Deploy a Knative application

See the Knative Service (opens new window) documentation to get an overview about deploying your applications with Knative.

Deploy via kn CLI

The easiest way to deploy a Knative application (called service in Knative) is to directly deploy it with the kn CLI:

$ kn --namespace demo \
  service create hello-world \
  --image gcr.io/knative-samples/helloworld-go \
  --port 8080 \
  --env TARGET=World

Deploy via YAML

Instead of using kn you can of course also just as well use YAML files and deploy them with kubectl:

knative-hello-world.yaml

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

$ kubectl -n demo apply -f knative-hello-world.yaml

The result would be the same as with kn.

List applications

$ kn -n demo service list

NAME          URL                                                  LATEST              AGE   CONDITIONS   READY   REASON
hello-world   https://hello-world.demo.kube-plus.cloud   hello-world-00001   44m   3 OK / 3     True

Inspect an application

$ kn -n demo service describe hello-world

Name:       hello-world
Namespace:  demo
Age:        2h
URL:        https://hello-world.demo.kube-plus.cloud

Revisions:
  100%  @latest (hello-world-00001) [1] (2h)
        Image:     gcr.io/knative-samples/helloworld-go (pinned to 5ea96b)
        Replicas:  0/0

Conditions:
  OK TYPE                   AGE REASON
  ++ Ready                   2h
  ++ ConfigurationsReady     2h
  ++ RoutesReady             2h

Update an application

$ kn -n demo service hello-world \
  --scale-min 5 --scale-max 10 \
  --request cpu=500m \
  --limit memory=1024Mi --limit cpu=1000m

Be sure to check out the full documentation (opens new window) on kn service update.

Autoscaling

Check out this documentation on how Knative Autoscaling (opens new window) for applications works.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: my-autoscaling-app
  namespace: demo
spec:
  template:
    metadata:
      annotations:
        # Initial target scale immediately after app is created
        autoscaling.knative.dev/initialScale: "3"
        # Disable scale to zero with a minScale of 1+
        autoscaling.knative.dev/minScale: "2"
        # Limit scaling maximum to 10 pods
        autoscaling.knative.dev/maxScale: "10"
        # Time window which must pass before a scale-down decision is applied
        autoscaling.knative.dev/scaleDownDelay: "5m"
        # Target 10 requests in-flight per pod
        autoscaling.knative.dev/target: "10"
    spec:
      containers:
      - image: gcr.io/knative-samples/helloworld-go
        env:
        - name: TARGET
          value: "World!"