OpenWRT script to dynamically assign Wireguard NordVPN host based on closest or country

nordvpn.sh

#!/bin/sh

#set -x

URL="https://api.nordvpn.com/v1/servers/recommendations?&filters\[servers_technologies\]\[identifier\]=wireguard_udp&limit=1"

if [[ -n "$DRY" ]]; then
	uci() {
		echo "uci: $@"
	}
fi

if [[ "$1" == "off" ]]; then
	uci set network.wg_nordvpn_peer.public_key=""
	uci set network.wg_nordvpn_peer.endpoint_host=""
        uci commit network.wg_nordvpn_peer
        ifup wg_nordvpn
        echo "NordVPN disabled."
	exit 0
fi

if [[ -n "$1" ]]; then
	if COUNTRY_ID=$(curl -s "https://api.nordvpn.com/v1/servers/countries" | jq -e "[.[] | select(.code == \"$1\" or .name == \"$1\")][0].id"); then
		URL="$URL&filters\[country_id\]=$COUNTRY_ID"
	else
		echo "Failed to find country: $1."
		exit 1
	fi
fi

if curl -s --fail-with-body -o /tmp/wireguard/nordvpn.json "$URL"; then
	if ! HOST=$(jq -e -r '.[]|.hostname' /tmp/wireguard/nordvpn.json); then
		echo "No NordVPN hostname found."
		exit 1
	fi

	uci set network.wg_nordvpn_peer.public_key=$(jq -r '(.[]|.technologies|.[].metadata|.[].value)' /tmp/wireguard/nordvpn.json)
	uci set network.wg_nordvpn_peer.endpoint_host="$HOST"
	if uci changes network.wg_nordvpn_peer | grep "^"; then
		uci commit network.wg_nordvpn_peer
		ifup wg_nordvpn
		echo "New NordVPN peer: $HOST"
	else
		echo "The NordVPN peer not changed: $HOST"
	fi
else
	echo "Could not get new NordVPN peer..."
	cat /tmp/wireguard/nordvpn.json
	exit 1
fi

1. Write content to nordvpn.sh.
2. Install jq: opkg update && opkg install jq.
3. Set chmod +x nordvpn.sh.
4. Run ./nordvpn.sh to set closest server, or ./nordvpn.sh France or ./nordvpn.sh FR.

The NordVPN Wireguard has to be preconfigured in /etc/config/network:

config interface 'wg_nordvpn'
	option proto 'wireguard'
	option private_key 'NORDVPN-CLIENT-PRIVATE-KEY'
	list addresses '10.5.0.2/32'

config wireguard_wg_nordvpn 'wg_nordvpn_peer'
	option endpoint_port '51820'
	option persistent_keepalive '25'
	option route_allowed_ips '1'
	list allowed_ips '0.0.0.0/0'
	list allowed_ips '::/0'