What are Namespaces and Services in k8s?

A Namespace is a logical partition within a Kubernetes cluster to isolate and organize resources like Pods, Services, and Deployments. Each Namespace is like a separate cluster within the same physical cluster.

Why Use Namespaces?

• 🧩 Isolation: Separate environments (dev, staging, prod) in one cluster

• 👥 Multi-team support: Different teams or apps don’t interfere with each other

• 🔐 RBAC: Apply access control to specific namespaces

• 📊 Resource quotas: Limit CPU/memory per namespace

What are Services in Kubernetes?

A Service is an abstraction that defines a stable network endpoint for accessing Pods. It ensures communication between components, even when Pods are dynamically created or deleted.

Why Use Services?

• 🔄 Pods have dynamic IPs — Services provide a stable IP and DNS name

• ⚖️ Load Balancing between multiple Pods (via selector)

• 🔒 Service Discovery inside the cluster

Today's task:

Task 1:

• Create a Namespace for your Deployment

• Use the command kubectl create namespace <namespace-name> to create a Namespace

• Update the deployment file to include the Namespace

• Apply the updated deployment using the command: kubectl apply -f deployment.yml -n <namespace-name>

• Verify that the Namespace has been created by checking the status of the Namespaces in your cluster.

Task 2:

• Read about Services, Load Balancing, and Networking in Kubernetes.

1. Service

   • A Service provides a stable network identity (Cluster IP, DNS) to a group of Pods.

   • It load balances traffic across matching Pods using label selectors.

   • Essential for communication between Pods and external access.

2. Networking

   • Each Pod gets its own IP address.

   • All Pods can communicate with each other across Nodes (flat network).

   • Kubernetes uses CNI plugins (like Flannel, Calico) to manage networking.

   • DNS-based service discovery enables Pods to find Services by name.

3. Load Balancing

   • Load balancing happens at two levels:

     • Internal Load Balancing: Service distributes traffic to Pods.

     • External Load Balancing: Service type: Load Balancer provisions a cloud load balancer.

Kubernetes ensures high availability and scalability through automatic load balancing of requests.