Google Kubernetes Engine app authentication example

A sample rack application deployed to Google Kubernetes Engine (GKE). To demonstrate how Google Cloud Endpoints can be used to implement API key based authentication for the backend.

Routing flow:

Running in Production

If you already have cluster setup you can push your app image to the container registery.

gcloud builds submit -t gcr.io/PROJECT-ID/rack-app

And deploy that to GKE using deployment.yml file. You need to setup a new Cloud Endpoint and configure service account roles for ESP. Instructions are given in the following link. https://cloud.google.com/endpoints/docs/openapi/get-started-kubernetes-engine

Sample application reads two paths.

/ (root path)
/hello (authentication is applied on this path using API_KEY)

Once everyting is running you can make the following request.

curl "http://IP_ADDRESS:80/hello"

You should be able to see the following message.

{
   "message":"UNAUTHENTICATED:Method doesn't allow unregistered callers (callers without established identity). Please use API Key or other form of API consumer identity to call this API.",
   "code":401
}

Now generate an api key from API & Services section in the console or use an existing one. Call the endpoint again.

curl "http://IP_ADDRESS:80/hello?key=${API_KEY}"

It should authenticate successfully and respond.

{"message":"Hello World! - 127.0.0.1"}

Blog Post URL: https://medium.com/@ajaz.farhad19/implementing-api-key-based-authentication-for-a-ruby-rack-application-deployed-on-google-kubernetes-b5d0a7ddc22a