Add script to add peers to Wireguard config

The script is to be run on the VPN host. It extracts the necessary data from
the configuration file and asks for some data about the new peer. It then
outputs the peer configuration file and updates the host configuration
accordingly.

VPS/WireguardAddPeer.sh

@@ -0,0 +1,117 @@
+#!/bin/bash
+
+# Usage : parseConf $fileContent $propertyName
+# Retrieves the value of propertyName from fileContent
+# And echoes it back
+function parseConf() {
+	result=$(echo "$1" | grep $2 | cut -f2 -d'=')
+	echo $result
+}
+
+
+if [ $EUID -ne 0 ]; then
+	echo "This script can only be run as root"
+	exit -1
+fi
+
+if [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
+	cat <<EOF 
+This script adds a peer to a Wireguard configuration and
+outputs the corresponding configuration file.
+
+Usage : 
+$0 [ PATH_TO_WIREGUARD_CONFIGURATIONS ]
+
+EOF
+
+	exit 0
+fi
+
+configurationsPath="/etc/wireguard"
+if [ -d "$1" ]; then
+	configurationsPath="$1"
+fi
+
+# Retrieve every configuration file using a glob.
+# Don't add anything to the array if nothing is present
+shopt -s nullglob
+wireguardConfigs=(/etc/wireguard/*)
+shopt -u nullglob
+
+configCount=${#wireguardConfigs[@]}
+
+if [ $configCount -eq 0 ]; then
+	echo "There are no wireguard configs availabe !"
+	exit -1
+fi
+
+count=0
+echo "Available configurations :"
+for configuration in ${wireguardConfigs[@]}; do
+	echo -e "\t"$count. "$configuration"
+	count=$(($count+1))
+done
+
+invalid=true
+while $invalid; do
+	echo -n "Please choose a configuration: "
+	read choice
+	echo ""
+
+	case $choice in
+		[0-$(($configCount-1))])
+			invalid=false
+		;;
+		'')
+			echo "Exiting"
+			exit 0
+		;;
+		*)
+			echo "Invalid argument, please use the numbers printed before the configurations"
+		;;
+	esac
+done
+
+
+confFile=${wireguardConfigs[$choice]}
+echo "Using $confFile"
+
+
+fileContent="$(cat $confFile)"
+
+listenPort=$(parseConf "$fileContent" ListenPort)
+address=$(parseConf "$fileContent" Address)
+targetDomain=$(echo $(ip -4 -resolve -brief addr show | grep UP) | cut -f3 -d' ' | cut -f1 -d'/')
+# Manually add '=' as we cut with delimiter '='
+pubKey=$(echo $(parseConf "$fileContent" PrivateKey)= | wg pubkey)
+
+
+echo -n "Server address is $address, please enter peer address: "
+read peerAddress
+
+echo -n "Please enter allowed IPs range for peer: "
+read peerAllowedIPs
+
+peerKey=$(wg genkey)
+peerPubKey=$(echo $peerKey | wg pubkey)
+
+cat <<EOF >> $confFile
+
+[Peer]
+PublicKey = $peerPubKey
+AllowedIPs = $peerAddress/32
+
+EOF
+
+cat <<EOF
+[Interface]
+Address = $peerAddress/$(echo $address | cut -f2 -d'/')
+PrivateKey = $peerKey
+
+[Peer]
+PublicKey = $pubKey
+AllowedIPs = $peerAllowedIPs
+Endpoit = $targetDomain:$listenPort
+
+
+EOF