureSet":"CustomNoUpgrade","customNoUpgrade":{"enabled":["GatewayAPI"]}}}'

    oc get crds | grep -e gateway.networking.k8s.io -e maistra.io

2. Give the Ingress Operator cluster-admin permission:

    oc adm policy add-cluster-role-to-user cluster-admin -z ingress-operator -n openshift-ingress-operator

3. Get a pre-release build of OSSM 2.4 (see https://raw.githubusercontent.com/gcs278/istio-gateway-api-demo/master/install-ossm-daily-build.sh)
   sh install-ossm-daily-build.sh  
 
4. Patch the clusterserviceversion to use a development build of Envoy

    oc -n openshift-operators patch csv/servicemeshoperator.v2.4.0 --type=json --patch='[{"op":"replace","path":"/spec/install/spec/deployments/0/spec/template/metadata/annotations/olm.relatedImage.v2_4.proxyv2","value":"quay.io/maistra-dev/proxyv2-ubi8:2.4-latest"}]'

5. Create a gatewayclass:

oc create -f -<<'EOF'
apiVersion: gateway.networking.k8s.io/v1beta1
kind: GatewayClass
metadata:
  name: openshift-default
spec:
  controllerName: openshift.io/gateway-controller
EOF

6. Create a wildcard certificate and secret:

    base_domain="$(oc get dnses.config/cluster -o jsonpath='{.spec.baseDomain}')"
    gwapi_domain="gwapi.${base_domain}"
    mkdir /tmp/gwapi
    openssl req -x509 -newkey rsa:4096 -sha256 -days 365 -keyout /tmp/gwapi/ca.key -out /tmp/gwapi/ca.crt -nodes -subj '/C=US/ST=NC/L=Chocowinity/O=OS3/OU=Eng/CN=gwapi-ca' && openssl req -newkey rsa:4096 -nodes -sha256 -keyout /tmp/gwapi/wildcard.key -out /tmp/gwapi/wildcard.csr -subj "/C=US/ST=NC/L=Chocowinity/O=OS3/OU=Eng/CN=*.$gwapi_domain" && openssl x509 -req -days 365 -in /tmp/gwapi/wildcard.csr -signkey /tmp/gwapi/wildcard.key -CA /tmp/gwapi/ca.crt -CAcreateserial -CAkey /tmp/gwapi/ca.key -out /tmp/gwapi/wildcard.crt
    oc -n openshift-ingress create secret tls gwapi-wildcard --cert=/tmp/gwapi/wildcard.crt --key=/tmp/gwapi/wildcard.key

7. Create a gateway:

oc create -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1beta1
kind: Gateway
metadata:
  name: gateway
  namespace: openshift-ingress
spec:
  gatewayClassName: openshift-default
  listeners:
  - name: http
    hostname: "*.$gwapi_domain"
    port: 80
    protocol: HTTP
    allowedRoutes:
      namespaces:
        from: All
  - name: https
    hostname: "*.$gwapi_domain"
    port: 443
    protocol: HTTPS
    tls:
      mode: Terminate
      certificateRefs:
      - name: gwapi-wildcard
    allowedRoutes:
      namespaces:
        from: All
EOF

8. Create a demo application:

    oc new-project demo-app
    oc new-app -n demo-app --name foo-app https://github.com/openshiftdemos/cakephp-ingress-demo\#foo

9. Create an httproute:

oc apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: http
  namespace: demo-app
spec:
  parentRefs:
  - name: gateway
    namespace: openshift-ingress
  hostnames: ["test.$gwapi_domain"]
  rules:
  - backendRefs:
    - name: foo-app
      port: 8080
EOF

10. Curl the application:

    curl --cacert /tmp/gwapi/ca.crt "https://test.$gwapi_domain/"