☑️Day 38: Exploring Namespaces in Kubernetes🚀

🔹Table of Contents :

• Introduction

• What are Namespaces?

• Why Use Namespaces?

• Hands-on Learning

• Commands Used

• Real-World Scenario

• Key Learnings

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✅Introduction:

What are Namespaces in Kubernetes?

In Kubernetes, namespaces provide a mechanism to divide a single Kubernetes cluster into multiple virtual clusters. They act as virtual boundaries, allowing you to logically separate resources, users, and services in a cluster. This is particularly useful for large environments or multi-tenant setups.

✅Why Use Namespaces?

• Organizational Separation: Helps divide resources between different teams, projects, or environments (e.g., dev, test, production).

• Resource Allocation: You can set resource limits per namespace, ensuring that one project or team does not consume all the resources.

• Efficient Management: Simplifies managing large clusters by grouping similar workloads together.

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✅How Namespaces Work in Kubernetes

• Each resource in Kubernetes, such as Pods, Services, or Deployments, can be assigned to a specific namespace.

• By default, Kubernetes comes with three pre-defined namespaces:

  • default: Where resources live when no specific namespace is defined.

  • kube-system: Contains all Kubernetes system components.

  • kube-public: Generally used for public access across the cluster.

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✅Hands-On Tasks with Namespaces

Task 1: Creating a New Namespace and Deploying Resources

Scenario:
Imagine your organization has a production and development environment within the same cluster. You want to isolate these environments for easier management.

Steps:

1. Create a new namespace:

   • Command:

       kubectl create namespace dev-environment
     

2. Switch context to the new namespace:

   • Command:

       kubectl config set-context --current --namespace=dev-environment
     

3. Deploy resources (e.g., NGINX Pod) in the new namespace:

   • Create a YAML file (nginx-pod.yaml) for deploying a pod.

       apiVersion: v1
       kind: Pod
       metadata:
         name: nginx-pod
         namespace: dev-environment
       spec:
         containers:
           - name: nginx
             image: nginx:latest
     

   • Apply the file:

       kubectl apply -f nginx-pod.yaml
     

4. Verify the resources deployed in the namespace:

   • Command:

       kubectl get pods -n dev-environment
     

5. Delete the namespace and its resources:

   • Command:

       kubectl delete namespace dev-environment
     

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Task 2: Resource Quotas and Limits on Namespaces

Scenario:
You want to ensure that a particular team doesn’t consume more than a certain amount of resources (e.g., CPU, memory) in a namespace. This is especially important when multiple teams or departments share the same Kubernetes cluster.

Steps:

1. Create a namespace with resource quotas:

   • Command:

       kubectl create namespace prod-environment
     

2. Define resource quota YAML (resource-quota.yaml):

    apiVersion: v1
    kind: ResourceQuota
    metadata:
      name: prod-quota
      namespace: prod-environment
    spec:
      hard:
        pods: "10"
        requests.cpu: "4"
        requests.memory: 10Gi
        limits.cpu: "8"
        limits.memory: 20Gi
   

3. Apply the resource quota to the namespace:

   • Command:

       kubectl apply -f resource-quota.yaml
     

4. Check resource usage in the namespace:

   • Command:

       kubectl get resourcequota -n prod-environment
     

5. Attempt to deploy a pod exceeding the resource limit:

   • If the resources exceed the defined quota, Kubernetes will deny the deployment, ensuring the namespace adheres to the constraints.

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✅Real-World Scenario

Scenario:
A company has two development teams: Frontend and Backend. Both teams share the same Kubernetes cluster but need isolated environments to work independently. They create two separate namespaces: frontend-team and backend-team. Each team deploys resources and services within their namespace without interfering with each other. Additionally, resource quotas are set to avoid resource hogging by one team.

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✅Key Commands for Namespaces

1. List all namespaces:

    kubectl get namespaces
   

2. Create a new namespace:

    kubectl create namespace <namespace-name>
   

3. Set the default namespace for the current context:

    kubectl config set-context --current --namespace=<namespace-name>
   

4. Deploy a pod in a specific namespace (YAML must specify the namespace):

    kubectl apply -f <pod-file>.yaml -n <namespace-name>
   

5. View resources in a specific namespace:

    kubectl get pods -n <namespace-name>
   

6. Delete a namespace:

    kubectl delete namespace <namespace-name>
   

7. Apply resource quota:

    kubectl apply -f resource-quota.yaml -n <namespace-name>
   

8. View resource quotas in a namespace:

    kubectl get resourcequota -n <namespace-name>
   

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✅Key Learnings

Namespaces in Kubernetes provide an effective way to isolate and organize resources within a cluster. Whether you need separate environments for different teams or projects, or want to enforce resource limits, namespaces make managing a Kubernetes cluster simpler and more efficient. Combining namespaces with other Kubernetes features like resource quotas ensures scalability and optimal resource utilization in a multi-team, multi-environment setup.

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🚀Thanks for joining me on Day 38! Let’s keep learning and growing together!

Happy Learning! 😊

#90DaysOfDevOps