Rack::Revision

Rack::Revision is a quick drop-in component to enable code revision tracking. It adds X-Revision header with the code revision from capistrano's REVISION file.

Installation

Add dependency to your Gemfile:

gem "rack-revision"

Install gem:

bundle install

Usage

Rack::Revision is implemented as a piece of Rack middleware and can be used with any Rack-based application. If you have a config.ru rackup file you can drop the following snippet (for sinatra app):

require "rack/revision"

# Basic example
use Rack::Revision

# With custom revision header
use Rack::Revision, :header => "X-CODE-VERSION"

# With custom filename and default value
use Rack::Revision, :filename => ".version", :default => "n/a"

# Execute application
run Sinatra::Application

Available options:

:header - Changes revision header name. Default: X-Revision
:filename - Changes the revision filename. Default: REVISION
:rack_env - Changes Rack environment key for revision. Default: env['rack.app_revision']
:env_var - Sets revision value from an environment variable. Default: RACK_REVISION
:default - Sets revision value if env var or a file with revision does not exist. Default: UNDEFINED

Example

To see what the header might look like, run a curl command:

curl -i -X HEAD "http://yourdomain.com"

Example response:

HTTP/1.1 200 OK
Server: nginx/1.4.4
Content-Type: text/html; charset=utf-8
Connection: keep-alive
X-UA-Compatible: IE=Edge,chrome=1
ETag: "5e622b6dab40d3cb8ad8a4bd51627a59"
Cache-Control: max-age=0, private, must-revalidate
X-Request-Id: ae07ad30bd857788bebfa1421576f96e
X-Runtime: 0.022007
X-Rack-Cache: miss
X-Revision: a3de2043d4cea6182e511c9c73f57f4f1e0dbc2b

Test

Execute test suite:

rake test

License

The MIT License

rack-revision