Introduction to Kubernetes

Docker Philadelphia September 27, 2016

Ross Kukulinski ross@kukulinski.com

Getting Started

You need a Kubernetes cluster to play with. minikube is a great way to get started.

Hello World

cd helloworld

less index.js

less package.json

npm install

node index.js

curl http://127.0.0.1:3000

curl http://127.0.0.1:3000/version

http://127.0.0.1:3000/healthz

Building Containers with Docker

less Dockerfile

docker build -t rosskukulinski/helloworld:v1.0.0 .

docker images

docker push rosskukulinski/helloworld:v1.0.0

Deploying Containers with Kubernetes

kubectl run helloworld --image=rosskukulinski/helloworld:v1.0.0 --port=3000 --port 8000 --replicas=3 --labels=app=helloworld

kubectl get pods

kubectl describe pods <pod>

Running Adhoc Commands

kubectl exec <pod> -c helloworld -- node -v

Logs

kubectl logs -f <pod> redis

Port Forwarding

Terminal 1

kubectl port-forward <pod> 5000:3000

Terminal 2

curl http://127.0.0.1:5000

Scaling out

kubectl scale deployment/helloworld --replicas=5

kubectl get pods

Service Discovery

less svc/helloworld.yml

kubectl create -f svc/helloworld.yml

kubectl describe svc helloworld

kubectl run busybox --image=odise/busybox-curl sleep 600

kubectl exec -ti <pod-name> /bin/sh

curl helloworld

curl helloworld/version

curl http://<lb-public-ip>/

Rolling Update

while true; do curl http://<lb-public-ip>/version; sleep .5; done

kubectl edit deployment/helloworld

kubectl rollout undo deployment/helloworld

Skip These

less deployments/helloworld-v1.yml

kubectl create -f deployments/helloworld-v1.yml

kubectl describe deployments/helloworld

curl http://<podip>

Troubleshooting

kubectl get pods

kubectl label pods <pod> track-

kubectl label pods <pod> track=stable

Canary Pattern

less deployments/helloworld-canary.yml

kubectl create -f deployments/helloworld-canary.yml

kubectl get pods

while true; do curl http://<lb-public-ip>/version; sleep .5; done

Label Queries

kubectl get pods

kubectl get pods -l app=helloworld,track=stable

kubectl get pods -l app=helloworld,track=canary

Rolling Updates

less deployments/helloworld-v2.yml

kubectl apply -f deployments/helloworld-v2.yml

kubectl rollout history deployment/helloworld

kubectl rollout undo deployment/helloworld