kubevela/docs/examples/imagepulljob

This example shows how to use imagePullJob as a workflow step in an application deployment.

Install Definitions

install openkruise: vela addon enable kruise or install openkruise manully helm install kruise https://github.com/openkruise/kruise/releases/download/v0.9.0/kruise-chart.tgz --set featureGates="PreDownloadImageForInPlaceUpdate=true" kubectl apply -f kubevela/vela-templates/addons/kruise/definitions/imagepulljob-step.yaml

Pre-download workflow step should be installed successfully at present. Check Component and Workflow definitions: kubectl get workflowstep

Output: NAME AGE predownloadimage 49s

Install another workflow step that need to be performed after pre-download image: kubectl apply -f applydemo-definition.yaml

apply(Nginx) workflow step should be installed successfully at present. Check Component and Workflow definitions: kubectl get workflowstep

Output: NAME AGE predownloadimage 49s apply 49s

Begin The Workflow Demo

This Demo is to apply pull image for nginx first and that start a nginx application.

1. Apply Application:

   kubectl apply -f basic_image_pull.yaml
   

2. Check workflow status in Application:

   kubectl get application pullimage-sample -o yaml
   

   Output:

   ...
   apiVersion: core.oam.dev/v1beta1
   kind: Application
   metadata:
     ...
   spec:
     components:
     - name: nginx
       properties:
         image: nginx:1.9.1
         port: 80
       type: webservice
     workflow:
       steps:
       - name: pullimage
         properties:
           image: nginx:1.9.1
           kvs:
             kubernetes.io/os: linux
           parallel: 3
         type: predownloadimage
       - name: deploy-remaining
         properties:
           component: nginx
         type: apply
   status:
     ...
     services:
     - healthy: true
       name: nginx
       workloadDefinition:
         apiVersion: apps/v1
         kind: Deployment
     status: running
     workflow:
       appRevision: pullimage-sample-v1
       contextBackend:
         kind: ConfigMap
         name: workflow-pullimage-sample-v1
       stepIndex: 2
       steps:
       - name: pullimage
         phase: succeeded
         resourceRef: {}
         type: predownloadimage
       - name: deploy-remaining
         phase: succeeded
         resourceRef: {}
         type: apply
       suspend: false
       terminated: true
   

   In Above "workflow:" fields. you can see that two steps all in phase succeeded, which means these two steps have been performed successfully.

3. Check Resource in cluster.

   kubectl get imagepulljob
   kubectl get pods
   

   Output:

   NAME             TOTAL   ACTIVE   SUCCEED   FAILED   AGE   MESSAGE
   pull-image-job   3       0        3         0        19s   job is running, progress 0.0%
   

   NAME                      READY   STATUS    RESTARTS   AGE
   nginx-868d6c9dc7-kmgvs    1/1     Running   0          55s
   

The above step shows how to use workflow step to start a deployment.