wg_namespace_cli

#!/usr/bin/env bash

# A simple script that manages network namespace routed through a wireguard interface
# Usage:
# $0 [up|down]
# Some configuration is available through environment variables
# See manual for details
#
# Author: Vladimir Timofeenko <vladimir@vtimofeenko.com>
# Bugs-to: https://github.com/VTimofeenko/wireguard-namespace-service/issues
# License: Unlicense

set -euo pipefail
set -o errtrace
set -x

# STOCK_SERVICE variable should be set by the accompanying systemd service
if [ -z ${STOCK_SERVICE+x} ]; then
    BASE_CONF_DIR=${CREDENTIALS_DIRECTORY:-'/etc/wireguard'}
else
    BASE_CONF_DIR=${BASE_CONF_DIR:-'/etc/wireguard'}
fi

command="$1"
conf_file="$2"

# The default name to be used for link name, config file name, etc.
# Useful to override all of them at the same time
DEFAULT_NAME="wg0"

NAMESPACE_NAME=${NAMESPACE_NAME:-${DEFAULT_NAME}}
LINK_NAME=${LINK_NAME:-${DEFAULT_NAME}}
WG_CONF_FILE=${WG_CONF_FILE:-"${BASE_CONF_DIR}/${conf_file:-"${DEFAULT_NAME}"}.conf"}

trap down ERR

up() {
    if [ -z ${MY_IP+x} ]; then
        echo "MY_IP variable is unset, please set it"
        exit 1;
    fi

    ip netns add "$NAMESPACE_NAME"
    # create the interface
    ip link add "${LINK_NAME}" type wireguard
    # move the ${LINK_NAME} device into netns
    ip link set "${LINK_NAME}" netns "$NAMESPACE_NAME"
    # set device config
    ip netns exec "${NAMESPACE_NAME}" wg setconf "${LINK_NAME}" "${WG_CONF_FILE}"
    ip -n "${NAMESPACE_NAME}" addr add "${MY_IP}" dev "${LINK_NAME}"
    ip -n "${NAMESPACE_NAME}" link set mtu 1420 up dev "${LINK_NAME}"
    # all routing will go through "${LINK_NAME}"
    ip -j -n "${NAMESPACE_NAME}" route add default dev "${LINK_NAME}"
    echo "Namespace ${NAMESPACE_NAME} is up"
}

down() {
    ip -n "${NAMESPACE_NAME}" link set down dev "${LINK_NAME}"
    ip -n "${NAMESPACE_NAME}" link del dev "${LINK_NAME}"
    ip netns del "${NAMESPACE_NAME}"
    echo "Namespace ${NAMESPACE_NAME} is down"
}


case "$command" in
    up) up "$@" ;;
    down) down "$@" ;;
esac