[DNM] test upgrade grpc/protobuf

[crazy-max]

Just testing grpc upgrade. ref moby/moby#42983 (comment)

cc @thaJeztah

Signed-off-by: CrazyMax crazy-max@users.noreply.github.com

[crazy-max]

# github.com/docker/swarmkit/vendor/github.com/coreos/etcd/clientv3/balancer/resolver/endpoint
vendor/github.com/coreos/etcd/clientv3/balancer/resolver/endpoint/endpoint.go:114:78: undefined: resolver.BuildOption
vendor/github.com/coreos/etcd/clientv3/balancer/resolver/endpoint/endpoint.go:182:31: undefined: resolver.ResolveNowOption
# github.com/docker/swarmkit/vendor/github.com/coreos/etcd/clientv3/balancer/picker
vendor/github.com/coreos/etcd/clientv3/balancer/picker/err.go:37:44: undefined: balancer.PickOptions
vendor/github.com/coreos/etcd/clientv3/balancer/picker/roundrobin_balanced.go:55:54: undefined: balancer.PickOptions

@dperny Upgrading gRPC on this repo will require some effort because we need to also update etcd >= 3.5 to match the new grpc resolver signature (>= 1.27.0).

We might also need to update to Go 1.16 min before that (cc @errordeveloper).

[errordeveloper]

We might also need to update to Go 1.16 min before that

Sure, let me try to do that!

[crazy-max]

We might also need to update to Go 1.16 min before that

Sure, let me try to do that!

We should match the one from moby I guess (1.17.3 atm). cc @thaJeztah

[crazy-max]

@errordeveloper Not tested but I have a branch I just push if you want to take a look: https://github.com/crazy-max/swarmkit/tree/go117

Edit: see also moby/moby#42778 (comment)

[thaJeztah]

We should match the one from moby I guess (1.17.3 atm). cc @thaJeztah

Yes, we should open a PR for that (can be separate from this one - hopefully will be an easy review/merge)