Class: RightScale::CloudFactory

Inherits:
Object
  • Object
show all
Includes:
RightSupport::Ruby::EasySingleton
Defined in:
lib/clouds/cloud_factory.rb

Overview

Singleton for registering and instantiating clouds.

Defined Under Namespace

Classes: UnknownCloud

Constant Summary collapse

UNKNOWN_CLOUD_NAME =

the unknown cloud is used to automatically detect current instance’s cloud

:unknown

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.normalize_cloud_name(cloud_name) ⇒ Object

Normalizes a cloud name to ensure all variants are resolvable.

Parameters

cloud_name(String)

cloud name

Return

result(String)

normalized cloud name



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# File 'lib/clouds/cloud_factory.rb', line 165

def self.normalize_cloud_name(cloud_name)
  return cloud_name.to_s.strip.downcase
end

Instance Method Details

#create(cloud_name, options) ⇒ Object

Factory method for dynamic metadata types.

Parameters

cloud(String)

a registered_type cloud name

options(Hash)

options for creation

Return

result(Object)

new instance of registered_type metadata type

Raise

UnknownCloud

on error

Raises:

  • (ArgumentError) 


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# File 'lib/clouds/cloud_factory.rb', line 89

def create(cloud_name, options)
  raise ArgumentError.new("cloud_name is required") if cloud_name.to_s.empty?
  raise ArgumentError.new("options[:logger] is required") unless logger = options[:logger]
  raise UnknownCloud.new("No cloud definitions available.") unless @names_to_script_paths
  cloud_name = cloud_name.to_sym
  cloud_name = default_cloud_name if UNKNOWN_CLOUD_NAME == cloud_name
  if UNKNOWN_CLOUD_NAME == cloud_name
    # persist default cloud name after successful detection.
    cloud = detect_cloud(options)
    raise UnknownCloud.new("Unable to determine a default cloud") unless cloud
    default_cloud_name(cloud.name)
    return cloud
  end
  cloud_script_path = registered_script_path(cloud_name)
  options = options.dup
  options[:name] ||= cloud_name.to_s
  options[:script_path] = cloud_script_path
  cloud = Cloud.new(options)
  text = File.read(cloud_script_path)
  cloud.instance_eval(text)
  cloud.abbreviation(cloud_name) unless cloud.abbreviation
  extend_cloud_by_scripts(cloud, logger)

  # finalize defaults only after all cloud definitions have been evaluated
  # by the new cloud object.
  cloud.finalize_default_options
  return cloud
end

#default_cloud_name(value = nil) ⇒ Object

Setter/getter for the default cloud name. This currently relies on a ‘cloud file’ which must be present in an expected RightScale location.

Parameters

value(String|Token)

default cloud name or nil

Return

result(String)

default cloud name or nil



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# File 'lib/clouds/cloud_factory.rb', line 126

def default_cloud_name(value = nil)
  cloud_file_path = RightScale::AgentConfig.cloud_file_path
  if value
    parent_dir = File.dirname(cloud_file_path)
    FileUtils.mkdir_p(parent_dir) unless File.directory?(parent_dir)
    File.open(cloud_file_path, "w") { |f| f.write(value.to_s) }
  else
    value = File.read(cloud_file_path).strip if File.file?(cloud_file_path)
  end
  value.to_s.empty? ? UNKNOWN_CLOUD_NAME : value
end

#detect_cloud(options) ⇒ Object

Attempts to detect the current instance’s cloud by instantiating the various known clouds and running their detection methods.

Parameters

options(Hash)

options for creation or empty

Return

cloud(Cloud)

detected cloud or nil



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# File 'lib/clouds/cloud_factory.rb', line 146

def detect_cloud(options)
  @names_to_script_paths.each_key do |cloud_name|
    begin
      cloud = create(cloud_name, options)
      return cloud if cloud.is_current_cloud?
    rescue Exception
      # ignore failures and proceed to detecting next cloud, if any.
    end
  end
  nil
end

#register(cloud_names, cloud_script_path) ⇒ Object

Registry method for a dynamic metadata type.

Parameters

cloud_names(Array|String)

name of one or more clouds (which may include DEFAULT_CLOUD) that use the given type

cloud_script_path(String)

path to script used to describe cloud on creation

Return

always true



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# File 'lib/clouds/cloud_factory.rb', line 45

def register(cloud_names, cloud_script_path)
  # relies on each to split on newlines for strings and otherwise do each for collections.
  cloud_script_path = File.normalize_path(cloud_script_path)
  cloud_names.each { |cloud_name| registered_type(cloud_name, cloud_script_path) }
  true
end

#registered_script_path(cloud_name) ⇒ Object

Gets the path to the script describing a cloud.

Parameters

cloud_name(String)

a registered_type cloud name

Return

cloud_script_path(String)

path to script used to describe cloud on creation

Raise

UnknownCloud

on error

Raises:



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# File 'lib/clouds/cloud_factory.rb', line 72

def registered_script_path(cloud_name)
  cloud_script_path = registered_type(cloud_name)
  raise UnknownCloud.new("Unknown cloud: #{cloud_name}") unless cloud_script_path
  return cloud_script_path
end

#reset_registry ⇒ Object

Resets the global cloud registry (to ensure a clean reload of cloud names).

Return

result(Hash)

Hash of cloud names to script paths before reset



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# File 'lib/clouds/cloud_factory.rb', line 56

def reset_registry
  result = @names_to_script_paths
  @names_to_script_paths = nil
  result
end