LogWisp - Simple Log Streaming

A lightweight log streaming service that monitors files and streams updates via Server-Sent Events (SSE).

Philosophy

LogWisp follows the Unix philosophy: do one thing and do it well. It monitors log files and streams them over HTTP/SSE. That's it.

Features

• Monitors multiple files and directories
• Streams log updates in real-time via SSE
• Supports both plain text and JSON formatted logs
• Automatic file rotation detection
• Simple TOML configuration
• No authentication or complex features - use a reverse proxy if needed

Quick Start

1. Build:

./build.sh

2. Run with defaults (monitors current directory):

./logwisp

3. View logs:

curl -N http://localhost:8080/stream

Configuration

LogWisp looks for configuration at ~/.config/logwisp.toml. If not found, it uses sensible defaults.

Example configuration:

port = 8080

[monitor]
check_interval_ms = 100

[[monitor.targets]]
path = "/var/log"
pattern = "*.log"

[[monitor.targets]]
path = "/home/user/app/logs"
pattern = "app-*.log"

[stream]
buffer_size = 1000

API

• GET /stream - Server-Sent Events stream of log entries

Log entry format:

{
  "time": "2024-01-01T12:00:00Z",
  "source": "app.log",
  "level": "error",
  "message": "Something went wrong",
  "fields": {"key": "value"}
}

Building from Source

Requirements:

• Go 1.23 or later

go mod download
go build -o logwisp ./src/cmd/logwisp

Usage Examples

Basic Usage

# Start LogWisp (monitors current directory by default)
./logwisp

# In another terminal, view the stream
curl -N http://localhost:8080/stream

With Custom Config

# Create config
cat > ~/.config/logwisp.toml << EOF
port = 9090

[[monitor.targets]]
path = "/var/log/nginx"
pattern = "*.log"
EOF

# Run
./logwisp

Production Deployment

For production use, consider:

1. Run behind a reverse proxy (nginx, caddy) for SSL/TLS
2. Use systemd or similar for process management
3. Add authentication at the proxy level if needed
4. Set appropriate file permissions on monitored logs

Example systemd service:

[Unit]
Description=LogWisp Log Streaming Service
After=network.target

[Service]
Type=simple
User=logwisp
ExecStart=/usr/local/bin/logwisp
Restart=always

[Install]
WantedBy=multi-user.target

Design Decisions

• No built-in authentication: Use a reverse proxy
• No TLS: Use a reverse proxy
• No complex features: Follows Unix philosophy
• File-based configuration: Simple, no CLI args needed
• SSE over WebSocket: Simpler, works everywhere

License

BSD-3-Clause