Class: Stemcell::MetadataSource

Inherits:
Object
  • Object
show all
Includes:
Chef::Mixin::DeepMerge
Defined in:
lib/stemcell/metadata_source.rb,
lib/stemcell/metadata_source/configuration.rb,
lib/stemcell/metadata_source/chef_repository.rb

Defined Under Namespace

Classes: ChefRepository, Configuration

Constant Summary collapse

DEFAULT_CONFIG_FILENAME = 
'stemcell.json'
DEFAULT_BACKING_STORE = 
'instance_store'
DEFAULT_OPTIONS = 
{
  'chef_environment' => 'production',
  'git_branch'       => 'production',
  'count'            => 1,
  'instance_hostname' => '',
  'instance_domain_name' => '',
  'chef_package_source' => 'http://www.opscode.com/chef/download?p=${platform}&pv=${platform_version}&m=${arch}&v=${chef_version}&prerelease=false',
  'chef_version'      => '11.4.0',
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(chef_root, config_filename = DEFAULT_CONFIG_FILENAME) ⇒ MetadataSource

Returns a new instance of MetadataSource.



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# File 'lib/stemcell/metadata_source.rb', line 27

def initialize(chef_root, config_filename=DEFAULT_CONFIG_FILENAME)
  @chef_root = chef_root
  @config_filename = config_filename

  if chef_root.nil?
    raise ArgumentError, "You must specify a chef repository"
  end
  if config_filename.nil?
    raise ArgumentError, "You must specify a configuration file"
  end

  @config = Configuration.new(File.join(chef_root, config_filename))
  @chef_repo = ChefRepository.new(chef_root)
end

Instance Attribute Details

#chef_repo ⇒ Object (readonly)

Returns the value of attribute chef_repo.



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# File 'lib/stemcell/metadata_source.rb', line 12

def chef_repo
  @chef_repo
end

#chef_root ⇒ Object (readonly)

Returns the value of attribute chef_root.



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# File 'lib/stemcell/metadata_source.rb', line 8

def chef_root
  @chef_root
end

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/stemcell/metadata_source.rb', line 11

def config
  @config
end

#config_filename ⇒ Object (readonly)

Returns the value of attribute config_filename.



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# File 'lib/stemcell/metadata_source.rb', line 9

def config_filename
  @config_filename
end

Instance Method Details

#default_options ⇒ Object 



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# File 'lib/stemcell/metadata_source.rb', line 42

def default_options
  DEFAULT_OPTIONS.merge(config.default_options)
end

#expand_role(role, environment, contexts = [], override_options = {}, options = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/stemcell/metadata_source.rb', line 46

def expand_role(role, environment, contexts=[], override_options={}, options={})
  raise ArgumentError, "Missing chef role" unless role
  raise ArgumentError, "Missing chef environment" unless environment
  allow_empty_roles = options.fetch(:allow_empty_roles, false)

  # Normal and cookbook attributes to load during role metadata expansion
  normal_attributes     = options.fetch(:normal_attributes, {})
  cookbook_attributes   = override_options['chef_cookbook_attributes']
  cookbook_attributes ||= config.default_options['chef_cookbook_attributes']
  cookbook_attributes ||= []

  chef_options = {}
  chef_options[:cookbook_attributes] = cookbook_attributes unless cookbook_attributes.empty?
  chef_options[:normal_attributes] = normal_attributes unless normal_attributes.empty?

  # Step 1: Expand the role metadata
  role_options = chef_repo.metadata_for_role(role, environment, chef_options)
  role_empty   = role_options.nil? || role_options.empty?

  raise EmptyRoleError if !allow_empty_roles && role_empty

  # Step 1.5: Override context specific values
  if !role_empty
    context_overrides = role_options['context_overrides'] || {}
    contexts.each do |context|
      overriding_hash = context_overrides[context]
      role_options.merge!(overriding_hash) if overriding_hash
    end
    role_options.delete('context_overrides')
  end

  # Step 2: Determine the backing store from available options.

  # This is determined distinctly from the merge sequence below because
  # the backing store options must be available to the operation.

  backing_store   = override_options['backing_store']
  backing_store ||= role_options.to_hash['backing_store'] if role_options
  backing_store ||= config.default_options['backing_store']
  backing_store ||= DEFAULT_BACKING_STORE

  backing_store_region   = override_options['region']
  backing_store_region ||= role_options.to_hash['region'] if role_options
  backing_store_region ||= config.default_options['region']
  backing_store_region ||= DEFAULT_OPTIONS['region']

  # Step 3: Retrieve the backing store options from the defaults.

  backing_store_options = config.options_for_backing_store(backing_store, backing_store_region)
  backing_store_options['backing_store'] = backing_store

  # Step 4: Merge the options together in priority order.

  merged_options = DEFAULT_OPTIONS.dup
  merged_options.merge!(config.default_options)
  merged_options.merge!(backing_store_options)
  merged_options.merge!(role_options.to_hash) if role_options
  merged_options.merge!(override_options)

  # Step 5: If no availability zone was specified, select one at random.

  if merged_options['availability_zone'].nil? && merged_options['region']
    merged_options['availability_zone'] ||=
      config.random_az_for_region(merged_options['region'])
  end

  # Step 6: Mandate that the environment and role were as specified.

  merged_options['chef_environment'] = environment
  merged_options['chef_role'] = role

  merged_options
end