Knative on OCP 4.1 Test Run

Install OCP 4.1.2

This blog assumes that you went to try.openshift.com and created your OCP 4.1 IPI cluster. If you have not, you can go to try.openshift.com –> Get Started to set up an OCP 4.1 cluster.

Install Istio (Maistra 0.11)

Istio is required before installing Knative. However, Knative operator will install the minimum Istio components if Istio is not installed on the platform. For my test, I did install service mesh on OCP 4.1 using the community version. Here are my steps:

• Install service mesh operator

oc new-project istio-operator
oc new-project istio-system
oc project istio-operator
oc apply -f https://raw.githubusercontent.com/Maistra/istio-operator/maistra-0.11/deploy/maistra-operator.yaml

• Service Mesh operator is up and running

#to get the name of the operator pod
oc get pods
#view the logs of the pod
oc logs <name of the pod from above step>

#log shown as below
{"level":"info","ts":1562602857.4691303,"logger":"kubebuilder.controller","caller":"controller/controller.go:153","msg":"Starting workers","Controller":"servicemeshcontrolplane-controller","WorkerCount":1}

• Create custom resource as cr.yaml using the below content.

apiVersion: maistra.io/v1
kind: ServiceMeshControlPlane
metadata:
  name: basic-install
spec:
  # NOTE, if you remove all children from an element, you should remove the
  # element too.  An empty element is interpreted as null and will override all
  # default values (i.e. no values will be specified for that element, not even
  # the defaults baked into the chart values.yaml).
  istio:
    global:
      proxy:
        # constrain resources for use in smaller environments
        resources:
          requests:
            cpu: 100m
            memory: 128Mi
          limits:
            cpu: 500m
            memory: 128Mi

    gateways:
      istio-egressgateway:
        # disable autoscaling for use in smaller environments
        autoscaleEnabled: false
      istio-ingressgateway:
        # disable autoscaling for use in smaller environments
        autoscaleEnabled: false
        # set to true to enable IOR
        ior_enabled: true

    mixer:
      policy:
        # disable autoscaling for use in smaller environments
        autoscaleEnabled: false

      telemetry:
        # disable autoscaling for use in smaller environments
        autoscaleEnabled: false
        # constrain resources for use in smaller environments
        resources:
          requests:
            cpu: 100m
            memory: 1G
          limits:
            cpu: 500m
            memory: 4G

    pilot:
      # disable autoscaling for use in smaller environments
      autoscaleEnabled: false
      # increase random sampling rate for development/testing
      traceSampling: 100.0

    kiali:
      # change to false to disable kiali
      enabled: true

      # to use oauth, remove the following 'dashboard' section (note, oauth is broken on OCP 4.0 with kiali 0.16.2)
      # create a secret for accessing kiali dashboard with the following credentials
      dashboard:
        user: admin
        passphrase: admin

    tracing:
      # change to false to disable tracing (i.e. jaeger)
      enabled: true

• Install service mesh

oc project istio-system
oc create -f cr.yaml

#it will take a while to have all the pods up
watch 'oc get pods'

• When service mesh is available

Every 2.0s: oc get pod -n istio-system                                                                                              Mon Jul  8 16:39:46 2019

NAME                                      READY   STATUS    RESTARTS   AGE
elasticsearch-0                           1/1     Running   0          13m
grafana-86dc5978b8-k2dvl                  1/1     Running   0          9m15s
ior-6656b5cfdb-cjt7z                      1/1     Running   0          9m55s
istio-citadel-7678d4749b-bjqq8            1/1     Running   0          14m
istio-egressgateway-66d8b969b8-wmcfm	  1/1     Running   0          9m55s
istio-galley-7f57cd4c6c-6d2r8             1/1     Running   0          11m
istio-ingressgateway-7794d8d4fc-dd72g     1/1     Running   0          9m55s
istio-pilot-77d65868d4-68lzd              2/2     Running   0          10m
istio-policy-7486f4cb6c-fdw6q             2/2     Running   0          11m
istio-sidecar-injector-66d49c6865-clqzm   1/1     Running   0          9m39s
istio-telemetry-799557976b-9ljz4          2/2     Running   0          11m
jaeger-agent-b7bz8                        1/1     Running   0          13m
jaeger-agent-j4dnp                        1/1     Running   0          13m
jaeger-agent-xmwzz                        1/1     Running   0          13m
jaeger-collector-96756f879-n889z          1/1     Running   3          13m
jaeger-query-6f4456546c-mwjkk             1/1     Running   3          13m
kiali-c58c8476d-wzhj6                     1/1     Running   0          8m45s
prometheus-5cb5d7549b-lmjtk               1/1     Running   0          14m

Install Knative 0.6

• Install Knative serving operator
  • Click Catalog -> OperatorHub -> search for “knative” keyword
  • Click “Knative Serving Operator”
  • Click “Install”

• Install Knative eventing operator
  • Click Catalog -> OperatorHub -> search for “knative” keyword
  • Click “Knative Eventing Operator”
  • Click “Install”

• I also manually scale up my nodes to prepare for the tutorial deployment.
• Click Compute -> Machine Sets
• Click “3 dots” at the end of each machine set-> click Edit Count -> enter 2

• validate (Installed Operator under openshift-operators project)

Install Knative Client – kn

Knative client CLI (kn) can list, create, delete, and update Knative service.

• Download the kn binary from https://github.com/knative/client/blob/master/docs/README.md#service-management
• Add to your path
• My kn installation

$ which kn
/usr/local/bin/kn
$ kn version
Version:      v20190625-13ff277
Build Date:   2019-06-25 09:52:20
Git Revision: 13ff277
Dependencies:
- serving:    

 

Let’s Have Some Fun

• The tutorial material is from https://github.com/redhat-developer-demos/knative-tutorial

Knative serving via kn

I am using my already build an image that is out in docker hub for this example. Here are the steps to create a simple Knative service.

oc new-project knative-demo
oc adm policy add-scc-to-user anyuid -z default -n knative-demo
oc adm policy add-scc-to-user privileged -z default -n knative-demo
kn service create mysvc --image docker.io/piggyvenus/greeter:0.0.1

List Knative service

$ kn service list
NAME    DOMAIN                                                        GENERATION   AGE   CONDITIONS   READY   REASON
mysvc   mysvc.knative-demo.apps.cluster-6c33.sandbox661.opentlc.com   1            29s   3 OK / 3     True    

Execute the service

$ curl mysvc.knative-demo.apps.cluster-6c33.sandbox661.opentlc.com
Hi  greeter => '0bd7a995d27e' : 1

Knative serving via a YAML file

Create Knative service YAML can also do the trick. Example, as shown below.

apiVersion: serving.knative.dev/v1alpha1
kind: Service
metadata:
  name: greeter
spec:
  runLatest:
    configuration:
      revisionTemplate:
        spec:
          container:
            image: docker.io/piggyvenus/greeter:0.0.1
            livenessProbe:
              httpGet:
                path: /healthz
            readinessProbe:
              httpGet:
                path: /healthz

 

Create Knative service

oc apply -f service.yaml

Check out Knative service resources

oc get deployment
oc get pods
oc get services.serving.knative.dev
oc get configuration.serving.knative.dev
oc get routes.serving.knative.dev

Invoke Knative service

oc get routes.serving.knative.dev
curl mysvc.knative-demo.apps.cluster-6c33.sandbox661.opentlc.com

Please check out Knative tutorial! There are more examples of Knative. I hope you find this blog useful.