Provide additional gemspecs for various backends and a 'core' that they all depend on.

Gemfile

@@ -1,6 +1,6 @@
 # encoding: utf-8
 source 'https://rubygems.org'
-gemspec
+gemspec name: 'train'
 
 # pin dependency for Ruby 1.9.3 since bundler is not
 # detecting that net-ssh 3 does not work with 1.9.3

Rakefile

@@ -2,10 +2,12 @@
 # encoding: utf-8
 
 require 'bundler'
-require 'bundler/gem_tasks'
+require 'bundler/gem_helper'
 require 'rake/testtask'
 require 'rubocop/rake_task'
 
+Bundler::GemHelper.install_tasks name: 'train'
+
 # Rubocop
 desc 'Run Rubocop lint checks'
 task :rubocop do

train-aws.gemspec

@@ -0,0 +1,23 @@
+# encoding: utf-8
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'train/version'
+
+Gem::Specification.new do |spec|
+  spec.name          = 'train-aws'
+  spec.version       = Train::VERSION
+  spec.authors       = ['Dominik Richter']
+  spec.email         = ['dominik.richter@gmail.com']
+  spec.summary       = 'Provides AWS support to train-core.'
+  spec.description   = 'Provides AWS support to train-core.'
+  spec.homepage      = 'https://github.com/chef/train/'
+  spec.license       = 'Apache-2.0'
+
+  spec.files = %w{train-aws.gemspec README.md LICENSE Gemfile CHANGELOG.md
+                  lib/train/transports/aws.rb}
+
+  spec.require_paths = ['lib']
+
+  spec.add_dependency 'train-core'
+  spec.add_dependency 'aws-sdk', '~> 2'
+end

train-azure.gemspec

@@ -0,0 +1,23 @@
+# encoding: utf-8
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'train/version'
+
+Gem::Specification.new do |spec|
+  spec.name          = 'train-azure'
+  spec.version       = Train::VERSION
+  spec.authors       = ['Dominik Richter']
+  spec.email         = ['dominik.richter@gmail.com']
+  spec.summary       = 'Provides Azure support to train-core.'
+  spec.description   = 'Provides Azure support to train-core.'
+  spec.homepage      = 'https://github.com/chef/train/'
+  spec.license       = 'Apache-2.0'
+
+  spec.files = %w{train-azure.gemspec README.md LICENSE CHANGELOG.md
+                  lib/train/transports/azure.rb}
+
+  spec.require_paths = ['lib']
+
+  spec.add_dependency 'train-core'
+  spec.add_dependency 'azure_mgmt_resources', '~> 0.15'
+end

train-core.gemspec

@@ -0,0 +1,34 @@
+# encoding: utf-8
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'train/version'
+
+Gem::Specification.new do |spec|
+  spec.name          = 'train-core'
+  spec.version       = Train::VERSION
+  spec.authors       = ['Dominik Richter']
+  spec.email         = ['dominik.richter@gmail.com']
+  spec.summary       = 'Transport interface to talk to a selected set of backends.'
+  spec.description   = 'A minimal Train with a selected set of backends, ssh, winrm, and docker.'
+  spec.homepage      = 'https://github.com/chef/train/'
+  spec.license       = 'Apache-2.0'
+
+  spec.files = %w{train-core.gemspec README.md LICENSE Gemfile CHANGELOG.md} + Dir
+               .glob('{lib,test}/**/*', File::FNM_DOTMATCH)
+               .reject { |f| File.directory?(f) || f =~ /aws|azure|gcp/ }
+
+  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
+  spec.require_paths = ['lib']
+
+  spec.add_dependency 'json', '>= 1.8', '< 3.0'
+  # chef-client < 12.4.1 require mixlib-shellout-2.0.1
+  spec.add_dependency 'mixlib-shellout', '~> 2.0'
+  # net-ssh 3.x drops Ruby 1.9 support, so this constraint could be raised when
+  # 1.9 support is no longer needed here or for Inspec
+  spec.add_dependency 'net-ssh', '>= 2.9', '< 5.0'
+  spec.add_dependency 'net-scp', '~> 1.2'
+  spec.add_dependency 'winrm', '~> 2.0'
+  spec.add_dependency 'winrm-fs', '~> 1.0'
+  spec.add_dependency 'docker-api', '~> 1.26'
+  spec.add_dependency 'inifile'
+end

train-gcp.gemspec

@@ -0,0 +1,26 @@
+# encoding: utf-8
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'train/version'
+
+Gem::Specification.new do |spec|
+  spec.name          = 'train-gcp'
+  spec.version       = Train::VERSION
+  spec.authors       = ['Dominik Richter']
+  spec.email         = ['dominik.richter@gmail.com']
+  spec.summary       = 'Provides Google Cloud Provider support to train-core.'
+  spec.description   = 'Provides Google Cloud Provider support to train-core.'
+  spec.homepage      = 'https://github.com/chef/train/'
+  spec.license       = 'Apache-2.0'
+
+  spec.files = %w{train-gcp.gemspec README.md LICENSE CHANGELOG.md
+                  lib/train/transports/gcp.rb}
+
+  spec.require_paths = ['lib']
+
+  spec.add_dependency 'train-core'
+  spec.add_dependency 'google-api-client', '~> 0.19.8'
+  spec.add_dependency 'googleauth', '~> 0.6.2'
+  spec.add_dependency 'google-cloud', '~> 0.51.1'
+  spec.add_dependency 'google-protobuf', '= 3.5.1'
+end