Module: Fog::AWS::CredentialFetcher::ServiceMethods

Included in:
AutoScaling, Fog::AWS::CDN, Fog::AWS::CloudFormation, Fog::AWS::CloudWatch, Fog::AWS::Compute, DNS, DataPipeline, DynamoDB, EFS, ELB, EMR, ElasticBeanstalk, Elasticache, Federation, Glacier, IAM, KMS, Kinesis, Lambda, RDS, Redshift, SES, SNS, SQS, STS, SimpleDB, Storage, Support
Defined in:
lib/fog/aws/credential_fetcher.rb

Instance Method Summary collapse

Instance Method Details

#fetch_credentials(options) ⇒ Object 



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
 
# File 'lib/fog/aws/credential_fetcher.rb', line 17

def fetch_credentials(options)
  if options[:use_iam_profile] && Fog.mocking?
    return Fog::AWS::Compute::Mock.data[:iam_role_based_creds]
  end
  if options[:use_iam_profile]
    begin
      role_data = nil
      region = options[:region] || ENV["AWS_REGION"] || ENV["AWS_DEFAULT_REGION"]

      if ENV["AWS_CONTAINER_CREDENTIALS_RELATIVE_URI"]
        connection = options[:connection] || Excon.new(CONTAINER_CREDENTIALS_HOST)
        credential_path = options[:credential_path] || ENV["AWS_CONTAINER_CREDENTIALS_RELATIVE_URI"]
        role_data = connection.get(:path => credential_path, :idempotent => true, :expects => 200).body
        session = Fog::JSON.decode(role_data)

        if region.nil?
          connection = options[:metadata_connection] || Excon.new(INSTANCE_METADATA_HOST)
          token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
          region = connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
        end
      elsif ENV["AWS_CONTAINER_CREDENTIALS_FULL_URI"]
        connection = options[:connection] || Excon.new(ENV['AWS_CONTAINER_CREDENTIALS_FULL_URI'])
        container_authorization_token = File.read(options[:aws_container_authorization_token_file] || ENV['AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE'])
        role_data = connection.get(:idempotent => true, :expects => 200, :headers => {'Authorization' => container_authorization_token}).body
        session = Fog::JSON.decode(role_data)

        if region.nil?
          connection = options[:metadata_connection] || Excon.new(INSTANCE_METADATA_HOST)
          token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
          region = connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
        end
      elsif ENV["AWS_WEB_IDENTITY_TOKEN_FILE"]
        params = {
          :Action => "AssumeRoleWithWebIdentity",
          :RoleArn => options[:role_arn] || ENV.fetch("AWS_ROLE_ARN"),
          :RoleSessionName => options[:role_session_name] || ENV["AWS_ROLE_SESSION_NAME"] || "fog-aws-#{SecureRandom.hex}",
          :WebIdentityToken => File.read(options[:aws_web_identity_token_file] || ENV.fetch("AWS_WEB_IDENTITY_TOKEN_FILE")),
          :DurationSeconds => options[:duration] || 3600,
          :Version => "2011-06-15",
        }

        sts_endpoint =
          if ENV["AWS_ENDPOINT_URL_STS"]
            ENV["AWS_ENDPOINT_URL_STS"]
          elsif ENV["AWS_STS_REGIONAL_ENDPOINTS"] == "regional" && region
            "https://sts.#{region}.amazonaws.com"
          else
            "https://sts.amazonaws.com"
          end

        connection = options[:connection] || Excon.new(sts_endpoint, :query => params)
        document = Nokogiri::XML(connection.get(:idempotent => true, :expects => 200).body)

        session = {
          "AccessKeyId" => document.css("AccessKeyId").children.text,
          "SecretAccessKey" => document.css("SecretAccessKey").children.text,
          "Token" => document.css("SessionToken").children.text,
          "Expiration" => document.css("Expiration").children.text,
        }

        if region.nil?
          connection = options[:metadata_connection] || Excon.new(INSTANCE_METADATA_HOST)
          token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
          region = connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
        end
      else
        connection = options[:connection] || Excon.new(INSTANCE_METADATA_HOST)
        token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
        role_name = connection.get(:path => INSTANCE_METADATA_PATH, :idempotent => true, :expects => 200, :headers => token_header).body
        role_data = connection.get(:path => INSTANCE_METADATA_PATH+role_name, :idempotent => true, :expects => 200, :headers => token_header).body
        session = Fog::JSON.decode(role_data)

        region ||= connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
      end

      credentials = {}
      credentials[:aws_access_key_id] = session['AccessKeyId']
      credentials[:aws_secret_access_key] = session['SecretAccessKey']
      credentials[:aws_session_token] = session['Token']
      credentials[:aws_credentials_expire_at] = Time.xmlschema session['Expiration']

      # set region by default to the one the instance is in.
      credentials[:region] = region
      credentials[:sts_endpoint] = sts_endpoint if sts_endpoint
      #these indicate the metadata service is unavailable or has no profile setup
      credentials
    rescue Excon::Error => e
      Fog::Logger.warning("Unable to fetch credentials: #{e.message}")
      super
    end
  else
    super
  end
end

#fetch_credentials_token_header(connection, disable_imds_v2) ⇒ Object 



112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
 
# File 'lib/fog/aws/credential_fetcher.rb', line 112

def fetch_credentials_token_header(connection, disable_imds_v2)
  return nil if disable_imds_v2

  token = connection.put(
    :path => INSTANCE_METADATA_TOKEN,
    :idempotent => true,
    :expects => 200,
    :retry_interval => 1,
    :retry_limit => 3,
    :read_timeout => 1,
    :write_timeout => 1,
    :connect_timeout => 1,
    :headers => { "X-aws-ec2-metadata-token-ttl-seconds" => "300" }
  ).body

  { "X-aws-ec2-metadata-token" => token }
rescue Excon::Error
  nil
end