proto: Port *.proto to proto3

[wking]

Define syntax to fix:

protoc --go_out=./go config.proto
[libprotobuf WARNING google/protobuf/compiler/parser.cc:492] No
  syntax specified for the proto file. Please use 'syntax =
  "proto2";' or 'syntax = "proto3";' to specify a syntax
  version. (Defaulted to proto2 syntax.)

Drop optional (with sed -i 's/\toptional /\t/' *.proto) to fix:

protoc --go_out=./go config.proto
config.proto:9:18: Explicit 'optional' labels are disallowed in the
  Proto3 syntax. To define 'optional' fields in Proto3, simply
  remove the 'optional' label, as fields are 'optional' by default.

Replace the User extensions with Any (see also,
protocolbuffers/protobuf#828) to fix:

protoc --go_out=./go config.proto
config.proto: Extensions in proto3 are only allowed for defining
  options.

Drop required (with sed -i 's/\trequired /\t/' *.proto) to fix:

protoc --go_out=./go runtime_config.proto
runtime_config.proto: Required fields are not allowed in proto3.

Drop DefaultState to fix:

protoc --go_out=./go runtime_config.proto
runtime_config.proto: Explicit default values are not allowed in
  proto3.

There's still some trouble with the resulting Go:

go run ./example.go
go/config.pb.go:26:8: cannot find package "google/protobuf" in any of:
        /usr/lib/go/src/google/protobuf (from $GOROOT)
        /home/wking/.local/lib/go/src/google/protobuf (from $GOPATH)
Makefile:31: recipe for target 'example' failed

But I haven't been able to figure that out yet.

[wking]

I've added 8bead0f avoiding Any for now, and have ported example.go in a4d502c. Output now looks like:

{
  "spec": {
    "version": "",
    "platform": {
      "os": "linux",
      "arch": "x86_64"
    },
    "process": {
      "terminal": false,
      "env": [
        "TERM=linux"
      ],
      "cwd": "/"
    },
    "hostname": ""
  }
}

[wking]

I've figured out the ‘cannot find package "google/protobuf"’ error, and pushed da7a33f, which gives output like:

{
  "spec": {
    "version": "",
    "platform": {
      "os": "linux",
      "arch": "x86_64"
    },
    "process": {
      "terminal": false,
      "user": {
        "type_url": "oci.LinuxUser",
        "value": "qAYBsAYBuAYFuAYG"
      },
      "env": [
        "TERM=linux"
      ],
      "cwd": "/"
    },
    "hostname": ""
  }
}

It looks like golang/protobuf/jsonpb needs some more work to give us the expected:

  "user": {
    "@type": "type.googleapis.com/oci.LinuxUser",
    "uid": 1,
    "gid": 1,
    "additionalGids": [
      5,
      6
    ]
  },

we see with the C++ example in #3.

[wking]

As an alternative to my Dockerfile changes in da7a33f, we could also use go.pedge.io/google-protobuf (see golang/protobuf#50). I don't care either way.

[bufdev]

@wking Note I'm trying to push to get go.pedge.io/google-protobuf just merged into golang/protobuf, I also have go.pedge.io/googleapis now, it's no fun to maintain, but I promise neither will go anywhere (and the go.pedge.io server is dead simple).

Of note, I also have https://github.com/peter-edge/go-tools/tree/master/protoc-all (go get go.pedge.io/tools/protoc-all), which I'm happy to walk anyone through, I'm going to rewrite it soon as it's become a bit of a mess but it takes care of all the import paths (and uses go.pedge.io/google-protobuf).

[bufdev]

I'm not sure if google is moving away from this, but the general protobuf standard has been to not use plural names for repeated fields, so this would be mount or mount_point.

[bufdev]

Just made a few comments with some thoughts/suggestions, no worries but hoping they may be helpful :)

[wking]

On Sat, Oct 24, 2015 at 10:44:59AM -0700, Peter Edge wrote:

Just made a few comments with some thoughts/suggestions, no worries
but hoping they may be helpful :)

They sound reasonable to me, but I'm trying to keep this branch as
minimal as possible (just get proto3+Go working as well as possible,
and see how far that gets us). I'll leave the more peripheral
cleanups and idiomization to @vbatts and company if/when they decide
to actually go this route.

[vbatts]

This is obsolete now. 😅