SSTP VPN Docker Container

A lightweight Alpine Linux Docker container for establishing SSTP VPN connections. Built for ARM64 but works on other architectures.

Features

• Alpine Linux based (minimal footprint)
• SSTP client built from source
• PPP with MSCHAPv2 authentication
• Selective routing (only specified subnets through tunnel)
• Auto-reconnect on connection loss
• Includes sample Bun HTTP server for connectivity testing

Prerequisites

• Docker
• Linux kernel with PPP support

Loading PPP Kernel Modules

modprobe ppp_generic
modprobe ppp_async
modprobe ppp_mppe

# Create /dev/ppp if missing
[ -e /dev/ppp ] || mknod /dev/ppp c 108 0

Quick Start

1. Configure credentials:

   cp credentials.env.example credentials.env
   # Edit credentials.env with your SSTP server details

2. Build:

   docker build -t sstp-docker .

3. Run:

   docker run -d \
     --name sstp-vpn \
     --network host \
     --cap-add NET_ADMIN \
     --device /dev/ppp \
     --env-file credentials.env \
     sstp-docker

Configuration

Environment Variables

Variable	Description
SSTP_SERVER	SSTP server hostname or IP
SSTP_USER	VPN username
SSTP_PASS	VPN password

Docker Options

Option	Purpose
--network host	Required for PPP interface creation
--cap-add NET_ADMIN	Required for routing/interface config
--device /dev/ppp	Required for PPP tunnel

Routing

By default, only 10.11.13.0/24 is routed through the tunnel. Modify entrypoint.sh to change:

ip route add YOUR_SUBNET/MASK dev ppp0

Logs

docker logs -f sstp-vpn

Test Server

The included Bun server (port 3000) provides:

Endpoint	Description
/	Status
/ip	External IP
/health	Health check

License

MIT