Coding Cloud

Deploy a K8s Service

MD
R
Markdown

A service is an abstraction to access Replication Controllers containers outside of the cluster. Service Types: a) ClusterIp (internal IP) b) NodePort (public IP) c) LoadBalancer (NodePort to cloud based LB) Some background: - Client will connect to RCs or Pods? No - Client will connect to a Service (IP,DNS,Port are stable) - Remind that RCs and Pods are Ephemeral and Unstable. - Remind also that Pods run in Nodes (minions) - Pods are connected to Services via LABELS - A Service is basically a label selector - A Service contains a Load Balancer - A Service has built-in Service Discovery by DNS based Outcomes of creating a service: - Endpoint Docs: https://kubernetes.io/docs/concepts/services-networking/service/

Create a Service from an RC

kubectl expose rc sampleapp-rc --name=sampleapp-svc --target-port=80 --type=NodePort

Cross check the newly created service

kubectl describe svc sampleapp-svc NodePort: <unset> 31903/TCP kubectl cluster-info https://192.168.64.2:8443/ Port range will always be: 30000 / 32767

Get the Cluster Public IP Address

kubectl cluster-info minikube service sampleapp-svc --url

List all Services

kubectl get svc

Delete a Service

kubectl delete svc sampleapp-svc

Declare a Service

kind: Service
apiVersion: v1
metadata:
  name: sampleapp-svc
  labels:
    app: sampleapp
spec:
  type: NodePort
  ports:
  - port: 80
    nodePort: 30001
    protocol: TCP
  selector:
    app: sampleapp

Load yml into apiServer

kubectl create -f svc-blueprint.yml

Cross check

kubectl get svc kubectl describe svc sampleapp-svc

Open in browser

kubectl cluster-info chrome http://192.168.64.2:30001/

Created on 5/21/2018