This is a MVP for the HTTP tap filter. It includes minimal
infrastructure for the following:
1. Generic tap configuration which in the future will be used for
static config, XDS config, etc. In this MVP the tap can be
configured via a /tap admin endpoint.
2. Generic output configuration which in the future will be used for
different output sinks such as files, gRPC API, etc. In this MVP
the tap results are streamed back out the /tap admin endpoint.
3. Matching infrastructure. In this MVP only matching on request and
response headers are implemented. Both logical AND and logical OR
matches are possible.
4. In this MVP request/response body is not considered at all.
5. All docs are included and with all the caveats the filter is ready
to use for the limited cases it supports (which are likely still to
be useful).
There is a lot of follow on work which I will do in subsequent PRs.
This includes:
1. Merging the existing capture transport socket into this framework.
2. Implementing body support, both for matching on body contents as
well as outputting body data.
3. Tap rate limiting so too many streams do not get tapped.
4. gRPC matching. Using reflection and loaded proto definitions, it will
be possible to match on gRPC fields.
5. JSON matching. If the body parses as JSON, we can allow matching on
JSON fields.
Part of https://github.com/envoyproxy/envoy/issues/1413.
Signed-off-by: Matt Klein <mklein@lyft.com>
Mirrored from https://github.com/envoyproxy/envoy @ cf80045587240d494e54e9772949bc9af5eda61f
data-plane-api(CircleCI)