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 



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# File 'lib/fog/aws/credential_fetcher.rb', line 13

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]

      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

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

      session = Fog::JSON.decode(role_data)
      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
      #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 



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# File 'lib/fog/aws/credential_fetcher.rb', line 60

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