# File lib/deltacloud/drivers/ec2/ec2_driver.rb, line 633
        def firewalls(credentials, opts={})
          ec2 = new_client(credentials)
          the_firewalls = []
          groups = []
          safely do
            if opts[:id]
              groups = ec2.describe_security_groups([opts[:id]])
            else
              groups = ec2.describe_security_groups()
            end
          end
          groups.each do |security_group|
            the_firewalls << convert_security_group(security_group)
          end
          the_firewalls
        end