Rake tasks from a Rubygem

While recently working on IronHide, specifically the CouchDB Adapter, I needed a way to have the gem expose custom Rake tasks to an end user’s application.

For example, to make working with the IronHide CouchDB Adapter easier, I wanted to allow users to upload existing rules from disk to a remote CouchDB database.

The task could be something as simple as:

$ bundle exec rake iron_hide:load_rules\['/absolute/path/file.json',''\]

where the two arguments are the path to the JSON file and the remote CouchDB database.

Bundler #

After thinking for a moment, I knew that I’ve come across at least one gem that when included, exposes Rake tasks that I can use in my project, Bundler. So, I started looking through the source and found this: https://github.com/bundler/bundler/blob/master/lib/bundler/gem_helper.rb

Essentially, you’d like an application owner to be able to “install” a few Rake tasks at their convenience. Borrowing from the Bundler project:

# iron_hide/couchdb_tasks.rb
module IronHide
  class CouchDbTasks
    include Rake::DSL if defined? Rake::DSL

    def install_tasks
      namespace :iron_hide do
        desc 'Load rules from local JSON file to remote CouchDB server'
        task :load_rules, :file, :db_server do |t, args|


Now, in my application’s Rakefile I just need to add this line:

# Rakefile
require 'iron_hide/couchdb_tasks'

Et voila!

$ bundle exec rake -T

#=> rake iron_hide:load_rules[file,db_server]  # Load rules from local JSON

Now read this

Self Hosted Gem Server with Jenkins and S3

On my team, we like to be able to keep our applications light. We use several internal libraries to manage things like distributed request tracing, authorization, configuration management, etc. Isolating this reusable, generic code into... Continue →