lightweight ui to change active mullvad server

mullvad-lean.sh

#!/usr/bin/bash

set -euo pipefail

for exe in sudo rofi wg curl jq; do
  type "$exe" &>/dev/null || {
    echo >&2 "please install $exe"
    exit 1
  }
done

cache=${XDG_CACHE_HOME:-~/.cache}/mullvad-lean
mkdir --parents "$cache"
chmod --silent 700 "$cache"

template="$cache"/mv.conf.in
config="$cache"/mv.conf

if [[ ! -f "$template" ]]; then
  echo 'creating wireguard config symlink'

  sudo ln --symbolic --force \
    "$config" /etc/wireguard/mv.conf

  echo 'adding restart wg operation to sudoers'

  sudoers=$(mktemp)
  echo >"$sudoers" "$USER ALL=(ALL:ALL) NOPASSWD: /usr/bin/systemctl restart wg-quick@mv"

  visudo --check --file "$sudoers"

  sudo install -Dm644 --owner root --group root \
    "$sudoers" "/etc/sudoers.d/zz-mullvad-$USER"

  key=$(wg genkey)

  cat >"$template" <<EOF
[Interface]
# Add this public key on mullvad.net: $(wg pubkey <<<"$key")
PrivateKey = $key
Address = IP_V4_AND_V6_OF_YOUR_CLIENT_PROVIDED_BY_MULLVAD

# do not modify variables
[Peer]
PublicKey = \$PUBKEY
Endpoint = \$ENDPOINT:443
AllowedIPs = 0.0.0.0/0,::0/0
EOF

  chmod 600 "$template"

  echo "please copy public key from $template into mullvad.net and update it with your client IP"
  exit
fi

chmod 600 "$config" "$template" || true

get_servers() {
  local out="$cache/servers.json"

  if ! find "$out" -type f -mtime +0 2>/dev/null; then
    curl --silent --show-error --output "$out.tmp" \
      https://api.mullvad.net/www/relays/wireguard

    mv --force "$out.tmp" "$out"
  fi

  cat "$out"
}

server=$(
  get_servers |
    jq --raw-output '.[] | select(.active == true) | "\(.hostname) | \(.country_name) | \(.city_name) | \(.network_port_speed)G | \(.ipv4_addr_in)"' |
    column --table --separator '|' |
    rofi -dmenu -i -p server -no-custom |
    cut --delimiter ' ' --fields 1
)

[[ -z $server ]] && exit

conn=$(
  get_servers |
    jq --raw-output --arg hostname "$server" \
      '.[] | select(.hostname == $hostname) | { ip4: .ipv4_addr_in, key: .pubkey }'
)

[[ -z $conn ]] && exit 1

env --ignore-environment \
  PUBKEY="$(jq --raw-output '.key' <<<"$conn")" \
  ENDPOINT="$(jq --raw-output '.ip4' <<<"$conn")" \
  envsubst <"$template" >"$config"

sudo systemctl restart wg-quick@mv

notify-send "switched to server $server" || true