connectrpc: generate code with buf

Generate the additional code required for connectrpc with the buf
tool. Currently, there is no bazel ruleset available for buf. We work
around this by invoking the buf binary directly and commiting the
generated code in git. To deal with generation, we pin the
`protoc-gen-connect-go` version in the go.mod file. A small scaffolding
go binary is added to deal with setting up the environment correctly
for the buf tool. While this could be a shell script, this is more
readable and maintainable.

This PR is broken out of the
https://github.com/scionproto/scion/tree/connectrpc branch to make
incremental review easier.

TL;DR: Run `bazel run //tools/buf` to generate the connectrpc code.

BUILD.bazel

@@ -1,5 +1,4 @@
-load("@bazel_skylib//rules:common_settings.bzl", "bool_flag")
-load("@bazel_skylib//rules:common_settings.bzl", "string_flag")
+load("@bazel_skylib//rules:common_settings.bzl", "bool_flag", "string_flag")
 load("@bazel_gazelle//:def.bzl", "gazelle")
 load("@rules_pkg//:pkg.bzl", "pkg_tar")
 load("@io_bazel_rules_go//go:def.bzl", "nogo")
@@ -140,9 +139,10 @@ gazelle(
 go_lint_config(
     name = "go_lint_config",
     exclude_filter = [
-        "mock_",
-        ".pb.go",
+        ".connect.go",
         ".gen.go",
+        ".pb.go",
+        "mock_",
     ],
     visibility = [
         "//visibility:public",

Makefile

@@ -81,6 +81,8 @@ protobuf:
 	cp -r bazel-bin/pkg/proto/*/*/go_default_library_/github.com/scionproto/scion/pkg/proto/* pkg/proto
 	chmod 0644 pkg/proto/*/*.pb.go
 
+	bazel run //tools/buf
+
 mocks:
 	tools/gomocks.py
 
@@ -141,7 +143,7 @@ lint-protobuf: lint-protobuf-buf
 
 lint-protobuf-buf:
 	$(info ==> $@)
-	@tools/quiet bazel run --config=quiet @buf_bin//file:buf -- check lint
+	@tools/quiet bazel run --config=quiet @buf//:buf -- lint $(PWD) --path $(PWD)/proto
 
 lint-openapi: lint-openapi-spectral
 

WORKSPACE

@@ -2,7 +2,7 @@ workspace(
     name = "com_github_scionproto_scion",
 )
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive", "http_file")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 # linter rules
 http_archive(
@@ -205,6 +205,11 @@ load("@tester_debian10_packages//:packages.bzl", tester_debian_packages_install_
 
 tester_debian_packages_install_deps()
 
+# Buf CLI to generate connect-go
+load("//tools/buf:deps.bzl", "buf_dependencies")
+
+buf_dependencies()
+
 # protobuf/gRPC
 http_archive(
     name = "rules_proto_grpc",
@@ -237,16 +242,6 @@ http_archive(
     ],
 )
 
-http_file(
-    name = "buf_bin",
-    downloaded_file_path = "buf",
-    executable = True,
-    sha256 = "5faf15ed0a3cd4bd0919ba5fcb95334c1fd2ba32770df289d615138fa188d36a",
-    urls = [
-        "https://github.com/bufbuild/buf/releases/download/v0.20.5/buf-Linux-x86_64",
-    ],
-)
-
 load("//tools/lint/python:deps.bzl", "python_lint_deps")
 
 python_lint_deps(python_interpreter)

buf.yaml

@@ -1,8 +1,7 @@
-build:
-  roots:
-    - .
-  excludes:
-    - anapaya/protobuf
+version: v1
+breaking:
+  use:
+    - FILE
 lint:
   use:
     - DEFAULT

go.mod

@@ -1,6 +1,7 @@
 module github.com/scionproto/scion
 
 require (
+	connectrpc.com/connect v1.16.2
 	github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20220209173558-ad29539cd2e9
 	github.com/bazelbuild/rules_go v0.47.1
 	github.com/buildkite/go-buildkite/v2 v2.9.0

go.sum

@@ -1,4 +1,6 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+connectrpc.com/connect v1.16.2 h1:ybd6y+ls7GOlb7Bh5C8+ghA6SvCBajHwxssO2CGFjqE=
+connectrpc.com/connect v1.16.2/go.mod h1:n2kgwskMHXC+lVqb18wngEpF95ldBHXjZYJussz5FRc=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=

go_deps.bzl

@@ -13,6 +13,12 @@ def go_deps():
         sum = "h1:YGD4H+SuIOOqsyoLOpZDWcieM28W47/zRO7f+9V3nvo=",
         version = "v0.4.5",
     )
+    go_repository(
+        name = "com_connectrpc_connect",
+        importpath = "connectrpc.com/connect",
+        sum = "h1:ybd6y+ls7GOlb7Bh5C8+ghA6SvCBajHwxssO2CGFjqE=",
+        version = "v1.16.2",
+    )
     go_repository(
         name = "com_github_ajstarks_svgo",
         importpath = "github.com/ajstarks/svgo",

pkg/proto/control_plane/v1/control_planeconnect/BUILD.bazel

@@ -0,0 +1,17 @@
+load("//tools/lint:go.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "cppki.connect.go",
+        "drkey.connect.go",
+        "renewal.connect.go",
+        "seg.connect.go",
+    ],
+    importpath = "github.com/scionproto/scion/pkg/proto/control_plane/v1/control_planeconnect",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/proto/control_plane:go_default_library",
+        "@com_connectrpc_connect//:go_default_library",
+    ],
+)