Painless zero-downtime redeploys for simple apps.
rainbowd.js is a small reverse proxy. You tell it how to launch your app on a given port and with a given pidfile, and it will handle gracefully moving traffic to a new process and killing the old one when it comes time to redeploy. This is still in alpha stages, so proceed at your own risk!
The graceful shutdown is enitrely dependent on the underlying webserver providing a graceful shutdown.
No current plans to support websockets.
Written with node-http-proxy.
Provide:
- A command that takes a server port and launches the current release on that port
- Either:
- A healthcheck url (suggested)
- A warmup time (careful! Setting this too low could cause downtime)
Get back:
- A proxy of your app on 0.0.0.0:7000
- Zero downtime deploys by doing
curl -d '' 127.0.0.1:7001/redeploy(note this only listens on the loopback address).- Note that this API is will change soon. The rest API will gain some type of security token, and the default will be to disallow API redeploys and use something else file-based so it's easier to restrict by Linux users and groups.
It will launch the service on a new available port, only send new connections to the new service, and send SIGTERM to the old service, which hopefully will trigger a graceful shutdown.
This is intended to run beind another reverse proxy. The idea is if you're already pointing e.g. Apache or Nginx to your app server, you point them to rainbowd.js instead.
This is a lightweight blue-green deploy system. But it's not limited to just two concurrent versions: supposing the responses are slow and/or the deploys happen fast enough, it can keep an arbitrary number (well, up to a hard limit of 10) running. This is where the name comes from.
- [ ] Test with various Python and Ruby servers.
- [ ] Command-line flag for config file
- [ ] Allow control and server port/addr to be configurable
- [ ] Allow a touch file(?) for redeploy to make redeploy easier/more secure
- [ ] Option to disable REST API