kubectl dry-run=server to validate manifests

Use --dry-run=server to validate Kubernetes manifests against the API server without actually creating the resources.

kubectl apply -f deployment.yaml --dry-run=server -o yaml

Why This Matters

• Server-side validation: Checks against admission controllers, webhooks, and API server rules
• Catches real issues: Unlike --dry-run=client, this validates against actual cluster policies
• Safe testing: Preview changes without affecting running resources
• Output inspection: Use -o yaml to see what would be created

Example Use Cases

Validate a deployment before applying

kubectl apply -f deployment.yaml --dry-run=server

Check if a manifest would be accepted

kubectl create -f pod.yaml --dry-run=server -o yaml

Test with different namespaces

kubectl apply -f service.yaml -n production --dry-run=server

Client vs Server Dry Run

• --dry-run=client: Only validates syntax locally
• --dry-run=server: Validates against the actual API server (recommended)

Always use server mode for production validation!