DevOps: Puppet, Docker, and Kubernetes

Scaling your containers

Kubernetes has a scheduler to assign the container to the right node. In addition, you can easily scale out and scale down the number of containers. The Kubernetes scaling function will conduct the replication controller to adjust the number of containers.

Getting ready

Prepare the following YAML file, which is a simple replication controller to launch two nginx containers. Also, service will expose the TCP port 30080:

# cat nginx-rc-svc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: my-nginx
spec:
  replicas: 2
  selector:
      sel : my-selector
  template:
    metadata:
        labels:
          sel : my-selector
    spec:
      containers:
      - name: my-container
        image: nginx
---
apiVersion: v1
kind: Service
metadata:
name: my-nginx