Painlessly setup a new peer on your wireguard server

wg_add_peer.sh

#! /usr/bin/env sh
# Painlessly setup a new peer on your wireguard server
#
# Peer config will be rendered as a QR code that can be
# scanned by a mobile device. The peer public key and 
# IP will be appended to the server's wireguard interface
# config.
#
# Requires qrencode to be installed on the system.
set -e

# Server-related Variables

WG_INTERFACE_FILE=/etc/wireguard/wg0.conf
# Replace with server's public IP or domain and wireguard port
SERVER_ENDPOINT=example.com:51820
SERVER_PUBLIC_KEY=$(cat /etc/wireguard/publickey)

# Peer-related Variables

PEER_PRIVATE_KEY=$(wg genkey)
PEER_PUBLIC_KEY=$(echo -n $PEER_PRIVATE_KEY | wg pubkey)
# Replace with desired wireguard subnet and available address range
PEER_ADDRESS="10.0.0.$(shuf -i 3-253 -n 1)/32"

# ---

PEER_CONFIG="\
[Interface]
PrivateKey = $PEER_PRIVATE_KEY
Address = $PEER_ADDRESS
DNS = 192.168.1.53

[Peer]
PublicKey = $SERVER_PUBLIC_KEY
AllowedIPs = 0.0.0.0/0, ::/0
Endpoint = $SERVER_ENDPOINT
"

# Output peer configuration as scannable QR code
echo -n "$PEER_CONFIG" | qrencode -t ansiutf8

SERVER_PEER_CONFIG="
[Peer]
PublicKey=$PEER_PUBLIC_KEY
AllowedIPs=$PEER_ADDRESS
"

echo "$SERVER_PEER_CONFIG" >> $WG_INTERFACE_FILE
echo "
The following peer config has been appended to $WG_INTERFACE_FILE
---
$SERVER_PEER_CONFIG
---
"