Chown grpc socket based on config

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

cmd/containerd/config.go

@@ -58,6 +58,8 @@ func (c *config) decodePlugin(name string, v interface{}) error {
 
 type grpcConfig struct {
 	Socket string `toml:"socket"`
+	Uid    int    `toml:"uid"`
+	Gid    int    `toml:"gid"`
 }
 
 type debug struct {

cmd/containerd/main.go

@@ -330,6 +330,9 @@ func serveGRPC(server *grpc.Server) error {
 	if err != nil {
 		return err
 	}
+	if err := os.Chown(path, conf.GRPC.Uid, conf.GRPC.Gid); err != nil {
+		return err
+	}
 	go func() {
 		defer l.Close()
 		if err := server.Serve(l); err != nil {