api-gw-example

This is a sample project to demonstrate API Gateway principles with Kong.

Target architecture

                                                   +------------+
                                                   |            |
                                                   |  ImagesApi |
                                             +---> |            |
                                             |     |            |
                                             |     +------------+
+----------+    /images   +-----------       |
|          |              |          |       |
|          |              |          |       |
|   LB     +------------> |   Kong   +-------+
|          |              |          |       |
|          |              |          |       |     +------------+
+----------+    /products +----------+       |     |            |
                                             |     |   Products |
                                             +---> |   API      |
                                                   |            |
                                                   +------------+

Pre-requisites

You need to have a running Kontena platform. We'll go and deploy everything into Kontena.

Kong

In this sample setup, we're using Kong as the API Gateway component. Kong needs to be up-and-running before deploying the sample APIs.

Deploy Kong

kontena stack install kontena/kong

Just follow the stack installation wizard

Demo APIs

In this repo I've hard-coded the images to use my personal repo jnummelin in Docker Hub.

If you wish to fine-tune the app, fork this repo and give your own image name in kontena.yml.

The sample API deployments handle registering the APIs to Kong using the admin API and Kontena post_start deployment hooks.

Deploy Images API

Deployment as usually for Kontena stacks:

$ cd images-api
$ kontena stack install

Deploy Products API

Deployment as usually for Kontena stacks:

$ cd products-api
$ kontena stack install

Add rate limit

There's a rake task for setting a simple rate limit for the /products API. The limit is hard-coded for 5 reqs per minute, just to easily show how rate-limits and other plugins can be easily configured.

$ kontena service exec product-api/api rails kong:rate_limit

Now when you hit the /products API the 6th time within a minute you'll get:

$ curl -vv demo-api.kontena.works/products/foobar
> GET /products/ab8f5275-3350 HTTP/1.1
> Host: demo-api.kontena.works
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 429
< Date: Mon, 30 Oct 2017 13:34:51 GMT
< Content-Type: application/json; charset=utf-8
< Transfer-Encoding: chunked
< X-RateLimit-Limit-minute: 5
< X-RateLimit-Remaining-minute: 0
< Server: kong/0.11.1
<
{"message":"API rate limit exceeded"}