Demo Deployments

1. Prepare the project structure
2. Create the Deployment manifest
3. Apply the Deployment
4. Verify the rollout and inspect resources

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1. Prepare the directories and files

1. From your project root, create a folder named deployments.
2. Inside deployments, create a file called deployment.yaml.

# replicaset.yaml (for reference)
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: myapp-replicaset
  labels:
    app: myapp
spec:
  selector:
    matchLabels:
      app: myapp
  replicas: 4
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: nginx
        image: nginx

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2. Create the Deployment manifest

• Change kind to Deployment
• Set metadata.name and labels to match your application
• Adjust replicas to 3 (or your desired count)

# deployments/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deployment
  labels:
    tier: frontend
    app: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: nginx
        image: nginx

​

3. Apply the Deployment

kubectl apply -f deployments/deployment.yaml

kubectl create -f deployments/deployment.yaml

​

4. Verify the rollout and inspect resources

1. Check the Deployment status
   kubectl get deployments
   
   Example output:
   NAME               READY   UP-TO-DATE   AVAILABLE   AGE
   myapp-deployment   3/3     3            3           10s
   
2. List the Pods
   kubectl get pods
   
   Example output:
   NAME                                    READY   STATUS    RESTARTS   AGE
   myapp-deployment-5d8fcb5b6c-abc         1/1     Running   0          30s
   myapp-deployment-5d8fcb5b6c-def         1/1     Running   0          30s
   myapp-deployment-5d8fcb5b6c-ghi         1/1     Running   0          30s
   
3. Describe the Deployment
   kubectl describe deployment myapp-deployment
   
   You’ll see details such as desired vs. available replicas, rollout strategy, and recent events:

4. View all objects in the namespace
   kubectl get all
   
   Example output:
   NAME                                   READY   STATUS    RESTARTS   AGE
   pod/myapp-deployment-5d8fcb5b6c-abc    1/1     Running   0          1m
   pod/myapp-deployment-5d8fcb5b6c-def    1/1     Running   0          1m
   pod/myapp-deployment-5d8fcb5b6c-ghi    1/1     Running   0          1m
   
   NAME                     TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
   service/kubernetes       ClusterIP   10.96.0.1      <none>        443/TCP   15m
   
   NAME                               READY   UP-TO-DATE   AVAILABLE   AGE
   deployment.apps/myapp-deployment   3/3     3            3           1m
   
   NAME                                          DESIRED   CURRENT   READY   AGE
   replicaset.apps/myapp-deployment-5d8fcb5b6c   3         3         3       1m
   

kubectl apply -f deployments/deployment.yaml

kubectl rollout status deployment/myapp-deployment

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Links and References

• Kubernetes Deployments
• kubectl Cheat Sheet
• Rolling Updates and Rollbacks