$ PID=`sudo lsns -t net -n -o PID,COMMAND | grep rtkit-daemon | cut -d ' ' -f 2`
$ sudo nsenter -t $PID -n
# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
# ls /sys/class/net
docker0  enp3s0  lo  lxcbr0  ...

/sys/class/net
    Each  of the entries in this directory is a symbolic link representing
    one of the real or virtual networking devices that are visible in
    the network namespace of the process that is accessing the directory.