Class: Bosh::Agent::Infrastructure::Aws::Registry

Inherits:
Object
  • Object
show all
Defined in:
lib/bosh_agent/infrastructure/aws/registry.rb

Constant Summary collapse

API_TIMEOUT = 
86400 * 3
CONNECT_TIMEOUT = 
30
INSTANCE_DATA_URI = 
"http://169.254.169.254/latest"

Class Method Summary collapse

Class Method Details

.bosh_lookup(hostname, nameservers) ⇒ Object

Raises:

  • (Resolv::ResolvError) 


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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 124

def bosh_lookup(hostname, nameservers)
  resolver = Resolv.new([Resolv::Hosts.new, Resolv::DNS.new(nameserver: nameservers)])
  resolver.each_address(hostname) do |address|
    begin
      return address if IPAddr.new(address).ipv4?
    rescue ArgumentError
    end
  end
  raise Resolv::ResolvError, "Could not resolve #{hostname}"
end

.current_instance_id ⇒ Object

Reads current instance id from EC2 metadata. We are assuming instance id cannot change while current process is running and thus memoizing it.



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 40

def current_instance_id
  return @current_instance_id if @current_instance_id
  @current_instance_id = get_uri("/meta-data/instance-id/")
end

.extract_registry_hostname(endpoint) ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 135

def extract_registry_hostname(endpoint)
  uri = URI.parse(endpoint)
  hostname = uri.hostname

  if hostname.nil?
    raise LoadSettingsError, "Could not extract registry hostname"
  end

  hostname
end

.get_json_from_url(url) ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 45

def get_json_from_url(url)
  client = HTTPClient.new
  client.send_timeout = API_TIMEOUT
  client.receive_timeout = API_TIMEOUT
  client.connect_timeout = CONNECT_TIMEOUT

  headers = {"Accept" => "application/json"}
  response = client.get(url, {}, headers)

  if response.status != 200
    raise(LoadSettingsError,
          "Cannot read settings for `#{url}' from registry, " \
          "got HTTP #{response.status}")
  end

  body = Yajl::Parser.parse(response.body)
  unless body.is_a?(Hash)
    raise(LoadSettingsError,
          "Invalid response from #{url} , Hash expected, " \
          "got #{body.class}: #{body}")
  end

  body

rescue HTTPClient::BadResponseError => e
  raise(LoadSettingsError,
        "Received bad HTTP response from registry: #{e.inspect}")
rescue HTTPClient::TimeoutError
  raise(LoadSettingsError,
        "Timed out reading json from #{url}, " \
        "please make sure agent is running on EC2 instance")
rescue URI::Error, SocketError, Errno::ECONNREFUSED, SystemCallError => e
  raise(LoadSettingsError,
        "Error requesting registry information #{e.inspect}")
rescue Yajl::ParseError => e
  raise(LoadSettingsError,
        "Cannot parse settings for from registry #{e.inspect}")
end

.get_openssh_key ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 152

def get_openssh_key
  get_uri("/meta-data/public-keys/0/openssh-key")
end

.get_registry_endpoint ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 84

def get_registry_endpoint
  user_data = get_json_from_url(INSTANCE_DATA_URI + "/user-data")
  unless user_data.has_key?("registry") &&
         user_data["registry"].has_key?("endpoint")
    raise(LoadSettingsError,
          "Cannot parse user data for endpoint #{user_data.inspect}")
  end
  Bosh::Agent::Config.logger.info("got user_data: #{user_data}")
  lookup_registry(user_data)
end

.get_settings ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 156

def get_settings
  @registry_endpoint ||= get_registry_endpoint
  url = "#{@registry_endpoint}/instances/#{current_instance_id}/settings"
  body = get_json_from_url(url)

  settings = Yajl::Parser.parse(body["settings"])
  unless settings.is_a?(Hash)
    raise(LoadSettingsError, "Invalid settings format, " \
                "Hash expected, got #{settings.class}: " \
                "#{settings}")
  end

  settings

rescue Yajl::ParseError
  raise(LoadSettingsError,
        "Cannot parse settings from registry #{@registry_endpoint}")
end

.get_uri(uri) ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 11

def get_uri(uri)
  client = HTTPClient.new
  client.send_timeout = API_TIMEOUT
  client.receive_timeout = API_TIMEOUT
  client.connect_timeout = CONNECT_TIMEOUT

  response = client.get(INSTANCE_DATA_URI + uri)
  unless response.status == 200
    raise(LoadSettingsError, "Instance metadata endpoint returned " \
                             "HTTP #{response.status}")
  end

  response.body
rescue HTTPClient::BadResponseError => e
  raise(LoadSettingsError,
        "Received bad HTTP response for #{uri}: #{e.inspect}")
rescue HTTPClient::TimeoutError
  raise(LoadSettingsError,
        "Timed out reading uri #{uri}, " \
        "please make sure agent is running on EC2 instance")
rescue URI::Error, SocketError, Errno::ECONNREFUSED, SystemCallError => e
  raise(LoadSettingsError,
        "Error requesting current instance id from #{uri} #{e.inspect}")
end

.inject_registry_ip(ip, endpoint) ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 146

def inject_registry_ip(ip, endpoint)
  uri = URI.parse(endpoint)
  uri.hostname = ip
  uri.to_s
end

.lookup_registry(user_data) ⇒ Object

If the registry endpoint is specified with a bosh dns name, e.g. 0.registry.default.aws.bosh, then the agent needs to lookup the name and insert the IP address, as the agent doesn’t update resolv.conf until after the bootstrap is run.



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# File 'lib/bosh_agent/infrastructure/aws/registry.rb', line 99

def lookup_registry(user_data)
  endpoint = user_data["registry"]["endpoint"]

  # if we get data from an old director which doesn't set dns
  # info, there is noting we can do, so just return the endpoint
  if user_data["dns"].nil? || user_data["dns"]["nameserver"].nil?
    return endpoint
  end

  hostname = extract_registry_hostname(endpoint)

  # if the registry endpoint is an IP address, just return the endpoint
  unless (IPAddr.new(hostname) rescue(nil)).nil?
    return endpoint
  end

  nameservers = user_data["dns"]["nameserver"]
  ip = bosh_lookup(hostname, nameservers)
  inject_registry_ip(ip, endpoint)
rescue Resolv::ResolvError => e
  raise(LoadSettingsError,
        "Cannot lookup #{hostname} using #{nameservers.join(', ')}" +
            "\n#{e.inspect}")
end