msgen — Master Server Generator

Author: Bocaletto Luca

msgen is a cross-platform CLI tool written in Go that scaffolds a standalone, persistent “server” binary. The generated server:

• Runs as a background service/daemon on Windows & Linux
• Auto-starts at boot (Windows Service / systemd unit)
• Automatically restarts on crash or stop (service recovery policy)
• Periodically collects machine info (IP, MAC, hostname, OS, CPU, memory, disk, users)
• Sends templated email reports via SMTP (STARTTLS/SMTPS)
• Is fully self-contained: configuration is embedded or loaded from config.yaml

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🚀 Features

• Single executable (server.exe on Windows, server on Linux)
• Embedded or external YAML configuration
• Cron-style scheduling (@every 30m, 0 8 * * *, etc.)
• System metrics via [gopsutil]
• Email delivery via [gomail] with TLS & retry
• Windows Service integration (register/unregister)
• systemd unit file support for Linux
• Structured console logging (zerolog)
• Dockerfile for containerized deployment
• GitHub Actions CI workflow

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📋 Prerequisites

• Go 1.21+ toolchain
• Git
• On Windows: Administrative privileges to register a Service
• On Linux: systemd environment and sudo for unit deployment

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🔧 Installation

1. Clone the repository and install msgen:

   git clone https://github.com/bocaletto-luca/msgen.git
   cd msgen
   go install ./cmd/msgen

2. Verify msgen is in your $GOPATH/bin or $GOBIN:

   msgen --help

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⚙️ Configuration

Create or edit a YAML config file (config.yaml). You can either keep it alongside your server binary or let it fall back to the embedded default.

# config.yaml
schedule: "@every 30m"

smtp:
  host: "smtp.example.com"
  port: 587
  username: "[email protected]"
  password: "supersecret"
  from: "[email protected]"
  to:
    - "[email protected]"
    - "[email protected]"

modules:
  - ip
  - mac
  - os
  - cpu
  - mem
  - disk
  - users

Environment variable overrides
You may replace any field with ${ENV_VAR} syntax and export the corresponding environment variables before generating or running the server.

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▶️ Generating Your Server

Run msgen pointing at your config:

msgen --config path/to/config.yaml --out ./dist

This will create:

• dist/config.yaml (copied)
• dist/server.go (templated Go source)

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🛠️ Building Executables

Windows

GOOS=windows GOARCH=amd64 go build -o dist/server.exe dist/server.go

Linux

GOOS=linux   GOARCH=amd64 go build -o dist/server   dist/server.go
chmod +x dist/server

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⚙️ Deployment

Windows Service

1. Open PowerShell as Administrator.
2. Register the service:

   sc.exe create ms-server `
     binPath= "C:\path\to\server.exe --config C:\path\to\config.yaml" `
     start= auto
   sc.exe failure ms-server reset= 0 actions= restart/5000

3. Start the service:

   sc.exe start ms-server

4. To stop & remove:

   sc.exe stop ms-server
   sc.exe delete ms-server

Linux systemd Unit

1. Copy binary and config to /opt/ms-server/:

   sudo mkdir -p /opt/ms-server
   sudo cp dist/server /opt/ms-server/
   sudo cp dist/config.yaml /opt/ms-server/

2. Create /etc/systemd/system/ms-server.service:

   [Unit]
   Description=msgen Server Daemon
   After=network.target
   
   [Service]
   ExecStart=/opt/ms-server/server --config /opt/ms-server/config.yaml
   Restart=always
   RestartSec=5
   User=root
   LimitNOFILE=4096
   
   [Install]
   WantedBy=multi-user.target

3. Enable & start:

   sudo systemctl daemon-reload
   sudo systemctl enable ms-server
   sudo systemctl start ms-server

4. Check status & logs:

   sudo systemctl status ms-server
   journalctl -u ms-server -f

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🐳 Docker

Build and run in a container:

docker build -t bocaletto-luca/ms-server .
docker run -d \
  -v $(pwd)/config.yaml:/app/config.yaml:ro \
  -e SMTP_PASSWORD \
  --name ms-server \
  bocaletto-luca/ms-server

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🔍 Health Checks

The server binary exposes a basic HTTP health endpoint at http://localhost:8000/healthz. You can integrate this with load balancers or monitoring systems.

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🧪 Testing & CI

• Unit tests and linters:

  go test ./...
  go vet ./...

• CI workflow on GitHub Actions builds & tests for multiple Go versions.

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📝 License

This project is licensed under the GPL License. See LICENSE for details.

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Author: Bocaletto Luca (@bocaletto-luca)