argo-cd/workflows/bluegreen.yaml

# This example demonstrates a "blue-green" deployment
apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: k8s-bluegreen-
spec:
  entrypoint: k8s-bluegreen
  arguments:
    parameters:
    - name: deployment-name
    - name: service-name
    - name: new-deployment-manifest
  templates:
  - name: k8s-bluegreen
    steps:
    # 1. Create a parallel Kubernetes deployment with tweaks to name and app name
    - - name: create-blue-deployment
        template: clone-deployment
        arguments:
          parameters:
          - name: green-deployment-name
            value: '{{workflow.parameters.deployment-name}}'
          - name: suffix
            value: blue

    # 2. Wait for parallel deployment to become ready
    - - name: wait-for-blue-deployment
        template: wait-deployment-ready
        arguments:
          parameters:
          - name: deployment-name
            value: '{{steps.create-blue-deployment.outputs.parameters.blue-deployment-name}}'

    # 3. Patch the named service to point to the parallel deployment app
    - - name: switch-service-to-blue-deployment
        template: patch-service
        arguments:
          parameters:
          - name: service-name
            value: '{{workflow.parameters.service-name}}'
          - name: app-name
            value: '{{steps.create-blue-deployment.outputs.parameters.blue-deployment-app-name}}'

    # 4. Update the original deployment (receiving no traffic) with a new version
    - - name: create-green-deployment
        template: patch-deployment
        arguments:
          parameters:
          - name: deployment-manifest-data
            value: '{{workflow.parameters.new-deployment-manifest}}'

    # 5. Wait for the original deployment, now updated, to become ready
    - - name: wait-for-green-deployment
        template: wait-deployment-ready
        arguments:
          parameters:
          - name: deployment-name
            value: '{{steps.create-green-deployment.outputs.parameters.green-deployment-name}}'

    # 6. Patch the named service to point to the original, now updated app
    - - name: switch-service-to-green-deployment
        template: patch-service
        arguments:
          parameters:
          - name: service-name
            value: '{{workflow.parameters.service-name}}'
          - name: app-name
            value: '{{steps.create-green-deployment.outputs.parameters.green-deployment-app-name}}'

    # 7. Remove the cloned deployment (no longer receiving traffic)
    - - name: delete-cloned-deployment
        template: delete-deployment
        arguments:
          parameters:
          - name: deployment-name
            value: '{{steps.create-blue-deployment.outputs.parameters.blue-deployment-name}}'

# end of steps




  - name: clone-deployment
    inputs:
      parameters:
      - name: green-deployment-name
      - name: suffix
    container:
      image: argoproj/argoexec:latest
      command: [sh, -c]
      args: ["
          kubectl get -o json deployments/{{inputs.parameters.green-deployment-name}} | jq -c '.metadata.name+=\"-{{inputs.parameters.suffix}}\" | (.metadata.labels.app, .spec.selector.matchLabels.app, .spec.template.metadata.labels.app) +=\"-{{inputs.parameters.suffix}}\"' | kubectl create -o json -f - > /tmp/blue-deployment;
          jq -j .metadata.name /tmp/blue-deployment > /tmp/blue-deployment-name;
          jq -j .spec.template.metadata.labels.app /tmp/blue-deployment > /tmp/blue-deployment-app-name
      "]
    outputs:
      parameters:
      - name: blue-deployment-name
        valueFrom:
          path: /tmp/blue-deployment-name
      - name: blue-deployment-app-name
        valueFrom:
          path: /tmp/blue-deployment-app-name

  - name: patch-deployment
    inputs:
      parameters:
      - name: deployment-manifest-data
    container:
      image: argoproj/argoexec:latest
      command: [sh, -c]
      args: ["
          echo '{{inputs.parameters.deployment-manifest-data}}' | kubectl apply -o json -f - > /tmp/green-deployment;
          jq -j .metadata.name /tmp/green-deployment > /tmp/green-deployment-name;
          jq -j .spec.template.metadata.labels.app /tmp/green-deployment > /tmp/green-deployment-app-name
      "]
    outputs:
      parameters:
      - name: green-deployment-name
        valueFrom:
          path: /tmp/green-deployment-name
      - name: green-deployment-app-name
        valueFrom:
          path: /tmp/green-deployment-app-name

  - name: wait-deployment-ready
    inputs:
      parameters:
      - name: deployment-name
    container:
      image: argoproj/argoexec:latest
      command: [sh, -c]
      args: ["kubectl rollout status --watch=true 'deployments/{{inputs.parameters.deployment-name}}'"]

  - name: patch-service
    inputs:
      parameters:
      - name: service-name
      - name: app-name
    container:
      image: argoproj/argoexec:latest
      command: [sh, -c]
      args: ["kubectl patch service '{{inputs.parameters.service-name}}' -p '{\"spec\": {\"selector\": {\"app\": \"{{inputs.parameters.app-name}}\"}}}'"]

  - name: delete-deployment
    inputs:
      parameters:
      - name: deployment-name
    resource:
      action: delete
      manifest: |
        apiVersion: apps/v1
        kind: Deployment
        metadata:
          name: {{inputs.parameters.deployment-name}}