Class: EC2APIProxy::Proxy

Inherits:
EM::Connection
  • Object
show all
Defined in:
lib/ec2-api-proxy/proxy.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options, memcached) ⇒ Proxy

Returns a new instance of Proxy.



13
14
15
16
17
18
19
 
# File 'lib/ec2-api-proxy/proxy.rb', line 13

def initialize(options, memcached)
  @options = options
  @memcached = memcached
  @logger = Logger.new($stdout)
  @data_len = nil
  @data = ''
end

Instance Attribute Details

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



10
11
12
 
# File 'lib/ec2-api-proxy/proxy.rb', line 10

def logger
  @logger
end

#memcached ⇒ Object (readonly)

Returns the value of attribute memcached.



11
12
13
 
# File 'lib/ec2-api-proxy/proxy.rb', line 11

def memcached
  @memcached
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



9
10
11
 
# File 'lib/ec2-api-proxy/proxy.rb', line 9

def options
  @options
end

Instance Method Details

#post_init ⇒ Object 



21
22
23
24
25
26
27
28
29
30
 
# File 'lib/ec2-api-proxy/proxy.rb', line 21

def post_init
  if (peername = get_peername)
    @connect_from = Socket.unpack_sockaddr_in(peername)
  end

  if @options[:debug]
    port, ip = @connect_from
    @logger.debug("proxy: connect from #{ip}:#{port}")
  end
end

#receive_data(data) ⇒ Object 



41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
 
# File 'lib/ec2-api-proxy/proxy.rb', line 41

def receive_data(data)
  @data << data

  unless @data_len
    content_length = data.split("\r\n").find {|i| /\AContent-Length:/i =~ i }
    @data_len = content_length ? content_length.split(/:\s+/, 2).last.to_i : 0
  end

  content = @data.split("\r\n\r\n", 2).last || ''
  @logger.debug("proxy: receive data (length=#{@data_len}, receive=#{content.length})") if @options[:debug]
  return if content.length < @data_len

  EM.defer {
    begin
      endpoint, params = parse_proxy_request(@data)
      action = (params['Action'] || []).first
      allow_cache = !!(/\ADescribe/ =~ action)
      key = params_to_key(params)

      @logger.debug("proxy: #{action} (allow_cache=#{allow_cache})") if @options[:debug]

      if (allow_cache and cache = @memcached.get(key))
        @logger.debug("proxy: cache hit (length=#{cache.length})") if @options[:debug]
        send_data(cache)
        close_connection_after_writing
      else
        @logger.debug("proxy: cache miss") if @options[:debug]
        @backend = EM.connect(
                     endpoint.host,
                     @options[:use_https] ? 443 : endpoint.port,
                     EC2APIProxy::Backend,
                     self,
                     allow_cache ? key : nil
                   )

        if @backend.error?
          @logger.error("proxy: backend connection error: #{@data.inspect}")
          send_error('ec2-api-proxy-backend-connection-error', 'backend connection error')
          close_backend_connection
          close_connection_after_writing
        else
          @backend.send_data(@data)
        end
      end
    rescue => e
      @logger.error("#{e.class.name}: #{e.message}\n\tfrom #{e.backtrace.join("\n\tfrom ")}")
      send_error(e.class.name, e.message)
      close_backend_connection
      close_connection_after_writing
    end
  }
end

#unbind ⇒ Object 



32
33
34
35
36
37
38
39
 
# File 'lib/ec2-api-proxy/proxy.rb', line 32

def unbind
  close_backend_connection

  if @options[:debug]
    port, ip = @connect_from
    @logger.debug("proxy: unbind connection from #{ip}:#{port}")
  end
end