// not. The check is a simple file existence check.
//
// https://github.com/moby/moby/blob/master/daemon/initlayer/setup_unix.go
// https://github.com/containers/podman/blob/master/libpod/runtime.go
//
//	"/.dockerenv":        "file",
//	"/run/.containerenv": "file",
func IsDocker() bool {
	var err error
	for _, envfile := range []string{
		"/.dockerenv",