What are Services

Services: A Service is an abstract way to expose an application running on a set of Pods as a network service. This gives your application a single, stable entry point.

Service Types: There are different types of services for different purposes.

ClusterIP: Exposes the service on a cluster-internal IP. This is the default and is only reachable from within the cluster.

NodePort: Exposes the service on each Node's IP at a static port (the NodePort). This makes the service accessible from outside the cluster.

LoadBalancer: Exposes the service externally using a cloud provider's load balancer. This is the most common way to expose an application on a public cloud.

ExternalName: Maps the service to a DNS name.

Labels and Selectors: Services use selectors to determine which Pods they should route traffic to. This is where the labels you added to your Deployment and Pods come into play. A Service with the app: nginx selector will automatically load balance traffic to all Pods with that same label.

Step 1: Create a Namespace

A namespace helps organize and isolate Kubernetes resources.

Run:

kubectl create namespace my-namespace

Replace my-namespace with a name of your choice (e.g., day33-ns).
To verify:

kubectl get namespaces

Step 2: Update Your Deployment YAML

Edit your deployment.yml and add the namespace field at the top level:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: my-namespace   # <-- add this line
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80

Step 3: Apply Deployment in the Namespace

kubectl apply -f deployment.yml -n my-namespace

Step 4: Verify Resources in the Namespace

Check deployments:

kubectl get deployments -n my-namespace

Check pods:

kubectl get pods -n my-namespace

Step 5: Understand Services

Services allow your Pods to be accessed inside or outside the cluster.

• ClusterIP (default): Exposes the service only within the cluster.
• NodePort: Exposes the service on each Node’s IP at a static port.
• LoadBalancer: Exposes the service externally using a cloud provider’s load balancer.

Example Service YAML (to expose Nginx Deployment):

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
  namespace: my-namespace
spec:
  selector:
    app: nginx
  ports:
  - protocol: TCP
    port: 80        # Service port
    targetPort: 80  # Pod containerPort
  type: NodePort    # Can be ClusterIP / NodePort / LoadBalancer

Apply:

kubectl apply -f service.yml -n my-namespace

Check service:

kubectl get svc -n my-namespace

Now your Nginx Deployment is running in its own namespace and exposed via a Service.