kubevela.github.io/versioned_docs/version-v1.1/end-user/workflow/apply-component.md

title
Apply Components and Traits

In this guide, you will learn how to apply components and traits in Workflow.

How to use

Apply the following Application:

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: first-vela-workflow
  namespace: default
spec:
  components:
  - name: express-server
    type: webservice
    properties:
      image: crccheck/hello-world
      port: 8000
    traits:
    - type: ingress
      properties:
        domain: testsvc.example.com
        http:
          /: 8000
  - name: nginx-server
    type: webservice
    properties:
      image: nginx:1.21
      port: 80
  workflow:
    steps:
      - name: express-server
        # specify the workflow step type
        type: apply-component
        properties:
          # specify the component name
          component: express-server
      - name: manual-approval
        # suspend is a built-in task of workflow used to suspend the workflow
        type: suspend
      - name: nginx-server
        type: apply-component
        properties:
          component: nginx-server

If we want to suspend the workflow for manual approval before applying some certain components, we can use suspend step to pause the workflow.

In this case, the workflow will be suspended after applying the first component. The second component will wait to be applied util the resume command is called.

Check the status after applying the Application:

$ kubectl get app first-vela-workflow

NAME                  COMPONENT        TYPE         PHASE                HEALTHY   STATUS   AGE
first-vela-workflow   express-server   webservice   workflowSuspending                      2s

We can use vela workflow resume to resume the workflow.

For more information of vela workflow，please ref vela cli.

$ vela workflow resume first-vela-workflow

Successfully resume workflow: first-vela-workflow

Check the status, the Application is now runningWorkflow:

$ kubectl get app first-vela-workflow

NAME                  COMPONENT        TYPE         PHASE     HEALTHY   STATUS   AGE
first-vela-workflow   express-server   webservice   running   true               10s

Expected outcome

Check the Application status:

kubectl get application first-vela-workflow -o yaml

All the step status in workflow is succeeded:

...
  status:
    workflow:
      ...
      stepIndex: 3
      steps:
      - name: express-server
        phase: succeeded
        resourceRef: {}
        type: apply-component
      - name: manual-approval
        phase: succeeded
        resourceRef: {}
        type: suspend
      - name: nginx-server
        phase: succeeded
        resourceRef: {}
        type: apply-component
      suspend: false
      terminated: true

Check the component status in cluster:

$ kubectl get deployment

NAME             READY   UP-TO-DATE   AVAILABLE   AGE
express-server   1/1     1            1           3m28s
nginx-server     1/1     1            1           3s

$ kubectl get ingress

NAME             CLASS    HOSTS                 ADDRESS   PORTS   AGE
express-server   <none>   testsvc.example.com             80      4m7s

We can see that all the components and traits have been applied to the cluster.