I had been trying to figure out a good way to provide more internally-derived feedback from an *ext_proc* implementation to *envoy* (without needing to do things like set response headers or rely on a separate log file), and was led to the discovery that the `ImmediateResponse.Details` field actually populates `%RESPONSE_CODE_DETAILS%` for use in access logging.
Due to how much better this discovery made my life, I am hoping it will make other people's lives better as well.
Signed-off-by: Chet Nichols III <chet@apple.com>
Mirrored from https://github.com/envoyproxy/envoy @ e00aa66429181e3973cc69ca57c26da730cc47af