wireguard-docker

Wireguard setup in Docker meant for a simple personal VPN. There are currently 3 flavors:

buster - docker pull cmulk/wireguard-docker:buster
stretch - docker pull cmulk/wireguard-docker:stretch
alpine - docker pull cmulk/wireguard-docker:alpine (install-module not supported on alpine)

Use the flavor (buster or stretch) that corresponds to your host machine if the kernel module install feature is going to be used.

Overview

This docker image and configuration is my simple version of a wireguard personal VPN, used for the goal of security over insecure (public) networks, not necessarily for Internet anonymity. The debian (stretch and buster) flavors of the image have the ability to install the wireguard kernel module on the host, and the host OS must also use the same version of debian if this feature is going to be used. In addition, the host's /lib/modules directory needs to be mounted on the first run to install the module (see the Running section below). Thanks to activeeos/wireguard-docker for the general structure of the docker image - it is the same concept just built on Ubuntu 16.04.

In my use case, I'm running the wireguard docker image on a free-tier Google Cloud Platform debian virtual machine and connect to it with Android, Linux, and a GL-Inet router as clients.

Running

First Run (stretch or buster only)

If the wireguard kernel module is not already installed on the host system, use this first run command to install it:

docker run -it --rm --cap-add sys_module -v /lib/modules:/lib/modules cmulk/wireguard-docker:buster install-module

Normal Run

docker run --cap-add net_admin --cap-add sys_module -v <config volume or host dir>:/etc/wireguard -p <externalport>:<dockerport>/udp cmulk/wireguard-docker:buster

Example:

docker run --cap-add net_admin --cap-add sys_module -v wireguard_conf:/etc/wireguard -p 5555:5555/udp cmulk/wireguard-docker:buster

Generate Keys

This shortcut can be used to generate and display public/private key pairs to use for the server or clients

docker run -it --rm cmulk/wireguard-docker:buster genkeys

Configuration

Sample server-side interface configuration to go in /etc/wireguard (e.g., wg0.conf):

[Interface]
Address = 192.168.20.1/24
PrivateKey = <server_private_key>
ListenPort = 5555

[Peer]
PublicKey = <client_public_key>
AllowedIPs = 192.168.20.2

Sample client configuration:

[Interface]
Address = 192.168.20.2/24
PrivateKey = <client_private_key>
ListenPort = 0 #needed for some clients to accept the config

[Peer]
PublicKey = <server_public_key>
Endpoint = <server_public_ip>:5555
AllowedIPs = 0.0.0.0/0,::/0 #makes sure ALL traffic routed through VPN
PersistentKeepalive = 25

Other Notes

This Docker image also has a iptables NAT (MASQUERADE) rule already configured to make traffic through the VPN out to the Internet work. This can be disabled by setting the environment variable IPTABLES_MASQ=0.
For some clients (a GL.inet router in my case) you may have trouble with HTTPS (SSL/TLS) due to the MTU on the VPN. Ping and HTTP work fine but HTTPS does not for some sites. This can be fixed with MSS Clamping. This is simply a checkbox in the OpenWRT Firewall settings interface.
It's possible to watch for changes to any of the configuration files in /etc/wireguard (in the container) and automatically restart wireguard as soon as one changes. This is very useful when combining this docker image with a wireguard GUI. To enable watching for changes, set the environment variable WATCH_CHANGES=1.

Use as client

This image can be used as a "client" as well. If you want to forward all traffic through the VPN (AllowedIPs = 0.0.0.0/0), you need to use the --privileged flag when running the container, or you got error Read-only file system.
If you got error RTNETLINK answers: Permission denied, you need to use the --sysctl net.ipv6.conf.all.disable_ipv6=0 flag.

Client example

docker run -d \
--privileged \
--restart=always \
--name wireguard-client \
--cap-add NET_ADMIN \
--cap-add SYS_MODULE \
--sysctl net.ipv6.conf.all.disable_ipv6=0 \
-v <client config dir>wg0.conf:/etc/wireguard/wg0.conf \
cmulk/wireguard-docker:alpine

Example connect to client from another container

docker run -it --rm --net=container:wireguard-client alpine wget -q -O - ipinfo.io/ip

docker-compose

Sample docker-compose.yml

version: "2"
services:
 vpn:
  image: cmulk/wireguard-docker:buster
  volumes:
   - /etc/wireguard:/etc/wireguard
  networks:
   - net
  ports:
   - 5555:5555/udp
  restart: unless-stopped
  cap_add:
   - NET_ADMIN
   - SYS_MODULE

networks:
  net:

Build

Since the images are already on Docker Hub, you only need to do this if you want to change something

git clone https://github.com/cmulk/wireguard-docker.git
cd wireguard-docker

docker build -f Dockerfile.buster -t wireguard:local .
### OR ###
docker build -f Dockerfile.stretch -t wireguard:local .
### OR ###
docker build -f Dockerfile.alpine -t wireguard:local .