Sure, here are some more detailed examples of what you can build to understand Kubernetes:
1. Deploying a Simple Web Application
- Build a Docker image for a simple web application
- Create a Kubernetes Deployment manifest to deploy the application with a specified number of replicas
- Create a Kubernetes Service manifest to expose the application within the cluster
- Test the application by accessing it via the Service's ClusterIP
2. Scaling the Web Application
- Update the Deployment manifest to increase the number of replicas
- Observe the behavior of the Kubernetes scheduler as it deploys new replicas
- Use the Kubernetes dashboard or CLI to view the status of the Deployment and its replicas
3. Updating the Web Application
- Build a new Docker image with updated code or configuration
- Update the Deployment manifest to use the new image version
- Observe the Kubernetes rollout process as it updates the Deployment replicas to the new image
- Test the updated application by accessing it via the Service's ClusterIP
4. Rolling Back the Web Application
- Update the Deployment manifest to use a previous image version
- Use the Kubernetes rollout commands to trigger a rollback to the previous version
- Observe the Kubernetes rollout process as it updates the Deployment replicas to the previous image
- Test the rolled-back application by accessing it via the Service's ClusterIP
5. Creating a Multi-Tier Application
- Build Docker images for a frontend web application, backend API, and database
- Create Kubernetes Deployment manifests for each component, specifying labels and selectors for inter-component communication
- Create Kubernetes Service manifests for each component to expose them within the cluster
- Use the Kubernetes dashboard or CLI to view the status of the Deployments and their replicas
6. Configuring Ingress and Network Policies
- Create a Kubernetes Ingress manifest to expose the frontend service to the outside world
- Configure a Kubernetes NetworkPolicy manifest to restrict traffic between the frontend and backend services
- Test the application's connectivity by accessing it via the Ingress's external IP address
7. Using Persistent Volumes
- Create a Kubernetes PersistentVolume manifest to provision a storage volume on a local or remote disk
- Create a Kubernetes PersistentVolumeClaim manifest to request a storage volume with a specific size and access mode
- Modify the Deployment manifest to use the PersistentVolumeClaim for data storage
- Test the application's data persistence by deleting and recreating the Deployment and observing that data is retained
8. Monitoring and Logging
- Deploy a Prometheus server and Grafana dashboard to monitor Kubernetes metrics and application performance
- Deploy an Elasticsearch, Fluentd, and Kibana (EFK) stack to collect and analyze Kubernetes logs Use the dashboards and logs to diagnose issues and optimize application performance
9. Autoscaling and Load Balancing
- Configure Kubernetes HorizontalPodAutoscaler (HPA) manifests to scale the number of replicas based on CPU or custom metrics
- Deploy a Kubernetes LoadBalancer Service manifest to distribute incoming traffic to multiple replicas
- Test the application's scalability by generating load and observing that new replicas are automatically deployed
10. Advanced Concepts
- Configure a Kubernetes cluster with multiple master nodes for high availability
- Implement Kubernetes role-based access control (RBAC) and namespaces to isolate and secure different applications and teams
- Create custom resource definitions (CRDs) to extend Kubernetes with custom objects and APIs
- Create Kubernetes Operators to automate application deployment and management, using tools like Operator SDK and KUDO.