Create a workflow

Background information

Based on Argo, the workflows developed by Alibaba Cloud provide containerized workflows for Alibaba Cloud Container Service for Kubernetes. Specifically, a workflow is implemented as a Kubernetes Custom Resource Definition (CRD). As such, you can use kubectl to manage workflows, and integrate them with other Kubernetes services, such as volumes, Secrets, and Role-Based Access Control (RBAC). At the backend, the workflow controller provides complete workflow features such as parameter substitution, artifacts, fixtures, loops, and recursive workflows.

Prerequisites

• A Kubernetes cluster is created. For more information, see Create a Kubernetes cluster.
• The Master node of the Kubernetes cluster is accessible. For more information, see Connect to a Kubernetes cluster by using kubectl.

Procedure

• Use the Container Service console to create a workflow named Hello World
  1. Log on to the Container Service console.
  2. In the left-side navigation pane under Container Service-Kubernetes, choose Applications > Workflow.
  3. In the upper-right corner, click Create by Template.
  4. Set the template parameters.
     • Clusters: Select the target cluster.
     • Namespaces: Select the target namespace. The default namespace is used.
     • Sample Template: Select a sample YAML template or customize a YAML template.
       Note Alibaba Cloud Container Service for Kubernetes offers you with the sample YAML templates of various resources.
     
     
     
     The following is a sample YAML template of the workflow named Hello World:

     apiVersion: argoproj.io/v1alpha1
     kind: Workflow                  # new type of k8s spec
     metadata:
       generateName: hello-world-    # name of the workflow spec
     spec:
       entrypoint: whalesay          # invoke the whalesay template
       templates:
       - name: whalesay              # name of the template
         container:
           image: docker/whalesay
           command: [cowsay]
           args: ["hello world"]
           resources:                # limit the resources
             limits:
               memory: 32Mi
               cpu: 100m

  5. Click DEPLOY.
  6. On the Workflow page, find the target workflow. Then, in the Action column, click Details to view the overview and container group information of the workflow.
     
     
• Use the command line interface (CLI) to create a workflow named Parameters
  Note Ags CLI is a CLI tool customized by Alibaba Cloud. This tool is compatible to Argo. With Ags CLI, you can submit, check, modify, and delete workflows. For more information, see Introduction to AGS CLI.
  1. Create the file arguments-parameters.yaml, and then copy the following code to the file:

     apiVersion: argoproj.io/v1alpha1
     kind: Workflow
     metadata:
       generateName: hello-world-parameters-
     spec:
       # invoke the whalesay template with
       # "hello world" as the argument
       # to the message parameter
       entrypoint: whalesay
       arguments:
         parameters:
         - name: message
           value: hello world
     
       templates:
       - name: whalesay
         inputs:
           parameters:
           - name: message       # parameter declaration
         container:
           # run cowsay with that message input parameter as args
           image: docker/whalesay
           command: [cowsay]
           args: ["{{inputs.parameters.message}}"]

  2. Run the ags submit arguments-parameters.yaml -p message="goodbye world" command.

You can create more workflows by modifying the sample workflow templates. For more information, see Sample workflow templates.