Static socat Build for Linux (amd64)

This repository provides a Docker-based workflow for compiling a static socat binary for Linux/amd64.
It uses Alpine Linux and Docker to produce a portable binary that can be copied directly to your host.
Custom patches are applied to xio-ip4.c and xio-proxy.c before compilation.

📦 Features

• Static build (LDFLAGS=-static) for maximum portability
• Cross-platform builds using Docker --platform (works on ARM, x86_64 hosts, etc.)
• Automatic export of compiled binary to host machine
• Includes custom patched source files
• Cleanup of old build containers/images before building
• Simple one-command build via run.sh

🛠 Requirements

• Docker 18.09+ (BuildKit optional, not required for run.sh)
• Internet connection to download build dependencies
• Bash shell to run the helper script

⚡ Recommended Build Method

The easiest way to build is by running the provided run.sh script:

./run.sh

This script will:

1. Stop and remove any previous build-socat-container container
2. Remove the old build-socat image if it exists
3. Build a fresh Docker image for linux/amd64
4. Run the build inside a container
5. Copy the resulting socat binary to the current directory (./socat)

Note: This method ensures a clean rebuild every time.

run.sh Content

#!/bin/bash
docker stop build-socat-container && docker rm build-socat-container

if [ $? == 0 ]
then
    image=$(docker image ls | grep build-socat | awk '{print $3}')
    docker rmi $image
fi

docker build --platform linux/amd64 -t socat-builder . && \
docker run --rm --platform linux/amd64 -v ./:/out socat-builder sh -c "/build-socat.sh && cp /tmp/socat-1.7.3.2/socat /out/"

🖥 Manual Build Methods

Using Docker BuildKit --output

DOCKER_BUILDKIT=1 docker build \
    --platform linux/amd64 \
    --output type=local,dest=./ .

After completion, the compiled binary will be available at:

./socat

Running the Build Inside a Container (no cleanup)

docker build --platform linux/amd64 -t socat-builder .
docker run --rm --platform linux/amd64 \
    -v ./:/out \
    socat-builder \
    sh -c "/build-socat.sh && cp /tmp/socat-1.7.3.2/socat /out/"

📂 Repository Structure

.
├── build-socat.sh       # Script to configure and compile socat (static build)
├── Dockerfile           # Build environment definition
├── run.sh               # Recommended helper script (with cleanup + build)
├── socat-1.7.3.2.tar.gz # Original socat source code archive
├── xio-ip4.c            # Custom patched source file
├── xio-proxy.c          # Custom patched source file
└── README.md

📜 License

socat is licensed under the GPL v2. This repository contains build scripts and patches and is provided as-is without warranty.

If you save this as `README.md`, it will fully document:
- Your project purpose
- How to use `run.sh`
- The script contents
- Alternative build methods
- Repository file structure
- License info