Capistrano deployment with S3

We recently started using Capistrano for our deployments. It's a great tool and really simplifies doing remote deployments to ec2.

A lot of our projects are java, or java web projects, so we need to deploy the result of a build, not the raw source. I really didn't want to store builds alongside the source code in subversion. Before capistrano, I had written a couple of install shell scripts that would fetch the latest project binary from S3, using bucket names structure like:

${RELEASE_BUCKET}:${PROJECT}/${VERSION} 

with current always pointing to the latest version.

There is a capistrano-s3 project that checks out from your scm, creates a .tar.gz, pushes this to s3, and then pushes this to your servers.

This isn't exactly what I wanted, since it's still missing a build step. I thought I could get by with something pretty simple -- just a scm implementation backed by S3. It turns out it was pretty easy.

Here's the S3 scm implementation. You need to have s3sync installed. Drop this in

$GEMPATH/capistrano-2.0.0/lib/capistrano/recipes/deploy/scm

And you can now use the following:

set :scm, :s3
set :repository, "my-bucket:my-path"

by default it will look in my-bucket:my-path/current/, you can also set

set :branch, "1.12"

and it will look in my-bucket:my-path/1.12/

If your AWS keys aren't available in the environment for s3sync, you can also set these in your capfile:

set :access_key, "my key"
set :secret_key, "my secret"

That's basically it. I'm pretty new to both capistrano and ruby, so any comments, feedback, etc. would be appreciated.