June 19, 2014

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Fog Gem Support for SoftLayer
Things just got easier for developers working with the SoftLayer API. Support for SoftLayer is introduced with the rele

Things just got easier for developers working with the SoftLayer API. Support for SoftLayer is introduced with the release of fog-softlayer, which is a provider gem for fog, the Ruby cloud services library.

Fog is an open source cloud services library implemented in Ruby.

Call it what you will, fog calls it what it is.

CCI, VM, Cloud Server, Elastic Cloud Compute Instance, EC2, Compute Instance. All of these terms mean the exact same thing! They’re all different ways of saying an instance of an operating system is running on virtualized hardware in a cloud. The name you use depends on which cloud provider you’re working with.

When you’re using fog gem’s production proven object models, there is one set of resource names shared among every provider. It doesn’t matter what the provider calls the resource. And it doesn’t matter if the API that has access to it is REST, SOAP, or uses XML or JSON, as a developer you have one interface to learn and use.

Within fog are different providers, each one represents a cloud provider with publicly accessible APIs. Through the release of fog-softlayer, SoftLayer is now available as a provider.

Each provider offers at least the three following services.

  • Compute – A service that supports actions to create/update/destroy one or more instances of a cloud server.
  • DNS – A service that allows you to create/update/destroy records in the Domain Name System.
  • Storage – A service that allows you to create/update/destroy directories and files in an object-storage service.

In turn, each service exposes a set of models associated with that service. Based on the capabilities of different providers, there is some variation in models associated with a given service.

  • Compute Models: Server, Image and Flavor
  • DNS Models: Zone and Record
  • Storage Models: Directory and File
Fog in Action

Let’s take a look at two examples. The first launches a server on OpenStack and the second on native SoftLayer.

require ‘fog/softlayer’

initialize an OpenStack provider object.

@openstack = Fog::Compute[:openstack] # assumes credentials are in ~/.fog config file

get smallest flavor ID and default image ID for OpenStack

flavor = @openstack.flavors.first.id # => “1” image = @openstack.images.first.id # => “0e09fbd6-43c5-448a-83e9-0d3d05f9747e”

launch a small server on OpenStack

openstack_server = @openstack.servers.create(:flavor_ref => flavor, :image_ref => image, :name => ‘test-server’)

initialize a SoftLayer provider object.

@softlayer = Fog::Compute[:softlayer] # assumes credentials are in ~/.fog config file

get smallest flavor ID and default image ID for SoftLayer

flavor = @softlayer.flavors.first.id # => “m1.tiny” image = @softlayer.images.first.id #=> “3b235124-a190-40b5-9720-c020e61b99e1”

launch a small server on OpenStack

softlayer_server = @softlayer.servers.create(:flavor_id => flavor, :image_id => image, :name => ‘test-server’)

That’s about as painless as we can ask for. Most of the code is actually the same.

Let’s get even those lingering differences out of the way.

require ‘fog/softlayer’

class SmallServer attr_accessor :name attr_reader :flavor, :image def initialize(provider) @provider = provider @connection = Fog::Compute[provider] self.launch end

def launch begin @connection.servers.create(options) end end

def flavor @connection.flavors.first.id end

def image @connection.images.first.id end

def name @name ||= ‘test’ end

def options _flavor = openstack? ? :flavor_ref : :flavor_id _image = openstack? ? :image_ref : :image_id { _flavor => flavor, _image => image, :name => name} end

def openstack? @provider.match(/openstack/) end end

With that class available, let’s implement our example task of launching one server on each cloud.

require ‘fog/softlayer’ include SmallServer

launch a small server on OpenStack

openstack_server = SmallServer.new(:openstack)

launch a small server on SoftLayer

sl_server = SmallServer.new(:softlayer)

If we don’t count require and include, we’re down to two lines of code.

You can install fog-softlayer from rubygems.org via gem install fog-softlayer, or you can grab the source from github.com.

Alternatively, for something a little more lightweight, you can use the SoftLayer module as a stand-alone gem. Install that with gem install fog-softlayer or use the source.

\- Matt

– If you have questions about or problems with fog-softlayer open an issue or email me.


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