Context and Terminology ======================= Traffic Server implements automated end to end testing via autest. These tests make use of a variety of tools to exercise traffic that verifies proper Traffic Server behavior. Curl, microserver, and tcp_client.py are examples of such tools. Further, to make the use of these tools more convenient, the Traffic Server autest suite contains autest extensions for some of these tools. The extensions are found in tests/gold_tests/autest-site.
Challenges ========== Currently, none of these test tools provide a convenient mechanism for crafting arbitrary HTTP traffic across specified sessions and connections. Curl is a handy HTTP client for creating single, simple HTTP transactions in a single connection, but it doesn't support multiple transactions in a single connection. Further, the crafting of more than a single header on the command line in Python with Curl, and then configuring microserver to respond to those requests as expected, becomes unwieldy in the autest files. Proposal ======== Proxy Verifier is a test tool designed to conveniently replay HTTP traffic and verify proxy behavior: https://github.com/yahoo/proxy-verifier Proxy Verifier delivers a verifier-client and verifier-server that function as an HTTP client and server which talk through a proxy, the entity under test. The HTTP traffic to replay and verification directives are described via a set of one or more YAML files. Here's an example replay file describing two transactions: https://github.com/yahoo/proxy-verifier/blob/76db9d9856c72782cc8f4ddef9cdaeb25de86f58/test/autests/gold_tests/field_parsing/replay_files/transaction_fields/transaction_fields.yaml This proposal suggests we update Traffic Server's autest suite to support the use of Proxy Verifier as a tool for use by the tests. Analogous to the MakeOriginServer microserver extension, convenience autest extensions will be created to start and configure the Proxy Verifier client and server processes: * MakeVerifierClientProcess * MakeVerifierServerProcess These will expose an API to configure the client and the server concerning such things as which ports to use and the location of the YAML files describing the replay traffic. Expectations concerning Traffic Server's behavior will also be described in the YAML replay files, and the extensions will set expectations to verify that these validation criteria are not violated. Initially, the user will build the Proxy Verifier binaries separately from Traffic Server. The location of these binaries will be provided via a --verifier-bin command line argument, similar to the --ats-bin command line argument currently provided. Tests that use Proxy Verifier can be configured conditional upon the presence of these binaries, just as certain tests are conditional upon the presence of Curl. In the future, we can consider updating the Verifier autest extensions to grab the Proxy Verifier source and build it locally if that is deemed helpful by the community. As a result of these efforts, we will have in Proxy Verifier a more convenient and natural mechanism for describing HTTP test traffic in our autests along with an expressive way to verify Traffic Server's proxying of this traffic. Please share any suggestions or concerns. Thanks, Brian -- "Come to Me, all who are weary and heavy-laden, and I will give you rest. Take My yoke upon you and learn from Me, for I am gentle and humble in heart, and you will find rest for your souls. For My yoke is easy and My burden is light." ~ Matthew 11:28-30
