how to install knative and create service

knative official docs

https://knative.dev/docs/

 

Migrating a Cloud Run for Anthos service to Knative

https://cloud.google.com/anthos/run/docs/migrate/knative

 

# install knative cli

 

https://knative.dev/docs/client/install-kn/#install-the-knative-cli

 

brew install knative/client/kn

kn version

 

# install knative operator

 

check latest release

https://github.com/knative/operator/releases

 

kubectl apply -f https://github.com/knative/operator/releases/download/knative-v1.10.2/operator.yaml

# check
kubectl get deployment knative-operator

 

# output
secret "operator-webhook-certs" created
deployment.apps "operator-webhook" created
service "operator-webhook" created
customresourcedefinition.apiextensions.k8s.io "knativeeventings.operator.knative.dev" created
customresourcedefinition.apiextensions.k8s.io "knativeservings.operator.knative.dev" created
clusterrole.rbac.authorization.k8s.io "knative-serving-operator-aggregated" created
clusterrole.rbac.authorization.k8s.io "knative-serving-operator-aggregated-stable" created
clusterrole.rbac.authorization.k8s.io "knative-eventing-operator-aggregated" created
clusterrole.rbac.authorization.k8s.io "knative-eventing-operator-aggregated-stable" created
clusterrole.rbac.authorization.k8s.io "knative-serving-operator" created
clusterrole.rbac.authorization.k8s.io "knative-eventing-operator" created
serviceaccount "knative-operator" created
clusterrolebinding.rbac.authorization.k8s.io "knative-serving-operator" created
clusterrolebinding.rbac.authorization.k8s.io "knative-eventing-operator" created
role.rbac.authorization.k8s.io "knative-operator-webhook" created
clusterrole.rbac.authorization.k8s.io "knative-operator-webhook" created
serviceaccount "operator-webhook" created
rolebinding.rbac.authorization.k8s.io "operator-webhook" created
clusterrolebinding.rbac.authorization.k8s.io "operator-webhook" created
clusterrolebinding.rbac.authorization.k8s.io "knative-serving-operator-aggregated" created
clusterrolebinding.rbac.authorization.k8s.io "knative-serving-operator-aggregated-stable" created
clusterrolebinding.rbac.authorization.k8s.io "knative-eventing-operator-aggregated" created
clusterrolebinding.rbac.authorization.k8s.io "knative-eventing-operator-aggregated-stable" created
configmap "config-logging" created
configmap "config-observability" created
deployment.apps "knative-operator" created

 

# install istio

-> knative requires istio as networking layer. so istio installation is required.

 

## install istio with istio operator

 

https://istio.io/latest/docs/setup/install/operator/

 

cf. IstioOperator options

https://istio.io/latest/docs/reference/config/istio.operator.v1alpha1/

 

https://istio.io/v1.5/docs/reference/config/installation-options/

 

istioctl operator init
-> istio-operator related resources are created in the istio-operator namespace.
-> Istio is automatically deployed when an IstioOperator resource is created.
-> If the IstioOperator changes after the initial deployment of istio, the istio operator reflects the changes to istio in real time.

 

kubectl apply -f - <<EOF
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
metadata:
  namespace: istio-system
  name: istiocontrolplane
spec:
  profile: demo
  meshConfig:
    accessLogFile: /dev/stdout
  values:
    pilot:
      enabled: true
      autoscaleEnabled: true
      autoscaleMin: 1
      autoscaleMax: 5
      resources:
        requests:
          cpu: 500m
          memory: 2048Mi
        limits:
          cpu: 500m
          memory: 2048Mi
    gateways:
      istio-ingressgateway:
        autoscaleEnabled: true
        type: LoadBalancer
      istio-egressgateway:
        autoscaleEnabled: true
EOF

kubectl get IstioOperator -n istio-system

kubectl label namespace default istio-injection=enabled
kubectl get ns --show-labels

 

# install KnativeServing

-> All knative serving-related settings are applied through the KnativeServing resource.

-> The configmap of the knative-serving namespace is automatically modified (do not change it manually, just modify the KnativeServing resource).

-> KnativeServing resource automatically creates istio's gateway resource in the knative-serving namespace.

 

https://knative.dev/docs/serving/

 

https://knative.dev/docs/install/operator/configuring-serving-cr/

 

https://knative.dev/docs/serving/setting-up-custom-ingress-gateway/

 

https://knative.dev/docs/install/operator/configuring-with-operator/

 

list of configmap

https://github.com/knative/serving/tree/main/config/core/configmaps

 

vim knative-serving.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: knative-serving
---
apiVersion: operator.knative.dev/v1beta1
kind: KnativeServing
metadata:
  name: knative-serving
  namespace: knative-serving
spec:
  config:
    domain:
      svc.cluster.local: |
        selector:
          type: internal
      prod.127.0.0.1.nip.io: |
        selector:
          env: prod
      dev.127.0.0.1.nip.io: |
        selector:
          env: dev
      test.127.0.0.1.nip.io: ""
    autoscaler:
      min-scale: "1"
      max-scale: "10"


kubectl apply -f knative-serving.yaml

# check
kubectl get KnativeServing knative-serving -n knative-serving

# check component of KnativeServing
kubectl get deployment -n knative-serving

 

# output
NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
activator               1/1     1            1           113m
autoscaler              1/1     1            1           113m
autoscaler-hpa          1/1     1            1           113m
controller              1/1     1            1           113m
domain-mapping          1/1     1            1           113m
domainmapping-webhook   1/1     1            1           113m
net-istio-controller    1/1     1            1           110m
net-istio-webhook       1/1     1            1           110m
webhook                 1/1     1            1           113m

# check configmap of KnativeServing
kubectl get cm -n knative-serving

 

# deploy "helloworld" sample service

-> When creating a knative service, resources such as deployment and virtual service are automatically created.

 

Deploying a Knative Service

https://knative.dev/docs/getting-started/first-service/

 

Knative code samples

https://github.com/knative/docs/tree/main/code-samples/serving

 

vim hello.yaml

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: hello
spec:
  template:
    spec:
      containers:
        - image: ghcr.io/knative/helloworld-go:latest
          ports:
            - containerPort: 8080
          env:
            - name: TARGET
              value: "World"


kubectl apply -f hello.yaml

 

# check access domain
kubectl get route
-> kn route list

# output
NAME          URL                                             READY   REASON
hello         http://hello.default.test.127.0.0.1.nip.io      True

# check list of knative services
kubectl get ksvc
-> kn service list

# output
NAME          URL                                             LATESTCREATED       LATESTREADY         READY   REASON
hello         http://hello.default.test.127.0.0.1.nip.io      hello-00001         hello-00001         True

# check list of revisions
kubectl get rev
-> kn revision list

# output
NAME                CONFIG NAME   K8S SERVICE NAME   GENERATION   READY   REASON   ACTUAL REPLICAS   DESIRED REPLICAS
hello-00001         hello                            1            True             1                 1

 

# Create a sample service with a dev domain

-> If the key/value applied to the domain selector is set in metadata.labels of the Service resource, the domain is granted according to the rules.

 

vim hello-dev.yaml

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: hello-dev
  labels:
    env: dev
spec:
  template:
    spec:
      containers:
        - image: ghcr.io/knative/helloworld-go:latest
          ports:
            - containerPort: 8080
          env:
            - name: TARGET
              value: "World"

 

# check access domain
kubectl get route

# output
NAME          URL                                             READY   REASON
hello-dev     http://hello-dev.default.dev.127.0.0.1.nip.io   True

# check virtual service
kubectl get vs | grep hello-dev

# output
hello-dev-ingress     ["knative-serving/knative-ingress-gateway","knative-serving/knative-local-gateway"]   ["hello-dev.default","hello-dev.default.dev.127.0.0.1.nip.io","hello-dev.default.svc","hello-dev.default.svc.cluster.local"]   7m13s
hello-dev-mesh        ["mesh"]                                                                              ["hello-dev.default","hello-dev.default.svc","hello-dev.default.svc.cluster.local"]                                            7m13s

 

# Create a sample service with a local domain

vim hello-local.yaml

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: hello-local
  labels:
    type: internal
spec:
  template:
    spec:
      containers:
        - image: ghcr.io/knative/helloworld-go:latest
          ports:
            - containerPort: 8080
          env:
            - name: TARGET
              value: "World"

 

# check access domain
kubectl get route

# output
NAME          URL                                             READY   REASON
hello-local   http://hello-local.default.svc.cluster.local    True

# check virtual service
kubectl get vs | grep hello-local

# output
hello-local-ingress   ["knative-serving/knative-local-gateway"]                                             ["hello-local.default","hello-local.default.svc","hello-local.default.svc.cluster.local"]                                      6m44s
hello-local-mesh      ["mesh"]                                                                              ["hello-local.default","hello-local.default.svc","hello-local.default.svc.cluster.local"]                                      6m44s

 

# deletion

 

## delete knative resources

kubectl delete -f hello.yaml
kubectl delete -f hello-dev.yaml
kubectl delete -f hello-local.yaml

kubectl delete KnativeServing knative-serving -n knative-serving

 

## delete istio

kubectl delete IstioOperator -n istio-system istiocontrolplane
istioctl uninstall -y --purge
kubectl delete ns istio-system istio-operator --grace-period=0 --force

 

## delete knative operator

kubectl delete -f https://github.com/knative/operator/releases/download/knative-v1.10.2/operator.yaml

 

## delete knative crd

kubectl api-resources -o name | grep knative | xargs kubectl delete crd