Kubernetes Dashboard Image: A Comprehensive Guide

Kubernetes has revolutionized the way we manage containerized applications at scale. One of the essential tools in the Kubernetes ecosystem is the Kubernetes Dashboard, which provides a web - based user interface for managing and monitoring Kubernetes clusters. The Kubernetes Dashboard image is a pre - built Docker image that contains all the necessary components to run the dashboard. This blog post aims to provide an in - depth understanding of the Kubernetes Dashboard image, including its core concepts, typical usage, common practices, and best practices for intermediate - to - advanced software engineers.

Table of Contents

  1. Core Concepts
  2. Typical Usage Example
  3. Common Practices
  4. Best Practices
  5. Conclusion
  6. References

Core Concepts

What is a Kubernetes Dashboard Image?

The Kubernetes Dashboard image is a Docker image that encapsulates the Kubernetes Dashboard application. It includes all the dependencies, such as the web server, the front - end UI code, and the back - end logic required to interact with the Kubernetes API server. When you deploy the dashboard in your Kubernetes cluster, you are essentially running a container based on this image.

Components within the Image

  • Web Server: Serves the front - end user interface to the users. It handles incoming HTTP requests and renders the dashboard pages.
  • API Client: Communicates with the Kubernetes API server. It fetches information about the cluster resources, such as pods, services, and deployments, and also allows users to perform actions like creating, updating, and deleting resources.
  • Front - End UI: Provides a graphical interface for users to interact with the Kubernetes cluster. It displays various metrics, resource statuses, and allows users to perform administrative tasks.

Image Sources

The official Kubernetes Dashboard image is hosted on Docker Hub (kubernetesui/dashboard). You can also find other community - maintained or customized images on different container registries.

Typical Usage Example

Prerequisites

  • A running Kubernetes cluster. You can use a local cluster like Minikube or a cloud - based cluster such as Google Kubernetes Engine (GKE).
  • kubectl installed and configured to interact with your cluster.

Deployment Steps

  1. Create a Deployment YAML File:
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes - dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin - user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster - admin
subjects:
- kind: ServiceAccount
  name: admin - user
  namespace: kubernetes - dashboard
---
apiVersion: v1
kind: Secret
metadata:
  name: admin - user - token
  namespace: kubernetes - dashboard
  annotations:
    kubernetes.io/service - account.name: admin - user
type: kubernetes.io/service - account - token
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: kubernetes - dashboard
  namespace: kubernetes - dashboard
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s - app: kubernetes - dashboard
  template:
    metadata:
      labels:
        k8s - app: kubernetes - dashboard
    spec:
      containers:
      - name: kubernetes - dashboard
        image: kubernetesui/dashboard:v2.7.0
        ports:
        - containerPort: 8443
        args:
          - --auto - generate - certificates
  1. Apply the YAML File:
kubectl apply -f dashboard - deployment.yaml
  1. Access the Dashboard: First, get the token for the admin - user service account:
kubectl -n kubernetes - dashboard get secret $(kubectl -n kubernetes - dashboard get sa/admin - user - o jsonpath="{.secrets[0].name}") - o go - template="{{.data.token | base64decode}}"

Then, start a proxy to access the dashboard:

kubectl proxy

Finally, open your browser and navigate to http://localhost:8001/api/v1/namespaces/kubernetes - dashboard/services/https:kubernetes - dashboard:/proxy/. Enter the token you obtained earlier to log in.

Common Practices

Security Considerations

  • Role - Based Access Control (RBAC): Use RBAC to define who can access the dashboard and what actions they can perform. In the example above, we created a ClusterRoleBinding for the admin - user service account, but you can create more restrictive roles for regular users.
  • HTTPS: Always use HTTPS to secure the communication between the user’s browser and the dashboard. The official image supports auto - generating certificates, but in a production environment, you should use proper TLS certificates.

Monitoring and Logging

  • Integrate with Monitoring Tools: Connect the dashboard to monitoring tools like Prometheus and Grafana to get more detailed metrics about the cluster and the dashboard itself.
  • Centralized Logging: Use a centralized logging solution like Elasticsearch, Fluentd, and Kibana (EFK stack) to collect and analyze the dashboard logs.

Best Practices

Image Version Management

  • Stay Up - to - Date: Regularly update the Kubernetes Dashboard image to the latest stable version to get the latest security patches and features.
  • Test Before Upgrading: Before upgrading the image in a production environment, test the new version in a staging or development cluster to ensure compatibility.

Customization

  • Customize the UI: You can customize the dashboard UI by modifying the CSS and JavaScript files. However, make sure to follow the official documentation and best practices to avoid breaking the functionality.
  • Extend Functionality: Use the Kubernetes API to extend the dashboard’s functionality. For example, you can create custom plugins to display additional information or perform specific actions.

Conclusion

The Kubernetes Dashboard image is a powerful tool for managing and monitoring Kubernetes clusters. By understanding its core concepts, typical usage, common practices, and best practices, intermediate - to - advanced software engineers can effectively deploy and use the dashboard in their environments. Remember to prioritize security, stay up - to - date with image versions, and customize the dashboard to meet your specific needs.

References