// relative to /run/secrets/ position.
	if isFile(pathJoin("/run/secrets/", sp)) {
		sp = pathJoin("/run/secrets/", sp)
	}
	credBuf, err := os.ReadFile(sp)
	if err != nil {
		if os.IsNotExist(err) { // ignore if file doesn't exist.
			return "", nil
		}
		return "", err
	}
	return string(bytes.TrimSpace(credBuf)), nil
}

func loadEnvVarsFromFiles() {