$ cat <<EOF | kubectl apply -f -
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: example-app
  annotations:
    app.oam.dev/revision-only: "true"
spec:
  components:
    - name: testsvc
      type: webservice
      properties:
        addRevisionLabel: true
        image: crccheck/hello-world
        port: 8000
EOF

This will create example-app-v1 AppRevision. Check it:

$ kubectl get applicationrevisions.core.oam.dev
NAME             AGE
example-app-v1   116s

With above annotation this won't create any pod instances.

Then use the above AppRevision to create an AppDeployment.
```
$ kubectl apply -f appdeployment-1.yaml
```
Note that in order to AppDeployment to work, your workload object must have a spec.replicas field for scaling.

Now you can check that there will 1 deployment and 2 pod instances deployed

$ kubectl get deploy
NAME         READY   UP-TO-DATE   AVAILABLE   AGE
testsvc-v1   2/2     2            0           27s

Update Application properties:

$ cat <<EOF | kubectl apply -f -
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: example-app
  annotations:
    app.oam.dev/revision-only: "true"
spec:
  components:
    - name: testsvc
      type: webservice
      properties:
        addRevisionLabel: true
        image: nginx
        port: 80
EOF

This will create a new example-app-v2 AppRevision. Check it:

$ kubectl get applicationrevisions.core.oam.dev
NAME
example-app-v1
example-app-v2

Then use the two AppRevisions to update the AppDeployment:
```
$ kubectl apply -f appdeployment-2.yaml
```
(Optional) If you have Istio installed, you can apply the AppDeployment with traffic split:
```
# set up gateway if not yet
$ kubectl apply -f gateway.yaml

$ kubectl apply -f appdeployment-2-traffic.yaml
```
Note that for traffic split to work, your must set the following pod labels in workload cue templates (see webservice.cue):
```
"app.oam.dev/component": context.name
"app.oam.dev/appRevision": context.appRevision
```

Now you can check that there will 1 deployment and 1 pod per revision.

$ kubectl get deploy
NAME         READY   UP-TO-DATE   AVAILABLE   AGE
testsvc-v1   1/1     1            1           2m14s
testsvc-v2   1/1     1            1           8s

(Optional) To verify traffic split:

# run this in another terminal
$ kubectl -n istio-system port-forward service/istio-ingressgateway 8080:80
Forwarding from 127.0.0.1:8080 -> 8080
Forwarding from [::1]:8080 -> 8080

# The command should return pages of either docker whale or nginx in 50/50
$ curl -H "Host: example-app.example.com" http://localhost:8080/

Cleanup:

kubectl delete appdeployments.core.oam.dev  --all
kubectl delete applications.core.oam.dev --all