* cel: fix validation of expression result type
The earlier code used the proto.Equals from github.com/gogo/protobuf, which failed to compare two messages of the same type for some reason. Switching to proto.Equal from the canonical github.com/golang/protobuf fixes the issue.
* deps: remove deprecated github.com/golang/protobuf in favor of google.golang.org/protobuf
* downgrade github.com/smallstep/nosql to resolve warning pb.proto warning
* docs: link to CEL standard definitions
* Rephrase the anchor to CEL standard definitions
Co-authored-by: Matt Holt <mholt@users.noreply.github.com>
Co-authored-by: Matt Holt <mholt@users.noreply.github.com>
* caddyhttp: Implement CEL matcher (see #3051)
CEL (Common Expression Language) is a very fast, flexible way to express
complex logic, useful for matching requests when the conditions are not
easy to express with JSON.
This matcher may be considered experimental even after the 2.0 release.
* Improve CEL module docs