Wireguard

Introduction

Using a VPN allows remote access to a server’s local resources without exposing them to the internet. It’s a clean and secure way to access services like SSH without exposing the port publicly. With a VPN, you can securely connect to your network from anywhere and make devices on different networks communicate.

Here we will use Wireguard, a secure and high-performance VPN server, using containers:

• wg-easy as the server, providing a very simple web UI to manage connections and download config files (including QR codes for phones)
• Wireguard as the client for Linux systems

Clients are also available for Windows, macOS, iOS, and Android.

The concept:

• On the internet, anyone can reach any internet box and thus any exposed server.
• Your server is on your local network. It is accessible only locally unless services are explicitly exposed (as we did with Dockge). To access non-exposed resources, you must be on the same local network.
• We want to securely access these unexposed services (like SSH) from anywhere.
• We also want to connect services between servers, like linking two Dockge instances securely.

To achieve this, we’ll create a Virtual Private Network (VPN), i.e., a secure tunnel that only connected machines can use. They’ll appear to be on the same private network.

Additionally, you can add your phone, laptop, or other devices to the VPN and securely access your server resources wherever you are.

In this diagram, machine 1 is part of two networks:

• Its local network (devices behind the same router, e.g. 192.168.x.x – machines 1 and 2)
• The VPN network (VPN devices with a second IP, e.g. 10.8.x.x – machines 1 and 4)

You can allow VPN clients to share access to their local networks, but we won’t do that here for security and subnet conflict reasons (e.g., if two remote machines use the same local IP like 192.168.1.1).

So only VPN-connected devices can communicate with each other on the VPN, not with other local devices outside the VPN.

Server Setup

Folder Structure

root
└── docker
    └── wg-easy
        ├── config
        │   └── etc_wireguard
        ├── compose.yaml
        └── .env

Open Dockge, click Compose, and name the stack wg_easy.

Copy the following configuration:

---
services:
  wg-easy:
    environment:
      - INSECURE=true
    image: ghcr.io/wg-easy/wg-easy:15
    container_name: wg-easy
    networks:
      wg:
        ipv4_address: 10.42.42.42
        ipv6_address: fdcc:ad94:bacf:61a3::2a
    volumes:
      - ./etc_wireguard:/etc/wireguard
      - /lib/modules:/lib/modules:ro
    ports:
      - "51820:51820/udp"
      - "51821:51821/tcp"
    restart: unless-stopped
    cap_add:
      - NET_ADMIN
      - SYS_MODULE
    sysctls:
      - net.ipv4.ip_forward=1
      - net.ipv4.conf.all.src_valid_mark=1
      - net.ipv6.conf.all.disable_ipv6=0
      - net.ipv6.conf.all.forwarding=1
      - net.ipv6.conf.default.forwarding=1

networks:
  wg:
    driver: bridge
    enable_ipv6: true
    ipam:
      driver: default
      config:
        - subnet: 10.42.42.0/24
        - subnet: fdcc:ad94:bacf:61a3::/64

services:
  wg-easy:
    # ...
    labels:
      - com.centurylinklabs.watchtower.enable=true

Deploy the stack and access the local web UI at http://server-ip:51821.

Once connected, follow the web UI instructions to:

• Create your admin account and password.
• Set the host field (use your public IP or domain name).

Then go to Administrator → Admin Panel → Config:

• Change Allowed IPs from 0.0.0.0/24 to 10.8.0.0/24 for split tunneling.
• Remove IPv6 (it often causes unnecessary issues).

Retrieve Configuration Files

To configure clients:

1. Access the web UI: http://server-ip:51821
2. Create a new client
3. Edit the client and add 10.8.0.0/24 to Server Allowed IPs
4. (Optional) Set Persistent Keep Alive to 25 if it’s a permanently connected client
5. Save, download, and rename the file to wg0.conf (or wg1.conf, etc.)

Client Server Setup

Folder Structure

root
└── docker
    └── wireguard
        └── config
        │   └── wg_confs
        └── compose.yaml

Create the folder:

sudo mkdir -p /docker/wireguard/config/wg_confs

Create the wg0.conf file:

sudo vi /docker/wireguard/config/wg_confs/wg0.conf

Enter insert mode (i), paste the downloaded configuration, then save (Esc → :x).

sudo cp ~/wg0.conf /docker/wireguard/config/wg_confs

Create the compose.yaml file in /docker/wireguard:

services:
  wireguard:
    image: lscr.io/linuxserver/wireguard:latest
    container_name: wireguard
    network_mode: host
    cap_add:
      - NET_ADMIN
      - SYS_MODULE
    environment:
      - TZ=Europe/Paris
    volumes:
      - /docker/wireguard/config:/config
      - /lib/modules:/lib/modules
    restart: unless-stopped

Start the container:

cd /docker/wireguard
sudo docker compose up -d

Other Devices

• Mobile: Install WireGuard and scan the QR code via the web UI (http://server-ip:51821)
• Desktop: Install the WireGuard client and import the downloaded config file.

And here’s the final setup overview: