This project is a simple example of API Gateway pattern for microservices implemented in Node.js.
It's not production-ready service and its sole purpose is to demonstrate usage of node-docker-monitor and http-proxy npm modules.
Service reacts on Docker events and as Docker containers go up and down, it creates or removes HTTP routing rules for them. To indicate that a container is to be handled by the gateway it must have label api_route defining URL prefix for that container plus it must EXPOSE port that containerised service listens on.
To be able to monitor local Docker instance, we need to make UNIX socket /var/run/docker.sock available to the container.
docker run -d --name api-gateway -v /var/run/docker.sock:/var/run/docker.sock -p 80:8080 beh01der/docker-api-gateway-example
An upstream service can be started with command similar to (depending on your service implementation)
docker run -d --name service1 -e SERVICE_NAME=service1 -l=api_route='/service1' --expose 3000 beh01der/web-service-dockerized-example
When upstream service containers are being discovered we should see output like
$ docker logs api-gateway
Registered new api route: {"apiRoute":"/service1","upstreamUrl":"http://172.17.0.2:3000"}
Registered new api route: {"apiRoute":"/service2","upstreamUrl":"http://172.17.0.3:3000"}
Now, we can test it
$ curl 127.0.0.1/service1
Hello World!
I am service 1!