How to Create a Simple Pod in Kubernetes¶

This guide will walk you through creating and managing pods in Kubernetes. A pod is the smallest deployable unit in Kubernetes that can be created and managed.

Prerequisites¶

Kubernetes cluster (Minikube or any other cluster)
kubectl installed and configured
Basic understanding of YAML

Creating Your First Pod¶

Method 1: Using YAML File (Recommended)¶

Create a file named my-first-pod.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  containers:
  - name: nginx
    image: nginx:latest
    ports:
    - containerPort: 80

Apply the configuration:
```
kubectl apply -f my-first-pod.yaml
```

Method 2: Using Command Line¶

# Create a pod directly from command line
kubectl run nginx-pod --image=nginx:latest --port=80

Verifying Pod Creation¶

# List all pods
kubectl get pods

# Get detailed information about the pod
kubectl describe pod nginx-pod

# View pod logs
kubectl logs nginx-pod

# Get pod details in YAML format
kubectl get pod nginx-pod -o yaml

Pod with Multiple Containers¶

Create a file named multi-container-pod.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: multi-container-pod
spec:
  containers:
  - name: nginx
    image: nginx:latest
    ports:
    - containerPort: 80
  - name: redis
    image: redis:latest
    ports:
    - containerPort: 6379

Apply the configuration:

kubectl apply -f multi-container-pod.yaml

Pod with Resource Limits¶

Create a file named pod-with-resources.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: resource-limited-pod
spec:
  containers:
  - name: nginx
    image: nginx:latest
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"

Pod with Environment Variables¶

Create a file named pod-with-env.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: pod-with-env
spec:
  containers:
  - name: nginx
    image: nginx:latest
    env:
    - name: DB_HOST
      value: "mysql-service"
    - name: DB_PORT
      value: "3306"

Accessing the Pod¶

# Port forward to access the pod locally
kubectl port-forward nginx-pod 8080:80

# Execute commands inside the pod
kubectl exec -it nginx-pod -- /bin/bash

# Copy files to/from pod
kubectl cp nginx-pod:/etc/nginx/nginx.conf ./nginx.conf

Pod Lifecycle Management¶

# Delete a pod
kubectl delete pod nginx-pod

# Delete using YAML file
kubectl delete -f my-first-pod.yaml

# Force delete a pod
kubectl delete pod nginx-pod --grace-period=0 --force

Pod Health Checks¶

Create a file named pod-with-probes.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: pod-with-probes
spec:
  containers:
  - name: nginx
    image: nginx:latest
    livenessProbe:
      httpGet:
        path: /
        port: 80
      initialDelaySeconds: 3
      periodSeconds: 3
    readinessProbe:
      httpGet:
        path: /
        port: 80
      initialDelaySeconds: 5
      periodSeconds: 5

Troubleshooting Pods¶

Common Issues and Solutions¶

Pod in Pending State

# Check pod status
kubectl describe pod nginx-pod

# Check node resources
kubectl describe nodes

Pod in CrashLoopBackOff

# Check pod logs
kubectl logs nginx-pod

# Check previous container logs
kubectl logs nginx-pod --previous

Pod in ImagePullBackOff

# Check image name and registry access
kubectl describe pod nginx-pod

Best Practices¶

Resource Management
Always specify resource requests and limits
Monitor resource usage
Use appropriate container images
Health Checks
Implement liveness and readiness probes
Set appropriate timing for probes
Use proper probe types (HTTP, TCP, Command)
Labels and Annotations
Use meaningful labels
Follow naming conventions
Document with annotations
Security
Use non-root users
Implement security contexts
Use read-only root filesystem when possible

Example: Complete Production-Ready Pod¶

apiVersion: v1
kind: Pod
metadata:
  name: production-pod
  labels:
    app: web
    environment: production
  annotations:
    description: "Production web server pod"
spec:
  containers:
  - name: nginx
    image: nginx:latest
    ports:
    - containerPort: 80
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"
    livenessProbe:
      httpGet:
        path: /healthz
        port: 80
      initialDelaySeconds: 3
      periodSeconds: 3
    readinessProbe:
      httpGet:
        path: /ready
        port: 80
      initialDelaySeconds: 5
      periodSeconds: 5
    securityContext:
      runAsNonRoot: true
      runAsUser: 1000
      readOnlyRootFilesystem: true
    volumeMounts:
    - name: config-volume
      mountPath: /etc/nginx/conf.d
  volumes:
  - name: config-volume
    configMap:
      name: nginx-config

Next Steps¶

Learn about Deployments
Explore Services
Study pod networking
Implement pod security policies