k8s

Purpose

This skill enables the AI to orchestrate and manage containerized applications using Kubernetes, focusing on scaling, deployment, and maintenance of pods, services, and deployments in a cluster.

When to Use

Use this skill for deploying multi-container apps, scaling workloads dynamically, managing resources in production environments, or troubleshooting cluster issues. Apply it when handling container orchestration beyond basic Docker, such as in CI/CD pipelines or microservices architectures.

Key Capabilities

• Deploy and manage pods using YAML manifests or imperative commands.

• Scale applications with deployments and replicasets, e.g., autoscaling based on CPU metrics.

• Expose services via ClusterIP, NodePort, or LoadBalancer types.

• Handle storage with PersistentVolumes and PersistentVolumeClaims.

• Monitor and debug resources using built-in tools like kubectl logs and events.

• Integrate with networking plugins for service discovery and load balancing.

• Manage secrets and config maps for secure configuration.

Usage Patterns

Always authenticate with a valid kubeconfig file, set via the $KUBECONFIG environment variable. For declarative setups, write YAML files and apply them; for imperative tasks, use kubectl directly. Pattern: Load context with kubectl config use-context my-context , then perform actions. Include error checks in scripts, e.g., verify command exit codes.

Example 1: Deploy a simple Nginx pod.

• Create a pod: kubectl run nginx-pod --image=nginx --port=80

• Expose it: kubectl expose pod nginx-pod --type=NodePort --port=80

• Verify: kubectl get pods -l run=nginx-pod

Example 2: Scale a deployment.

• Apply a deployment YAML: kubectl apply -f deployment.yaml

• Where deployment.yaml contains: apiVersion: apps/v1 kind: Deployment metadata: name: my-app spec: replicas: 3 selector: matchLabels: app: my-app template: metadata: labels: app: my-app spec: containers: - name: my-container image: my-image

• Scale it: kubectl scale deployment my-app --replicas=5

• Check status: kubectl get deployments my-app

Common Commands/API

Use kubectl for CLI interactions; for API access, target the Kubernetes API server at endpoints like /api/v1/pods. Always specify namespaces with --namespace flag if needed.

• Get resources: kubectl get pods --namespace=default -o wide (flags: -o for output format, --namespace for scope)

• Create resources: kubectl apply -f pod.yaml --record (flags: -f for file, --record for history)

• Delete resources: kubectl delete deployment my-app --cascade=foreground (flags: --cascade for dependent cleanup)

• Update resources: kubectl set image deployment/my-app my-container=my-image:new-tag

• API endpoints: Use curl with authentication, e.g., curl -k -H "Authorization: Bearer $KUBE_TOKEN" https://api.example.com/api/v1/namespaces/default/pods

• Config formats: YAML for manifests, e.g., apiVersion: v1 kind: Pod metadata: name: example spec: containers: - name: example image: nginx

• Environment setup: Export $KUBECONFIG=/path/to/config for authentication.

Integration Notes

Integrate Kubernetes with other tools via the Kubernetes API or operators. For authentication, use $KUBECONFIG for kubeconfig files or $KUBE_API_KEY for API tokens. Pattern: In scripts, check if $KUBECONFIG is set; if not, prompt or error out. For CI/CD, use tools like Argo CD or Jenkins plugins; example: Helm charts for packaging, installed via helm install my-chart ./chart-dir . Ensure compatibility with cloud providers like AWS EKS by setting provider-specific configs in kubeconfig.

Error Handling

Always check kubectl exit codes; if non-zero, use kubectl describe <resource> for details. Common errors: "NotFound" for missing resources—handle by checking existence first with kubectl get ; "Forbidden" for permissions—verify RBAC roles. In code, wrap commands in try-catch blocks, e.g., in Python: import subprocess; try: subprocess.run(['kubectl', 'get', 'pods'], check=True) except subprocess.CalledProcessError as e: print(f"Error: {e}") . For API calls, handle HTTP errors like 403 or 500 by retrying with exponential backoff. Log events with kubectl get events --namespace=default to diagnose issues.

Graph Relationships

• Related to cluster: devops-sre (e.g., links to other devops skills like CI/CD tools).

• Connected via tags: kubernetes (e.g., relates to container management skills), k8s (synonym for kubernetes), containers (links to Docker or orchestration skills).

• Potential edges: This skill depends on networking and storage skills; it provides outputs for monitoring skills like Prometheus.