File: ec2.rb

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

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.

Required files

open-uri socket

Methods

can_metadata_connect? has_ec2_mac? looks_like_ec2? metadata userdata

Constants

 "169.254.169.254" unless defined?(EC2_METADATA_ADDR)
 "http://#{EC2_METADATA_ADDR}/2008-02-01/meta-data" unless defined?(EC2_METADATA_URL)
 "http://#{EC2_METADATA_ADDR}/2008-02-01/user-data" unless defined?(EC2_USERDATA_URL)

Public Instance methods

can_metadata_connect?(addr, port, timeout=2)

[Source]

    # File lib/ohai/plugins/ec2.rb, line 33
33: def can_metadata_connect?(addr, port, timeout=2)
34:   t = Socket.new(Socket::Constants::AF_INET, Socket::Constants::SOCK_STREAM, 0)
35:   saddr = Socket.pack_sockaddr_in(port, addr)
36:   connected = false
37: 
38:   begin
39:     t.connect_nonblock(saddr)    
40:   rescue Errno::EINPROGRESS
41:     r,w,e = IO::select(nil,[t],nil,timeout)
42:     if !w.nil?
43:       connected = true
44:     else
45:       begin
46:         t.connect_nonblock(saddr)
47:       rescue Errno::EISCONN
48:         t.close
49:         connected = true
50:       rescue SystemCallError
51:       end
52:     end
53:   rescue SystemCallError
54:   end
55: 
56:   connected
57: end

has_ec2_mac?()

[Source]

    # File lib/ohai/plugins/ec2.rb, line 59
59: def has_ec2_mac?
60:   network[:interfaces].values.each do |iface|
61:     unless iface[:arp].nil?
62:       return true if iface[:arp].value?("fe:ff:ff:ff:ff:ff")
63:     end
64:   end
65:   false
66: end

looks_like_ec2?()

[Source]

    # File lib/ohai/plugins/ec2.rb, line 89
89: def looks_like_ec2?
90:   # Try non-blocking connect so we don't "block" if 
91:   # the Xen environment is *not* EC2
92:   has_ec2_mac? && can_metadata_connect?(EC2_METADATA_ADDR,80)
93: end

metadata(id='')

[Source]

    # File lib/ohai/plugins/ec2.rb, line 68
68: def metadata(id='')
69:   OpenURI.open_uri("#{EC2_METADATA_URL}/#{id}").read.split("\n").each do |o|
70:     key = "#{id}#{o.gsub(/\=.*$/, '/')}"
71:     if key[-1..-1] != '/'
72:       ec2[key.gsub(/\-|\//, '_').to_sym] =
73:         OpenURI.open_uri("#{EC2_METADATA_URL}/#{key}").read
74:     else
75:       metadata(key)
76:     end
77:   end
78: end

userdata()

[Source]

    # File lib/ohai/plugins/ec2.rb, line 80
80: def userdata()
81:   ec2[:userdata] = nil
82:   # assumes the only expected error is the 404 if there's no user-data
83:   begin
84:     ec2[:userdata] = OpenURI.open_uri("#{EC2_USERDATA_URL}/").read
85:   rescue OpenURI::HTTPError
86:   end
87: end