Active-Proxy is a dynamic reverse proxy written in Go.
It uses etcd to dynamically switch application upstreams without restarting.
This is just an experiment, so any feature that you could think of is probably missed. Pull requests are really appreciated.
This repository includes a vagrant file with a box that already includes the latest stable version of etcd.
Use vagrant up to boot the box. The server listens then at localhost:8080.
It uses gopack to install other required dependencies when the project builds.
You can build it running:
$ ./gopack build
Or run it from source using:
$ script/server
Imagine that you have an applications called foo and bar that you want to server from the same port.
foo runs on http://localhost:4000/foo and bar runs on http://localhost:5000/bar.
You can make Active-Proxy to run both on :8080/foo and :8080/bar registering them in the etcd cluster:
$ curl -L http://127.0.0.1:8080/v1/keys/applications/foo/port -d value=4000
$ curl -L http://127.0.0.1:8080/v1/keys/applications/bar/port -d value=5000
Imagine then that you want to redeploy foo. You can boot the new code in a different port, tell Active-Proxy to serve new requests through that port and kill the old application.
There are no complicated hotdeploy strategies required and it allows you to test that the application boots correctly before switching ports.
You only need to register the new port in the etcd cluster and Active-Proxy will do the switch for you without restarting the proxy either:
$ curl -L http://127.0.0.1:8080/v1/keys/applications/foo/port -d value=4004