rolling-updates.md

Rolling Updates

• Use multiple replication controllers with a single service
• Deploy a canary application for testing
• Zero downtime rolling update to a new Docker image

Send the Canary

cat hello-canary-controller.json 

kubecfg -c hello-canary-controller.json create replicationControllers

Validation

kubecfg list pods

Try hitting the service port on any of the knode instances.

gcloud compute instances list

while true; do curl http://${EXTERNAL_IP}; echo; sleep 2; done

Did you find the canary?

Rolling Update

kubecfg get replicationControllers/helloStableController

kubecfg list pods

Open three terminals

Terminal 1

kubecfg --image "quay.io/kelseyhightower/hello:2.0.0" rollingupdate helloStableController

Terminal 2

while true; do curl http://${EXTERNAL_IP}; echo; sleep 2; done

Terminal 3

kubecfg list pods