knative-route-demo

Your map to help you navigate the Knative routes. Simple blue/green-like app deployment pattern demo.

Setup

Stand up an instance of Knative using latest build

Demo

Once the Knative cluster has been successfully deployed we can move on to the actual demo. The demo will be done entirely using pre-build images so there is no need to deal with dependencies or go builds unless you want to (see Rebuilding Images section below)

Note, for this demo I'm gonna use thingz.io domain which I defined in Google Domains. To use another domain edit domain ConfigMap in econfig-domain.yaml and kubectl replace -f updated-file.yaml to use a different domain.

Deploy app (blue)

kubectl apply -f deployments/stage1.yaml

Check for external IP being assigned in k8s ingress service

kubectl get ing

When route created and IP assigned, navigate to http://route-demo.default.thingz.io to show deployed app. Let's call this blue (aka v1) version of the app.

Deploy new (green) version of the app

kubectl apply -f deployments/stage2.yaml

This will only stage v2. That means:

Won't route any of v1 (blue) traffic to that new (green) version, and
Create new named route (v2) for testing of new the newlly deployed version

Refresh v1 (http://route-demo.default.thingz.io) to show our v2 takes no traffic, and navigate to http://v2.route-demo.default.thingz.io to show the new v2 named route.

Migrate portion of v1 (blew) traffic to v2 (green)

kubectl apply -f deployments/stage3.yaml

Refresh (a few times) the original route http://route-demo.default.thingz.io to show part of traffic going to v2

Note, demo uses 50/50 split to assure you don't have to refresh too much, normally you would start with 1-2% maybe

Re-route 100% of traffic to v2 (green)

kubectl apply -f deployments/stage4.yaml

This will complete the deployment by sending all traffic to the new (green) version.

Refresh original route http://route-demo.default.thingz.io bunch of times to show that all traffic goes to v2 (green) and v1 (blue) no longer takes traffic.

Optionally, I like to pointing out that:

I kept v1 (blue) entry with 0% traffic for speed of reverting, if ever necessary
I added named route v1 to the old (blue) version of the app to allow access for comp reasons

Navigate to http://v1.route-demo.default.thingz.io to show the old version accessible by v1 named route

Rebuilding Images

Install app on the Knative service first you have to create an image of the app. You can build the image using GCP image build service by executing make push command. If successful, the IMAGES column from the results will include the URI of your image. If you need to update the image change containerSpec portion of the stage1.yaml and stage2.yaml manifest to your new image URI.

serviceType: container
      containerSpec:
        image: gcr.io/knative-samples/knative-route-demo:blue

Configuring DNS

Wait for the ingress to obtain a public IP, sometime takes up to 30sec.

kubectl get ing

Then capture that IP using below command and configure an A entry with * in your DNS server to point your that IP

Cleanup

kubectl delete -f deployments/stage4.yaml --ignore-not-found=true
kubectl delete -f deployments/stage3.yaml --ignore-not-found=true
kubectl delete -f deployments/stage2.yaml --ignore-not-found=true
kubectl delete -f deployments/stage1.yaml --ignore-not-found=true

chhsia0/knative-route-demo