if err != nil {
		return nil, err
	}
	if filter != nil && !filter.Contains(uid) {
		return nil, nil
	}

	netns, err := proc.Open(netnsName)
	if err != nil {
		return nil, err
	}
	fd, err := GetFd(netns)
	if err != nil {
		netns.Close()
		return nil, err
	}
	netnsObserved[inode] = struct{}{}
	log.Debugf("found pod to netns: %s %d", uid, inode)

	return &PodNetnsEntry{
		uid:     uid,