nginx-ingress

Canary deployment using the nginx-ingress controller

In the following example, we shift traffic between 2 applications using the canary annotations of the Nginx ingress controller.

Steps to follow

1. version 1 is serving traffic
2. deploy version 2
3. create a new "canary" ingress with traffic splitting enabled
4. wait enought time to confirm that version 2 is stable and not throwing unexpected errors
5. delete the canary ingress
6. point the main application ingress to send traffic to version 2
7. shutdown version 1

In practice

# Deploy the ingress-nginx controller
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/nginx-0.22.0/deploy/mandatory.yaml

# Expose the ingress-nginx
$ kubectl expose deployment \
    -n ingress-nginx nginx-ingress-controller \
    --port 80 \
    --type LoadBalancer \
    --name ingress-nginx

# Wait for nginx to be running
$ kubectl rollout status deploy nginx-ingress-controller -n ingress-nginx -w
deployment "nginx-ingress-controller" successfully rolled out

# Deploy version 1 and expose the service via an ingress
$ kubectl apply -f ./app-v1.yaml -f ./ingress-v1.yaml

# Deploy version 2
$ kubectl apply -f ./app-v2.yaml

# In a different terminal you can check that requests are responding with version 1
$ nginx_service=$(minikube service ingress-nginx -n ingress-nginx --url)
$ while sleep 0.1; do curl "$nginx_service" -H "Host: my-app.com"; done

# Create a canary ingress in order to split traffic: 90% to v1, 10% to v2
$ kubectl apply -f ./ingress-v2-canary.yaml

# Now you should see that the traffic is being splitted

# When you are happy, delete the canary ingress
$ kubectl delete -f ./ingress-v2-canary.yaml

# Then finish the rollout, set 100% traffic to version 2
$ kubectl apply -f ./ingress-v2.yaml

Cleanup

$ kubectl delete all -l app=my-app