nixos-config/modules/mullvad/update.sh

#!/usr/bin/env bash
# This gets the current wireguard relay list from mullvad’s API and transforms
# it into a format that takes up less space than the original response.
set -euo pipefail
curl -s 'https://api.mullvad.net/www/relays/wireguard/' | jq '. | map({
	key: (if .hostname | endswith("-wireguard") then .hostname | split("-")[0] else .hostname | sub("-wg-"; "-") end),
	value: {
		endpoint4: .ipv4_addr_in,
		endpoint6: .ipv6_addr_in,
		pubkey: .pubkey
	}
}) | from_entries' > relays.json