Wireguard - script to add new client

newclient.sh

#! /bin/bash

clientname=$1

serverconf="wg0.conf"
subnet24="172.20.1."
dns1=176.103.130.130
dns2=176.103.130.131


newprivkey=$(wg genkey)
newpubkey=$(echo $newprivkey | wg pubkey)
lastdigit=$(echo $(cat $serverconf | grep -oP "(?<=AllowedIPs = $subnet24)[^/]*" | sort -n | tail -1) + 1 | bc )
serverpubkey=$(cat $serverconf | grep -P "^\s*PrivateKey" | sed 's/^\s*PrivateKey\s*=\s*\(.*\)$/\1/' | wg pubkey)
listenport=$(cat $serverconf | grep -P "^\s*ListenPort" | sed 's/^\s*ListenPort\s*=\s*\(.*\)$/\1/' )
listenfqdn=$(nslookup $(curl -s ifconfig.me) | grep -oP "(?<=name = ).*(?=[.])")

cat > $clientname.conf << EOF
[Interface]
PrivateKey = ${newprivkey}
Address = ${subnet24}${lastdigit}/24
DNS = ${dns1},${dns2}

[Peer]
PublicKey = $serverpubkey 
Endpoint = ${listenfqdn}:${listenport}
AllowedIPs = 0.0.0.0/0
EOF

cat >> $serverconf << EOF
                                                                                                           
#$clientname                                                                                                   
[Peer]                                                                                                     
publicKey = $newpubkey
AllowedIPs = ${subnet24}${lastdigit}/32

EOF

wg syncconf wg0 <(wg-quick strip wg0)


/usr/bin/qrencode -t ansiutf8 < $clientname.conf

exit 0