Kubernetes Cheat Sheet 2025: YAML, CLI & Concepts From Beginner to Advanced

☸️ Kubernetes Cheat Sheet 2025: YAML, CLI & Concepts From Beginner to Advanced

Kubernetes (K8s) is now the backbone of cloud-native infrastructure. Whether you’re deploying a simple app or running enterprise-scale microservices, knowing Kubernetes is no longer optional — it’s essential.

This cheat sheet is your one-stop guide — from basic YAML templates and kubectl commands to architecture, scaling, security, and beyond.

Let’s dive in. Bookmark this — you’ll use it often!

🔹 Section 1: What Is Kubernetes?

Kubernetes is an open-source container orchestration platform that helps manage:

Deployments
Scaling
Networking
Monitoring
Self-healing of containerized applications

It runs workloads using Pods, manages traffic using Services, and scales using Controllers.

🧱 Section 2: Kubernetes Architecture – Key Components

Component	Description
Pod	Smallest deployable unit; contains one or more containers
Node	A physical or virtual machine running pods
Cluster	Set of worker nodes managed by the control plane
Deployment	Manages stateless application versions and scaling
Service	Provides stable networking to Pods
Ingress	Routes external traffic to services via URL rules
ConfigMap / Secret	Injects configuration or sensitive data into pods
Namespace	Isolates resources in a multi-tenant cluster

📄 Section 3: Common YAML Templates

✅ Pod

apiVersion: v1
kind: Pod
metadata:
  name: mypod
spec:
  containers:
    - name: myapp
      image: nginx

✅ Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
        - name: web
          image: nginx

✅ Service

apiVersion: v1
kind: Service
metadata:
  name: web-service
spec:
  type: NodePort
  selector:
    app: web
  ports:
    - port: 80
      targetPort: 80

✅ Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: app-ingress
spec:
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web-service
                port:
                  number: 80

💻 Section 4: kubectl CLI – Cheat Sheet Commands

🔍 Get Information

kubectl get pods                # List pods
kubectl get svc                 # List services
kubectl get nodes               # List nodes
kubectl get deployments         # List deployments
kubectl describe pod <pod>      # Details of a pod

🛠 Manage Resources

kubectl apply -f app.yaml       # Create or update resources
kubectl delete -f app.yaml      # Delete resources
kubectl rollout restart deployment <name>  # Restart a deployment

🚪 Logs & Debugging

kubectl logs <pod-name>         # View logs
kubectl exec -it <pod> -- bash  # Enter container shell
kubectl top pods                # View resource usage

📦 Namespace Management

kubectl get ns                  # List namespaces
kubectl config set-context --current --namespace=my-namespace

📦 Section 5: Configs, Secrets & Environment

✅ ConfigMap

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  APP_MODE: "production"

✅ Secret

apiVersion: v1
kind: Secret
metadata:
  name: db-secret
type: Opaque
data:
  DB_PASSWORD: cGFzc3dvcmQ=    # base64 encoded

✅ Use in Pod

envFrom:
  - configMapRef:
      name: app-config
  - secretRef:
      name: db-secret

🚀 Section 6: Scaling & Auto-Healing

Feature	Command
Manual Scaling	`kubectl scale deployment webapp --replicas=5`
Auto Scaling	Enable with HPA: `kubectl autoscale deployment webapp --min=2 --max=10 --cpu-percent=80`
Self-Healing	If a pod crashes, Kubernetes restarts it automatically

🧠 Section 7: Advanced Concepts & Tools

Feature	Use Case
Helm	Package manager for Kubernetes apps (Charts)
Kustomize	Manage environment-specific configs
ArgoCD / Flux	GitOps-style continuous deployment
HPA/VPA	Autoscale pods based on CPU, memory
CRD	Extend Kubernetes API with custom resources
Operators	Automate complex application management (e.g., DBs, queues)

🔐 Section 8: Security & Best Practices

Feature	Purpose
RBAC	Control who can access what in the cluster
Network Policies	Control pod-to-pod communication
Pod Security	Limit privileged containers
Secret Management	Encrypt sensitive data
Admission Controllers	Validate/modify requests at runtime

📊 Section 9: Observability – Logs, Metrics, Traces

Tool	Function
Prometheus	Collect metrics
Grafana	Visualize data
Loki	Centralize logs
Jaeger	Trace requests
ELK Stack	Log aggregation & search

📚 Section 10: Learning & Certification Resources

Resource	Description
kubernetes.io/docs	Official documentation
Play with Kubernetes	Interactive sandbox
KodeKloud	Labs & CKA practice
TechWorld with Nana	Best YouTube channel
CKA Certification	Become a Certified K8s Admin

🏁 Final Thoughts

Kubernetes may look complex at first, but this cheat sheet breaks it down into:

🧱 Architecture — Know what parts make the system
📄 YAML — Define your app’s desired state
💻 kubectl — Control the system with ease
🛡 Security & Observability — Production readiness
🚀 Advanced Tools — Helm, ArgoCD, CRDs, GitOps

Learn once. Practice often. Use everywhere.

Kubernetes is not just a trend — it’s the operating system of the cloud.

Mohammad Gufran Jahangir