Scale up and Rollback

The ability to roll your application forward and back, to be able to provision new pods or roll back to a previous state is an important one. Modern applications are living breathing entities; as deployment occurs issues may arise during the initial phase of the release and require fixing. This functionality of rolling back to a good known state is important and critical for any modern software delivery system. Kubernetes provides the ability to scale up known good applications, as well as roll them back to previous versions. This functionality is exposed in Armory Enterprise and is walked through in this next module.

Create pipeline “Deploy Apple”

Before we scale up and rollback, we need to deploy the application we will use by creating a pipeline. The simple application that we will deploy displays the fruit name “Apple”. We will be deploying a new version of the application that displays the fruit name “Banana”. In order to provide external access to the applications, the deployment will include an Ingress. You will find the ingress endpoint in the Armory Enterprise UI which you will enter in the address field of your browser. In this section you will also update the application by making a siple modification to the yaml.

  1. Navigate to “Pipelines” and in the top right, click the ‘+ Create’ icon (or “+”, depending on the size of your browser)
  2. Give the pipeline the name Deploy Apple
  3. Click “Add Stage”, select type “Deploy (Manifest)” and Stage Name is Deploy Apple
  4. Under “Account” choose “spinnaker”
  5. Check “Override Namespace” and select “dev” as the namespace
  6. Copy and paste the following manifest YAML and click “Save Changes” 
    apiVersion: apps/v1
kind: Deployment
metadata:
  name: apple-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: apple
  template:
    metadata:
      labels:
        app: apple
        lb: apple
    spec:
      containers:
        - image: hashicorp/http-echo
          args:
           - "-text=apple"
          name: apple-app
---
apiVersion: v1
kind: Service
metadata:
  name: apple-service
spec:
  selector:
    app: apple
  ports:
    - port: 5678 # Default port for image
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - http:
      paths:
        - path: /apple
          backend:
            serviceName: apple-service
            servicePort: 5678

Trigger pipeline and navigate to Apple app

  1. Navigate to “Pipelines” screen and start manual execution of “Deploy Apple” pipeline
  2. Once completed visit “Load Balancers” screen and find the ingress of the apple deployment “ingress example-ingress” and select dev namespace. Then on the right side find Ingress URL. When clicking on the ingress, you should expect to get a 404. To access the apple app, you have to append /apple to the end of the ingress URL.

Update pipeline to automatically update the version

Next we are going to update the YAML and Spinnaker is going to automatically update the version

  1. Click “Configure” on the “Deploy Apple” pipeline
  2. Change the ’-text=apple’ under image for the deployment to ’-text=banana’ and save changes. Execute the pipeline
  3. Doing so will create a new version of the deployment
  4. Visit the ingress with the /apple path appended and see that the app is now displaying the word banana.