Class: KernelMappings

Inherits:
Object
  • Object
show all
Defined in:
lib/ec2/amitools/mapids.rb

Defined Under Namespace

Classes: MappingError

Constant Summary collapse

ENDPOINT = 
"http://ec2.amazonaws.com"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(akid, secretkey, source_images, target_region, endpoint = nil) ⇒ KernelMappings

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# File 'lib/ec2/amitools/mapids.rb', line 105

def initialize(akid, secretkey, source_images, target_region, endpoint=nil)
  @target_region = target_region
  @source_images = source_images
  create_ec2_connections(akid, secretkey, endpoint)
  unless @ec2conn.has_key?(target_region)
    raise MappingError.new("Invalid region: #{target_region}")
  end
end

Instance Attribute Details

#source_image_info ⇒ Object (readonly)

Returns the value of attribute source_image_info.



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# File 'lib/ec2/amitools/mapids.rb', line 18

def source_image_info
  @source_image_info
end

#target_image_info ⇒ Object (readonly)

Returns the value of attribute target_image_info.



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# File 'lib/ec2/amitools/mapids.rb', line 19

def target_image_info
  @target_image_info
end

Instance Method Details

#[](identifier) ⇒ Object

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Raises:



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# File 'lib/ec2/amitools/mapids.rb', line 136

def [](identifier)
  if @target_images_info.nil?
    get_source_images_info()
    get_target_candidates()
  end
  source_info = @source_images_info.find { |ii| ii['imageId'] == identifier }
  raise MappingError.new("'#{identifier}' not found.") if source_info.nil?
  source_match = matchable_image(source_info)
  target_info = @target_images_info.find { |ii| source_match == matchable_image(ii) }
  raise MappingError.new("Mapping for '#{identifier}' not found.") if target_info.nil?
  target_info['imageId']
end

#add_endpoint_from_env(endpoints) ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 29

def add_endpoint_from_env(endpoints)
  str = ENV['AMITOOLS_EC2_REGION_ENDPOINT']
  if not str
    return
  end

  components = str.split('@').collect{|s| s.strip()}
  if components.size != 2
    return
  end
  
  endpoints[components[0]] = components[1]
end

#create_ec2_connections(akid, secretkey, endpoint = nil) ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 60

def create_ec2_connections(akid, secretkey, endpoint=nil)
  @ec2conn = {}
  @endpoints = get_endpoints(akid, secretkey, endpoint)
  @endpoints.each do |region, endpoint|
    @ec2conn[region] = get_ec2_client(akid, secretkey, endpoint)
  end
end

#find_missing_targets(targets) ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 125

def find_missing_targets(targets)
  @target_images_info.each { |ii| targets.delete(ii['imageId']) } unless @target_images_info.nil?
  return nil if targets.empty?
  lookups = parse_imageset(@ec2conn[@target_region].describe_images(targets))
  lookups.each { |ii| targets.delete(ii['imageId']) }
  return nil if targets.empty?
  targets
end

#get_ec2_client(akid, secretkey, endpoint = nil) ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 23

def get_ec2_client(akid, secretkey, endpoint=nil)
  EC2::EC2Client.new(akid, secretkey, endpoint)
end

#get_endpoints(akid, secretkey, endpoint = nil) ⇒ Object 



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# File 'lib/ec2/amitools/mapids.rb', line 43

def get_endpoints(akid, secretkey, endpoint=nil)
  endpoint ||= ENDPOINT
  endpoints = {}
  ec2conn = get_ec2_client(akid, secretkey, endpoint)
  resp_doc = ec2conn.describe_regions()
  REXML::XPath.each(resp_doc.root, '/DescribeRegionsResponse/regionInfo/item') do |region|
    region_name = REXML::XPath.first(region, 'regionName').text
    region_url = REXML::XPath.first(region, 'regionEndpoint').text
    region_url = 'https://'+region_url unless region_url =~ %r{^https?://}
    endpoints[region_name] = region_url
  end
  add_endpoint_from_env(endpoints)
  endpoints
end

#get_source_images_info ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 70

def get_source_images_info()
  @ec2conn.each do |region, connection|
    $stderr.puts "Getting source data from #{region} #{@source_images.inspect}..." if @verbose
    resp_doc = connection.describe_images(@source_images)
    @source_images_info = parse_imageset(resp_doc)
    $stderr.puts "Found #{@source_images_info.size} images in #{region}." if @verbose
    # We assume all the images we're trying to map are in the same region.
    return if @source_images_info.size > 0
  end
end

#get_target_candidates ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 83

def get_target_candidates()
  owners = @source_images_info.map { |ii| ii['imageOwnerId'] }
  $stderr.puts "Getting target data from #{region} #{owners.inspect}..." if @verbose
  resp_doc = @ec2conn[@target_region].describe_images([], :ownerIds => owners)
  @target_images_info = parse_imageset(resp_doc)
  $stderr.puts "Found #{@target_images_info.size} images in #{region}." if @verbose
end

#matchable_image(image) ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 116

def matchable_image(image)
  summary = {}
  ['imageOwnerId', 'imageType'].each { |key| summary[key] = image[key] }
  summary[:s3key] = image['imageLocation'].sub(%r{^/*[^/]+/},'')
  summary
end

#parse_imageset(resp_doc) ⇒ Object

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# File 'lib/ec2/amitools/mapids.rb', line 93

def parse_imageset(resp_doc)
  images_info = []
  resp_doc.each_element('DescribeImagesResponse/imagesSet/item') do |image|
    image_data = {}
    image.each_element() { |elem| image_data[elem.name] = elem.text }
    images_info << image_data
  end
  images_info
end