Container Network Interface (CNI) in Kubernetes - Mini Project: Build & Apply

Container Network Interface (CNI) Setup in Kubernetes

📖 Scenario: You are setting up a Kubernetes cluster and need to configure the network so that pods can communicate with each other. This is done using a Container Network Interface (CNI) plugin.In this project, you will create a simple YAML configuration to apply a CNI plugin to your cluster, configure a network range, and verify the network setup.

🎯 Goal: Learn how to apply a CNI plugin configuration in Kubernetes and verify that pods can communicate over the network.

📋 What You'll Learn

Create a YAML manifest for a CNI plugin deployment

Add a network configuration with a specific pod CIDR range

Apply the CNI configuration to the Kubernetes cluster

Verify the network plugin pods are running

💡 Why This Matters

🌍 Real World

Kubernetes clusters need a network plugin to allow pods to communicate. Setting up a CNI plugin like Calico is a common real-world task to enable pod networking.

💼 Career

DevOps engineers and Kubernetes administrators often configure and manage CNI plugins to ensure cluster networking works correctly and securely.

1

Create the CNI Plugin YAML Manifest

Create a YAML file named calico.yaml with the following content to deploy the Calico CNI plugin. Include the apiVersion as projectcalico.org/v3 and kind as Installation. Set the spec.calicoNetwork.ipPools[0].cidr to 192.168.0.0/16.

Kubernetes

# Create calico.yaml with apiVersion, kind, and spec including ipPools cidr
# Your code here

Need a hint?

Use the exact keys apiVersion, kind, and spec.calicoNetwork.ipPools[0].cidr with the given values.

2

Add Network Configuration for Pod CIDR

In the same calico.yaml file, add a spec.kubernetesProvider section with nodePortSupport set to true to enable Kubernetes node port support.

Kubernetes

apiVersion: projectcalico.org/v3
kind: Installation
metadata:
  name: default
spec:
  calicoNetwork:
    ipPools:
    - cidr: 192.168.0.0/16
      encapsulation: VXLAN
      natOutgoing: true
      nodeSelector: all()
# Add kubernetesProvider with nodePortSupport: true below
# Your code here

Need a hint?

Indent kubernetesProvider under spec and set nodePortSupport to true.

3

Apply the CNI Plugin Configuration

Use the command kubectl apply -f calico.yaml to apply the CNI plugin configuration to your Kubernetes cluster.

Kubernetes

# Run the command to apply the calico.yaml configuration
# Your code here

Need a hint?

Type the exact command kubectl apply -f calico.yaml to apply the configuration.

4

Verify the CNI Plugin Pods are Running

Run kubectl get pods -n calico-system and check that the Calico pods have the status Running. Print the output of this command.

Kubernetes

# Run the command to list pods in calico-system namespace
# Your code here

Need a hint?

Use the exact command kubectl get pods -n calico-system to see the status of Calico pods.