Verifying Knative Serving for Cloud Native Runtimes

This topic tells you how to verify that Knative Serving was successfully installed for Cloud Native Runtimes, commonly known as CNR.

About Verifying Knative Serving

To verify that Knative Serving was successfully installed, create an example Knative service and test it.

The procedure below shows you how to create an example Knative service using the Cloud Native Runtimes sample app, hello-yeti. This sample is custom built for Cloud Native Runtimes and is stored in the VMware Harbor registry.

Note: If you do not have access to the Harbor registry, you can use the Hello World - Go sample app in the Knative documentation.

Prerequisites

Before you verify Knative Serving, you must have a namespace where you want to deploy Knative services. This namespace will be referred as ${WORKLOAD_NAMESPACE} in this tutorial. See step 1 of Verifying Your Installation for more information.

Test Knative Serving

To create an example Knative service and use it to test Knative Serving:

1. If you are verifying on Tanzu Mission Control or vSphere 7.0 with Tanzu, then create a role binding in the ${WORKLOAD_NAMESPACE} namespace. Run:

   kubectl apply -n "${WORKLOAD_NAMESPACE}" -f - << EOF
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: RoleBinding
   metadata:
     name: ${WORKLOAD_NAMESPACE}-psp
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: ClusterRole
     name: cnr-restricted
   subjects:
   - kind: Group
     name: system:serviceaccounts:${WORKLOAD_NAMESPACE}
   EOF
   

2. Deploy the sample app using the kn CLI. Run:

   kn service create hello-yeti -n ${WORKLOAD_NAMESPACE} \
     --image projects.registry.vmware.com/tanzu_serverless/hello-yeti@sha256:17d640edc48776cfc604a14fbabf1b4f88443acc580052eef3a753751ee31652 --env TARGET='hello-yeti'
   

   If you are verifying on Tanzu Mission Control or vSphere 7.0 with Tanzu, then add --user 1001 to the command above to run it as a non-root user.

3. Run one of the following commands to retrieve the external address for your ingress, depending on your IaaS:

   IaaS:	Tanzu Kubernetes Grid on AWS Tanzu Mission Control on AWS Amazon Elastic Kubernetes Service
   Run:	export EXTERNAL_ADDRESS=$(kubectl get service envoy -n tanzu-system-ingress -ojsonpath="{.status.loadBalancer.ingress[0].hostname}")

   IaaS:	vSphere 7.0 on Tanzu Tanzu Kubernetes Grid on vSphere/Azure/GCP Tanzu Kubernetes Grid Integrated Edition Tanzu Mission Control on vSphere Azure Kubernetes Service Google Kubernetes Engine
   Run:	export EXTERNAL_ADDRESS=$(kubectl get service envoy -n tanzu-system-ingress -ojsonpath="{.status.loadBalancer.ingress[0].ip}")

   IaaS:	Docker desktop Minikube
   Run:	export EXTERNAL_ADDRESS='localhost:8080' And set up port-forwarding in a separate terminal: kubectl -n tanzu-system-ingress port-forward svc/envoy 8080:80

4. Connect to the app. Check the URL for the knative service.

   Run:

   kn service list -n ${WORKLOAD_NAMESPACE}
   

   The result is something like this:

   NAME           URL                                                          LATEST               AGE   CONDITIONS   READY   REASON
   hello-yeti     https://hello-yeti.${WORKLOAD_NAMESPACE}.svc.cluster.local   hello-yeti-00001     6s    3 OK / 3     True
   

   Now, take the host name from the URL and set it in an env variable KSERVICE_HOSTNAME like so:

   export KSERVICE_HOSTNAME="hello-yeti.${WORKLOAD_NAMESPACE}.svc.cluster.local"
   

   Then, connect to the app:

   curl https://${KSERVICE_HOSTNAME} -k --resolve ${KSERVICE_HOSTNAME}:443:${EXTERNAL_ADDRESS}
   

   Note: If you have configured DNS locally via /etc/hosts or externally, the --resolve flag can be omitted, or you can use a web browser.

   On success, you see a reply from our mascot, Carl the Yeti.

Delete the Example Knative Service

After verifying your serving installation, delete the example Knative service and unset the environment variable:

1. Run:

   kn service delete hello-yeti -n ${WORKLOAD_NAMESPACE}
   unset EXTERNAL_ADDRESS
   unset KSERVICE_HOSTNAME
   

2. If you created port forwarding in step 3 above, then terminate that process.