Kubernetes Namespaces

Namespaces provide a way to divide cluster resources between multiple users. They are intended for use in environments with many users spread across multiple teams, or projects.

Understanding Namespaces

Purpose of Namespaces

Namespaces allow you to create multiple virtual clusters within the same physical cluster. They help in organizing and managing resources efficiently.

Common Use Cases

  • Environment Separation: Separate development, testing, and production environments.
  • Resource Quotas: Apply resource limits to different teams or projects.
  • Access Control: Implement fine-grained access control using Role-Based Access Control (RBAC).

Managing Namespaces

Creating a Namespace

kubectl create namespace dev

Viewing Namespaces

kubectl get namespaces

Deleting a Namespace

kubectl delete namespace dev

Advanced Namespace Management

Namespaces can be used to implement advanced management strategies:

  • Network Policies: Control traffic flow between namespaces to enhance security.
  • Custom Resource Definitions (CRDs): Use CRDs to extend namespace capabilities with custom resources.
  • Monitoring and Logging: Implement monitoring solutions to track resource usage and access patterns across namespaces.

Example: Network Policies for Namespaces

Network policies can be applied to namespaces to control traffic flow. Here's an example:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-namespace
  namespace: dev
spec:
  podSelector:
    matchLabels: {}
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          name: frontend

This policy allows traffic from Pods in the frontend namespace to Pods in the dev namespace.

Best Practices

  • Consistent Naming: Use a consistent naming convention for namespaces.
  • Limit Resource Usage: Apply resource quotas and limits to manage resource consumption.
  • Regular Audits: Conduct regular audits to ensure compliance with policies.