A Login Shell (sciprt) to enable users to select a network namespace where the users want to login

netns-gen.sh

#!/bin/bash

ip=/bin/ip
ifc=/sbin/ifconfig

intf=$1
configdir=ns-configs

if [ "$intf" == "" ]; then
	echo $0 [raw interface]
	exit 1
fi

if [ ! -e /sys/class/net/$intf ]; then
	echo interface $intf does not exist
	exit 1
fi


echo detroy all existing netns
for netns in `$ip netns list`; do
	$ip netns del $netns
done

for x in `seq 3`; do echo -n .; sleep 1; done
echo

# create netns
for config in `ls $configdir`; do
	source $configdir/$config

	vlan_intf=$intf.$VLANID
	netns=$NAME
	ipns="$ip netns exec $netns "

	echo create netns \"$netns\"

	$ip netns add $netns
	$ip link add link $intf name $vlan_intf type vlan id $VLANID
	$ip link set dev $vlan_intf netns $netns
	$ipns $ip link set dev $vlan_intf up
	$ipns $ip link set dev lo up

	$ipns $ifc $vlan_intf $ADDRESS
	$ipns $ip route add to default via $GATEWAY
done

netns-shell.sh

#!/bin/bash

ip=/bin/ip


netnslist=`ls /var/run/netns`

echo
echo
echo "Select routing instance you want to Login:"
echo
printf "    = No. =\t= Instance Name =\n"
printf "    %4d\t%s\n" 0 default

cnt=1
for netns in $netnslist; do
	printf "    %4d\t%s\n" $cnt $netns
	cnt=$(( cnt + 1))
done

echo


echo -n "type a number of a routing instance : "

matched=0
while read ri_num; do

	if [ "$ri_num" == "0" ]; then
		# default is selected
		matched=1
		netns=default
		break
	fi

	cnt=1
	for netns in $netnslist; do

		if [ "$cnt" == "$ri_num" ]; then
			matched=1
			break
		fi
		cnt=$(( cnt + 1))
	done

	if [ $matched -eq 1 ]; then 
		break 
	fi

	echo
	echo routing instance No.$ri_num does not exist.
	echo
	echo -n "type a number of a routing instance : "
done

if [ $matched -ne 1 ]; then
	echo
	exit 0
fi


echo
echo Login to routing instance \"$netns\"
echo

if [ $ri_num -eq 0 ]; then
	# default is selected
	/bin/bash
else
	# login into selected netns
	sudo $ip netns exec $netns /bin/bash
fi