protoc-gen-loggingtags

protoc-gen-loggingtags

A protoc plugin that generates LoggingTags() map[string]interface{} methods on Go proto message structs based on field options inside the source .proto files. The logging tags returned are safe to log without leaking information. The logging tag methods are code-generated so it's always in sync with the source files.

The grpcserver package automatically checks if request or response messages implement the LoggingTags method and includes the returned tags in the context tags for logging.

Example

syntax = "proto3";
import "github.com/heroku/x/loggingtags/safe.proto";

package loggingtags.examples;

message Sample {
  string safe   = 1 [(heroku.loggingtags.safe) = true];
  string unsafe = 2;
}

When LoggingTags() is called on the Sample message, it will only include the name and value of the safe field.

The field values are unmodified, except for protobuf Timestamp and Duration fields, which are unpacked to return the native Go type.

Assuming protoc-gen-loggingtags and protoc-gen-go are installed into your path, code can be generated for the above proto definition with:

protoc \
  --proto_path=$GOPATH/src \
  --proto_path=. \
  --go_out=. \
  --loggingtags_out=. \
  sample.proto

If protoc-gen-loggingtags is vendored, the first proto_path directive should instead refer to the vendor's src directory.

Development

The internal/test package contains sample protobuf messages with loggingtag annotations and a test suite to exercise them.

Run make proto from the root to regenerate the loggingtags code for the sample messages using the current local version of the generator.