Gem Version
gem install fog

fog is the Ruby cloud computing library, top to bottom:


A high level interface to each cloud is provided through collections, such as images and servers. You can see a list of available collections by calling collections on the connection object. You can try it out using the fog command:

>> AWS.collections
[:addresses, :directories, ..., :volumes, :zones]

Some collections are available across multiple providers:

Collections share basic CRUD type operations, such as:

As an example, we’ll try initializing and persisting a Rackspace Cloud server:

require 'fog'

compute ={
  :provider           => 'Rackspace',
  :rackspace_api_key  => key,
  :rackspace_username => username

# boot a gentoo server (flavor 1 = 256, image 3 = gentoo 2008.0)
server = compute.servers.create(:flavor_id => 1, :image_id => 3, :name => 'my_server')
server.wait_for { ready? } # give server time to boot


server.destroy # cleanup after yourself or regret it, trust me


Many of the collection methods return individual objects, which also provide common methods:


Requests allow you to dive deeper when the models just can’t cut it. You can see a list of available requests by calling #requests on the connection object.

For instance, ec2 provides methods related to reserved instances that don’t have any models (yet). Here is how you can lookup your reserved instances:

$ fog
>> AWS[:ec2].describe_reserved_instances
#<Excon::Response [...]>

It will return an excon response, which has body, headers and status. Both return nice hashes.


As you might imagine, testing code using Fog can be slow and expensive, constantly turning on and and shutting down instances. Mocking allows skipping this overhead by providing an in memory representation resources as you make requests. Enabling mocking easy to use, before you run other commands, simply run:


Then proceed as usual, if you run into unimplemented mocks fog will raise an error and as always contributions are welcome!