Kubernetes

Concepts

Decoupling:

• run resources anywhere
• don't tie an application to a specific server
• don't store configuration within the application

Usage

# Create a deployment of 3 nginx services called "salesweb"
kubectl create deployment salesweb --image=nginx:latest --replicas=3
# Create a service for the salesweb deployment to use port 80 inside the containers 
kubectl expose deployment salesweb --port=80
# Tell the ingress controller to redirect any traffic (including sub-paths) on "sales.example.com" to the salesweb service
kubectl create ingress salesweb --rule="sales.example.com/*=salesweb:80"

Tips and Tricks

Don't write YAML files directly, generate them. Use kubectl create with the options --dry-run=client -o yaml to generate the YAML files. Alternatively, use a kubectl get command with -o yaml. Use kubectl apply -f to create or update resources from a YAML file.