# File lib/fog/aws/credential_fetcher.rb, line 12
        def fetch_credentials(options)
          if options[:use_iam_profile] && Fog.mocking?
            return Fog::Compute::AWS::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

                connection = options[:metadata_connection] || Excon.new(INSTANCE_METADATA_HOST)
                region ||= connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200).body[0..-2]
              else
                connection = options[:connection] || Excon.new(INSTANCE_METADATA_HOST)
                role_name = connection.get(:path => INSTANCE_METADATA_PATH, :idempotent => true, :expects => 200).body
                role_data = connection.get(:path => INSTANCE_METADATA_PATH+role_name, :idempotent => true, :expects => 200).body
                region ||= connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200).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