Add a io.podman.v1.Noop GRPC service to the podman system service

Add a bare minimum GRPC service to the podman system service socket.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

Author: nalind

pkg/api/grpcpb/build.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+set -e
+cd $(dirname ${BASH_SOURCE[0]})
+TOP=../../..
+PATH=${TOP}/test/tools/build:${PATH}
+set -x
+for proto in *.proto ; do
+	protoc \
+		--go_opt=paths=source_relative --go_out . \
+		--go-grpc_opt=paths=source_relative --go-grpc_out . \
+	${proto}
+done

pkg/api/grpcpb/noop.pb.go

@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package io.podman.v1;
+
+option go_package = "github.com/containers/podman/v6/pkg/api/grpcpb";
+
+service Noop {
+  rpc Noop(NoopRequest) returns (NoopResponse);
+}
+
+message NoopRequest {
+  string ignored = 1;
+}
+
+message NoopResponse {
+  string ignored = 1;
+}

pkg/api/grpcpb/noop.proto

@@ -0,0 +1,26 @@
+//go:build !remote
+
+package grpc
+
+import (
+	"context"
+
+	"github.com/containers/podman/v6/libpod"
+	"github.com/containers/podman/v6/pkg/api/grpcpb"
+)
+
+type noopServer struct {
+	grpcpb.UnimplementedNoopServer
+	runtime *libpod.Runtime
+}
+
+func (noopServer) Noop(_ context.Context, req *grpcpb.NoopRequest) (*grpcpb.NoopResponse, error) {
+	resp := &grpcpb.NoopResponse{
+		Ignored: req.GetIgnored(),
+	}
+	return resp, nil
+}
+
+func NewNoopServer(runtime *libpod.Runtime) grpcpb.NoopServer {
+	return &noopServer{runtime: runtime}
+}