similar to "ip vrf exec" for linux kernel 4.9

ip-vrf-exec

#!/bin/sh

EXEC=

ARG="$@"
VRF=$1

if [ "x$USER" != "xroot" ]; then
  echo "Root privileges are required for this operation"
  exit 1
fi
ip link show $VRF > /dev/null 2>&1
if [ "$?" != 0 ]; then
  echo "VRF $VRF does not exist."
  exit 1
fi
ip link show $VRF | grep MASTER > /dev/null 2>&1
if [ "$?" != 0 ]; then
  echo "$VRF is not VRF."
  exit 1
fi
cgget -r l3mdev.master-device $VRF 2>&1 | grep cannot > /dev/null 2>&1
if [ "$?" = 0 ]; then
  $EXEC cgcreate -g l3mdev:$VRF
fi
$EXEC cgset -r l3mdev.master-device=$VRF $VRF
$EXEC cgexec -g l3mdev:$ARG