Blue-Green Deployments with Spinnaker
External
Internal
Overview
This article documents a pipeline that deploys a release in a Stage environment, waits for testing, the deploys the same release in Prod. The application is a Helm-packaged Kubernetes application, but some of the Kubernetes resources, such as Services, are created manually directly in Spinnaker and others are added specifically for Spinnaker (ReplicaSets instead of Deployments)
Create Services
Create two Services ("stage" and "prod") within the Spinnaker Application.
Load Balancers → Create Load Balancer
Select the right "account" (Kubernetes cluster)
Manifest (do not forget to adjust the namespace):
apiVersion: v1
kind: Service
metadata:
name: stage
namespace: of02
spec:
type: ClusterIP
selector:
stage: 'true' # this label will be dynamically applied to the workload pods
ports:
- port: 8080
name: http
targetPort: 8080
apiVersion: v1
kind: Service
metadata:
name: prod
namespace: of02
spec:
type: ClusterIP
selector:
prod: 'true' # this label will be dynamically applied to the workload pods
ports:
- port: 8080
name: http
targetPort: 8080
Create the Pipeline
It will be a "deploy to stage → manual testing → manual judgement → deploy to prod" pipeline.
Name: "Stage - Manual Testing - Prod" (no "→" allowed in name)
Add stage → Bake (Manifest). Stage name: "Render Helm Chart". This stage will render the helm chart, apply the configuration overlay and overwrite the image tag. For more details, see:
Add stage → Deploy (Manifest). Stage name: "Deploy in Stage". This stage will deploy the Helm chart and associate the workload with the "stage" service. For more details, see:
At this stage, we do enable Rollout Strategy Options, so we can associate the workload with the "stage" service.
Enable: "Spinnaker manages traffic based on your selected strategy" → Service(s) Namespace → Service(s): "stage" → Traffic: Send client requests to new pods → Strategy: "None". ⚠️ "None" is mandatory here, other strategy might delete production.
Link to detailed explanations of what happens for each of the rollout strategies from the point of view of 1) services 2) replicasets 3) pods.
Add stage → Manual Judgement. Stage name: "Wait on Stage Testing"
Add stage → Deploy (Manifest). Stage name: "Deploy in Prod". This stage will deploy the same Helm chart that was tested in Stage and associate the workload with the "prod" service. For more details, see:
At this stage, we do enable Rollout Strategy Options:
Enable: "Spinnaker manages traffic based on your selected strategy"
Organizatorium
TO PROCESS:
- https://blog.spinnaker.io/introducing-rollout-strategies-in-the-kubernetes-v2-provider-8bbffea109a
- https://spinnaker.io/docs/guides/user/kubernetes-v2/rollout-strategies/#redblack-rollouts
- https://spinnaker.io/docs/guides/user/kubernetes-v2/traffic-management/
- https://www.opsmx.com/blog/spinnaker-pipeline-blue-green-strategy-with-external-versioning-and-kubernetes-deployment-object/
- https://www.opsmx.com/blog/spinnaker-integration-with-istio/