KodeKloud Notes

In this guide, you'll learn how to create a Kubernetes Deployment manifest to deploy your Docker image on Google Kubernetes Engine (GKE). We’ll cover:

Creating a Git branch
Writing the Deployment manifest
Understanding each field in the YAML
Next steps for automated deployment

Prerequisites

A working GKE cluster
kubectl configured to talk to your GKE cluster
Docker image pushed to a container registry (e.g., Google Container Registry)

1. Create a New Git Branch

Open your terminal, ensure you’re on main, then create a feature branch:

$ git branch
* main
$ git checkout -b minor/deployment-file
Switched to a new branch 'minor/deployment-file'
$ git branch
  main
* minor/deployment-file

Note

Make sure you have committed or stashed any local changes before switching branches.

You can confirm the active branch in your IDE’s integrated terminal.

2. Define the Deployment Manifest

In the root of your project, create a file named GKE.yaml. This manifest tells Kubernetes how many replicas to run, which Docker image to use, and which port to expose.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gcp-devops-gke
spec:
  replicas: 1
  selector:
    matchLabels:
      app: gcp
  template:
    metadata:
      labels:
        app: gcp
    spec:
      containers:
        - name: gcp-devops-gke
          image: gcr.io/kodekloud-gcp-training/test-gcpdevops:latest
          ports:
            - containerPort: 5000
          env:
            - name: PORT
              value: "5000"

3. Manifest Field Reference

Below is a quick reference for the key fields in GKE.yaml:

Field	Description	Example
apiVersion	Kubernetes API version for the Deployment resource	`apps/v1`
kind	Resource type	`Deployment`
metadata.name	Unique name for your Deployment	`gcp-devops-gke`
spec.replicas	Number of pod replicas to maintain	`1`
spec.selector.matchLabels	Label selector matching pods managed by this Deployment	`app: gcp`
spec.template.metadata.labels	Labels applied to each pod	`app: gcp`
spec.template.spec.containers	Container definitions including image, ports, and env variables	name, image URL, `containerPort: 5000`, env `PORT=5000`

4. Verify and Apply the Manifest

Once GKE.yaml is saved, apply it to your GKE cluster:

$ kubectl apply -f GKE.yaml
deployment.apps/gcp-devops-gke created

Check the rollout status:

$ kubectl rollout status deployment/gcp-devops-gke

Warning

Always review your manifest for correct image tags and port configurations before applying to production clusters.

5. Next Steps

Now that your Deployment manifest is live, update your CI/CD pipeline to automate this step. For example, extend your cloudbuild.yaml to:

Build and push the Docker image
Run kubectl apply -f GKE.yaml against your GKE cluster

This ensures every merge to main automatically deploys the latest version.

Links and References

Watch Video

Watch video content