[BUG] Warning about old library: github.com/golang/protobuf/protoc-gen-go/generator

[iranzo]

What happened:

$ microshift status

WARNING: Package "github.com/golang/protobuf/protoc-gen-go/generator" is deprecated.
        A future release of golang/protobuf will delete this package,
        which has long been excluded from the compatibility promise.

What you expected to happen:

No warnings output

How to reproduce it (as minimally and precisely as possible):

1. Run microshift with any command

Anything else we need to know?:

Environment:

Microshift Version: 4.7.0-0.microshift-unknown
Base OKD Version: 4.7.0-0.okd-2021-08-22-163618

Installed via curl

Running on RHEL 8.4

Relevant Logs

[fzdarsky]

The root cause seems to be that K8s 1.21 depends on github.com/golang/protobuf v1.5.0 (which deprecates the generator), but also on etcd v3.4.13, which uses the protoc-gen-go still. As we compile both into a single binary, the generator'sinit() function (https://github.com/golang/protobuf/blob/v1.5.0/protoc-gen-go/generator/generator.go#L42-L47) gets called.

I'm not sure how we can avoid this, other than patching out the init() function with the warning.

[fzdarsky]

More specifically, it's the vendored github.com/grpc-ecosystem/grpc-gateway at v1.9.5 (required by etcd) that pulls in the generator:
https://github.com/grpc-ecosystem/grpc-gateway/blob/v1.9.5/runtime/fieldmask.go#L8

This is "fixed" only in v1.11.3 of the grpc-gateway. Wondering whether bumping that dep is safe and solves the issue.