danquack / canary-testing

An Application POC to display how with two different containers, you can route traffic via Headers with Istio.

Canary Testing

An Application POC to display how with two different containers, you can route traffic via Headers with Istio.

Running app locally

To run locally simply run: go run main.go /path/to/file

Once running to see the response: curl http://localhost:9000

The application has two endpoints:

/ - returns <File Contents>

/headers - returns headers sent to app

Docker

With the docker image, setting the build arg RES, will create a file with the contents of the value

docker build --build-arg RES=test-a -t canary-testing:a .
docker build --build-arg RES=test-b -t canary-testing:b .

Routing with Virtual Services

With the pod being labeled, with version: canary, you can utilize virtual service and destination rules to route traffic to the new canary.

Define routing subsets:

# Destination Rule
...
    subsets:
    - labels:
        version: canary
      name: canary
    - labels:
        version: production
      name: production

# Virtual Service
...
- name: canary-route
  match:
    - headers:
        version:
          exact: canary
  route:
    - destination:
        host: app-canary-testing
        subset: canary
...

Deploy with Helm

1. Update values.yaml with host, ingress, or any other environment specific information.
2. helm upgrade -n $ISTIO_ENABLED_NAMESPACE app $PWD