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#
# Author:: Tim Dysinger (<tim@dysinger.net>)
# Author:: Benjamin Black (<bb@opscode.com>)
# Author:: Christopher Brown (<cb@opscode.com>)
# Copyright:: Copyright (c) 2009 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
require 'net/http'
require 'socket'
module Ohai
module Mixin
##
# This code parses the EC2 Instance Metadata API to provide details
# of the running instance.
#
# Earlier version of this code assumed a specific version of the
# metadata API was available. Unfortunately the API versions
# supported by a particular instance are determined at instance
# launch and are not extended over the life of the instance. As such
# the earlier code would fail depending on the age of the instance.
#
# The updated code probes the instance metadata endpoint for
# available versions, determines the most advanced version known to
# work and executes the metadata retrieval using that version.
#
# If no compatible version is found, an empty hash is returned.
#
module Ec2Metadata
EC2_METADATA_ADDR = "169.254.169.254" unless defined?(EC2_METADATA_ADDR)
EC2_SUPPORTED_VERSIONS = %w[ 1.0 2007-01-19 2007-03-01 2007-08-29 2007-10-10 2007-12-15
2008-02-01 2008-09-01 2009-04-04 2011-01-01 2011-05-01 2012-01-12 ]
EC2_ARRAY_VALUES = %w(security-groups)
EC2_ARRAY_DIR = %w(network/interfaces/macs)
EC2_JSON_DIR = %w(iam)
def can_metadata_connect?(addr, port, timeout=2)
t = Socket.new(Socket::Constants::AF_INET, Socket::Constants::SOCK_STREAM, 0)
saddr = Socket.pack_sockaddr_in(port, addr)
connected = false
begin
t.connect_nonblock(saddr)
rescue Errno::EINPROGRESS
r,w,e = IO::select(nil,[t],nil,timeout)
if !w.nil?
connected = true
else
begin
t.connect_nonblock(saddr)
rescue Errno::EISCONN
t.close
connected = true
rescue SystemCallError
end
end
rescue SystemCallError
end
Ohai::Log.debug("can_metadata_connect? == #{connected}")
connected
end
def best_api_version
response = http_client.get("/")
unless response.code == '200'
raise "Unable to determine EC2 metadata version (returned #{response.code} response)"
end
versions = response.body.split("\n")
until (versions.empty? || EC2_SUPPORTED_VERSIONS.include?(versions.last)) do
pv = versions.pop
Ohai::Log.debug("EC2 shows unsupported metadata version: #{pv}") unless pv == 'latest'
end
Ohai::Log.debug("EC2 metadata version: #{versions.last}")
if versions.empty?
raise "Unable to determine EC2 metadata version (no supported entries found)"
end
versions.last
end
def http_client
Net::HTTP.start(EC2_METADATA_ADDR).tap {|h| h.read_timeout = 600}
end
def metadata_get(id, api_version)
http_client.get("/#{api_version}/meta-data/#{id}")
end
def fetch_metadata(id='', api_version=nil)
api_version ||= best_api_version
return Hash.new if api_version.nil?
metadata = Hash.new
metadata_get(id, api_version).body.split("\n").each do |o|
key = expand_path("#{id}#{o}")
if key[-1..-1] != '/'
metadata[metadata_key(key)] =
if EC2_ARRAY_VALUES.include? key
metadata_get(key, api_version).body.split("\n")
else
metadata_get(key, api_version).body
end
elsif not key.eql?(id) and not key.eql?('/')
name = key[0..-2]
sym = metadata_key(name)
if EC2_ARRAY_DIR.include?(name)
metadata[sym] = fetch_dir_metadata(key, api_version)
elsif EC2_JSON_DIR.include?(name)
metadata[sym] = fetch_json_dir_metadata(key, api_version)
else
fetch_metadata(key, api_version).each{|k,v| metadata[k] = v}
end
end
end
metadata
end
def fetch_dir_metadata(id, api_version)
metadata = Hash.new
metadata_get(id, api_version).body.split("\n").each do |o|
key = expand_path(o)
if key[-1..-1] != '/'
metadata[metadata_key(key)] = metadata_get("#{id}#{key}", api_version).body
elsif not key.eql?('/')
metadata[key[0..-2]] = fetch_dir_metadata("#{id}#{key}", api_version)
end
end
metadata
end
def fetch_json_dir_metadata(id, api_version)
metadata = Hash.new
metadata_get(id, api_version).body.split("\n").each do |o|
key = expand_path(o)
if key[-1..-1] != '/'
data = metadata_get("#{id}#{key}", api_version).body
json = StringIO.new(data)
parser = Yajl::Parser.new
metadata[metadata_key(key)] = parser.parse(json)
elsif not key.eql?('/')
metadata[key[0..-2]] = fetch_json_dir_metadata("#{id}#{key}", api_version)
end
end
metadata
end
def fetch_userdata()
api_version = best_api_version
return nil if api_version.nil?
response = http_client.get("/#{api_version}/user-data/")
response.code == "200" ? response.body : nil
end
private
def expand_path(file_name)
path = file_name.gsub(/\=.*$/, '/')
# ignore "./" and "../"
path.gsub(%r{/\.\.?(?:/|$)}, '/').
sub(%r{^\.\.?(?:/|$)}, '').
sub(%r{^$}, '/')
end
def metadata_key(key)
key.gsub(/\-|\//, '_')
end
end
end
end
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