redeploy-operator

Kubernetes Redeploy Operator to redeploy pods in a deployment in the form of rolling updates.

This project is built with help of Operator-SDK.

How it works

Redeploy Operator basically adds a label to PodSpec field in deployments. This triggers a deployment rollout. Type of rollout depends on MaxSurge and MaxUnavailable fields in your deployments.

The label you will see added is the datetime (UTC) field. Eg: redeployed: 2018-08-07-05_28_41

Limitations:

1. It only works for deployments. ( Statefulsets, replicasets and daemonsets are not covered. )

Installation

1. Install CRD, rbac and operator.

kubectl apply -f deploy/crd.yaml
kubectl apply -f deploy/rbac.yaml
kubectl apply -f deploy/operator.yaml

2. Install a demo app:

kubectl create namespace nginx
kubectl run nginx --namespace nginx --image nginx:alpine --replicas=2

3. Trigger a redeploy:

kubectl apply -f deploy/cr.yaml

4. See it work:

kubectl -n nginx get pods -w
kubectl -n redeploy-operator logs -l name=redeploy-operator

5. Check status

   1. Check the custom resource.

   kubectl -n redeploy-operator get redeploies -o yaml

   You should see RedeployNeeded set to false and status fields appended.

   spec:
     DeploymentName: nginx
     DeploymentNamespace: nginx
     RedeployNeeded: false
   status:
     Date: 2018-08-07-05_28_41
     Status: REDEPLOYED
   

   2. Check the deployment

   kubectl -n nginx get deployment nginx -o yaml | grep redeployed

    redeployed: 2018-08-07-05_28_41
   

Building from source:

1. Install Operator-SDK
2. operator-sdk generate k8s
3. operator-sdk build <IMAGE-NAME>
4. docker push <IMAGE-NAME>

Note: operator.yaml is custom built. It is overwritten upon building the project. Please make necessary changes to make it work.