wireguard-ns.sh

#!/bin/bash

if [ ${USER} != "root" ]
then
	echo "${0}: rerun as root" 1>&2
	exit 1
fi

function cleanup() {
	# delete the existing interfaces
	ip -n client link del wgc 2> /dev/null
	ip -n server link del wgs 2> /dev/null

	# delete the existing namespaces
	ip netns del client 2> /dev/null
	ip netns del router 2> /dev/null
	ip netns del server 2> /dev/null

	# delete existing interfaces
	ip link del wg0 2> /dev/null
	ip link del wg0 2> /dev/null
}
# in case cleanup required
trap cleanup EXIT

# generate keys
cpriv="$(wg genkey)"
spriv="$(wg genkey)"
cpub="$(wg pubkey <<<"$cpriv")"
spub="$(wg pubkey <<<"$spriv")"

# delete existing interfaces
ip -n client link del wgc 2> /dev/null
ip -n server link del wgs 2> /dev/null

# delete existing namespaces
ip netns del client 2> /dev/null
ip netns del router 2> /dev/null
ip netns del server 2> /dev/null

# delete existing interfaces
ip link del wg0 2> /dev/null
ip link del wg0 2> /dev/null

# create network namespaces
ip netns add client
ip netns add router
ip netns add server

# set loopback up
ip -n client link set lo up
ip -n router link set lo up
ip -n server link set lo up

# create wg interfaces and move them to namespaces
ip -n router link add dev wgc type wireguard
ip -n router link add dev wgs type wireguard
ip -n router link set wgc netns client
ip -n router link set wgs netns server

# assign IP addresses to each of the interfaces
ip -n client addr add 10.0.0.1/24 dev wgc
ip -n server addr add 10.0.0.2/24 dev wgs

# configure wireguard interfaces and add peers
ip netns exec client wg set wgc \
	private-key <(echo "$cpriv") \
	listen-port 12121 \
	peer "$spub" \
		allowed-ips 10.0.0.2 \
		endpoint 127.0.0.1:13131
ip netns exec server wg set wgs \
	private-key <(echo "$spriv") \
	listen-port 13131 \
	peer "$cpub" \
		allowed-ips 10.0.0.1 \
		endpoint 127.0.0.1:12121

# set the interfaces up
ip -n client link set wgc up
ip -n server link set wgs up

# verify setup using ping
ip netns exec client ping -c 100 -f 10.0.0.2
ip netns exec client ping -c 100 -f 10.0.0.1

# print out wg status
ip netns exec client wg
ip netns exec server wg