Sivakumar Vunnam

Argocd

Oct 1, 2022 • Sivakumar Vunnam

CLI Usage

argo list                                # List workflows

argo submit [--watch] myworkflow.yaml    # Create workflow
argo submit myworkflow.yaml -p foo=bar   # Create workflow with parameters
argo submit myworkflow.yaml --parameter-file config.yaml
argo submit myworkflow.yaml --entry-point "my-command"

argo logs <pod>                          # Show workflow log
argo delete <pod>                        # Delete workflow
argo delete --all                        # Delete all workflows

You can also use kubectl

kubectl get wf             # List workflows
kubectl delete wf <name>   # Delete workflow

Simple Workflow

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: [""]
      resources:                # limit the resources
        limits:
          memory: 32Mi
          cpu: 100m

Multi-Step Workflow

apiVersion: argoproj.io/v1alpha1
kind: Workflow
[...]
spec:
  [...]
  templates:
  - name: my-template
    steps:
    - - name: step1           # <- Note the list in list structure!
        template: [...]
        arguments:
          parameters: 
            - [...]
    - - name: step2a
        [...]
      - name: step2b
        [...]

Execution of the defined steps happens by traversing the list tree. All elements of a tree leaf run in parallel while the first level list does define the steps sequence.

Steps with Loops

steps:
- - name: print-message
    template: whalesay
    arguments:
      parameters:
      - name: message
        value: ""
    withItems:              # invoke whalesay once for each item in parallel
    - hello world           # item 1
    - goodbye world         # item 2

## Steps: Conditional Execution

 steps:
    # flip a coin
    - - name: flip-coin
        template: flip-coin
    # evaluate the result in parallel
    - - name: heads
        template: heads                 # call heads template if "heads"
        when: " == heads"
      - name: tails
        template: tails                 # call tails template if "tails"
        when: " == tails"

Steps: Running scripts

spec:
  templates:
  - name: flip-coin
    script:
      image: python:alpine3.6
      command: [python]
      source: |
        import random
        result = "heads" if random.randint(0,1) == 0 else "tails"
        print(result)