devops-exercises/topics/argo/exercises/blue_green_rollout/solution.md

Argo Rollouts - Blue/Green

Requirements

1. Running Kubernetes cluster
2. Argo Rollouts CLI
3. Deployed app in specific version

Objectives

1. Install Argo Rollouts controller
2. Write a rollout manifest that use blue/green deployment and apply it
   1. Set it to 3 replicas
   2. Disable auto-promotions
3. Check the rollout list
4. Rollout a new version of your app in any way you prefer
   1. Check the status of the rollout

Solution

Installation:

1. kubectl create namespace argo-rollouts

   1. kubectl apply -n argo-rollouts -f https://github.com/argoproj/argo-rollouts/releases/latest/download/install.yaml

2. Rollout resource:

---
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: some-app
spec:
  replicas: 3
  strategy:
    blueGreen:     
      autoPromotionEnabled: false
  selector:
    matchLabels:
      app: some-web-app
  template:
    metadata:
      labels:
        app: some-web-app
    spec:
      containers:
      - name: web-app
        image: some/registry/and/image:v1.0
        ports:
        - name: http
          containerPort: 8080
          protocol: TCP

3. kubectl argo rollouts list rollouts
4. kubectl argo rollouts set image SOME-APP web-app=some/registry/and/image:v2.0
   1. kubectl argo rollouts get rollout some-app --watch