Demo Managing a rolling update on GKE cluster

In this tutorial, you’ll learn how to perform and manage rolling updates on a Google Kubernetes Engine (GKE) cluster. These concepts apply equally to upstream Kubernetes, enabling you to update container images with zero downtime and perform safe rollbacks when needed.

Prerequisites

Google Cloud SDK with gcloud and kubectl installed
A Google Cloud project with billing enabled
Enable the Kubernetes Engine API

1. Configure and Create the Cluster

First, set your Compute Engine zone and create a single-node GKE cluster named gke-deep-dive.

# Set your desired zone
gcloud config set compute/zone us-west1-a

# Create a cluster with one node
gcloud container clusters create gke-deep-dive \
  --num-nodes=1 \
  --machine-type=e2-medium \
  --disk-type=pd-standard \
  --disk-size=10

Cluster provisioning can take a few minutes. You can monitor progress in the Google Cloud Console under Kubernetes Engine > Clusters.

2. Deploy a Simple Nginx Application

Create a Deployment manifest gke-deep-dive-app.yaml with two replicas of Nginx:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

Apply the manifest and verify the pods:

kubectl apply -f gke-deep-dive-app.yaml
kubectl get deployments
kubectl get pods

RESOURCE TYPE	COMMAND	DESCRIPTION
Deployment	`kubectl apply -f gke-deep-dive-app.yaml`	Create or update the deployment
Pods	`kubectl get pods`	List running pods and their status

3. Perform Rolling Updates

GKE supports in-place rolling updates, ensuring that at least one replica remains available while others are replaced.

Action	Command	Description
Update image	`kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1`	Change the container image to 1.9.1
Monitor rollout	`kubectl rollout status deployment/nginx-deployment`	Wait until the rollout completes

3.1 Update to Nginx 1.9.1

kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1
kubectl rollout status deployment/nginx-deployment

Verify the new pods are running:

kubectl get pods

3.2 Update to Nginx 1.21.0

Perform another image update to observe an in-progress rollout:

kubectl set image deployment/nginx-deployment nginx=nginx:1.21.0
kubectl rollout status deployment/nginx-deployment

4. Rollback a Deployment

If a rollout introduces an issue, you can revert to a previous revision.

4.1 Rollback to the Previous Revision

kubectl rollout undo deployment/nginx-deployment
kubectl describe deployment/nginx-deployment | grep Image

4.2 Rollback to a Specific Revision

View rollout history:

kubectl rollout history deployment/nginx-deployment

Roll back to revision 1 (original version):

kubectl rollout undo deployment/nginx-deployment --to-revision=1
kubectl describe deployment/nginx-deployment | grep Image

Rolling back to a previous revision may disrupt your application. Always test in a staging environment before rolling back in production.

Introduction

High Level Overview

Playground Instructions

GKE Deployment and Administration

Networking for GKE clusters

Managing Security Aspects

Plan, Deploy And Manage Workloads On GKE

GKE Design Considerations

It’s a wrap

Demo Managing a rolling update on GKE cluster

Prerequisites

1. Configure and Create the Cluster

2. Deploy a Simple Nginx Application

3. Perform Rolling Updates

3.1 Update to Nginx 1.9.1

3.2 Update to Nginx 1.21.0

4. Rollback a Deployment

4.1 Rollback to the Previous Revision

4.2 Rollback to a Specific Revision

Links and References

Watch Video

​Prerequisites

​1. Configure and Create the Cluster

​2. Deploy a Simple Nginx Application

​3. Perform Rolling Updates

​3.1 Update to Nginx 1.9.1

​3.2 Update to Nginx 1.21.0

​4. Rollback a Deployment

​4.1 Rollback to the Previous Revision

​4.2 Rollback to a Specific Revision

​Links and References

Watch Video

Prerequisites

1. Configure and Create the Cluster

2. Deploy a Simple Nginx Application

3. Perform Rolling Updates

3.1 Update to Nginx 1.9.1

3.2 Update to Nginx 1.21.0

4. Rollback a Deployment

4.1 Rollback to the Previous Revision

4.2 Rollback to a Specific Revision

Links and References