Darpan 🪞

दर्पण (Darpan) = Mirror in Hindi/Sanskrit
Your development environment, reflected in real-time

Zero-config service monitoring for Linux developers. Auto-discovers and monitors databases, APIs, Docker containers, and caches with real-time health checks, live log streaming, and network activity tracking.

cargo install darpan
darpan watch  # That's it!

✨ What You Get

Before Darpan 😓

$ systemctl status postgresql redis nginx
$ docker ps | grep mongo
$ lsof -i :3000,5432,6379
$ curl localhost:8000/health
$ journalctl -u postgresql -f
$ tail -f /var/log/nginx/error.log

6 commands. 6 terminal tabs. Constant context switching.

With Darpan ✨

$ darpan watch

┌─ Darpan - myproject | Live Monitor ─────────────────┐
│ STATUS    │ NAME        │ TYPE      │ PORT  │ CONN  │
├───────────┼─────────────┼───────────┼───────┼───────┤
│ ✓ Healthy │ PostgreSQL  │ Database  │  5432 │ 3     │
│ ✓ Healthy │ Redis       │ Cache     │  6379 │ 0     │
│ ✓ Healthy │ Frontend    │ HTTP      │  3000 │ 1     │  ← Works without /health!
│ ✗ Down    │ API Server  │ HTTP      │  8000 │ -     │
└──────────────────────────────────────────────────────┘
3/4 healthy | Enter: details | L: logs | r: refresh

One command. One dashboard. Everything.

🚀 Key Features

🔍 Zero-Config Auto-Discovery

• Instant detection: PostgreSQL, Redis, MySQL, MongoDB, Docker, HTTP servers
• Multi-source scanning: Ports, processes, Docker API, systemd units
• Smart recognition: Service signatures and common patterns
• Just works: No setup required

💚 Intelligent Health Monitoring

• Multi-tier checks: HTTP endpoints → Port connectivity → Process verification
• Database pings: PostgreSQL, Redis, MySQL, MongoDB
• Fallback logic: Services without /health work (React, Vue, Angular dev servers)
• Real-time updates: Configurable intervals

📡 Live Network Activity Tracking ⚡ NEW

═══ Network Activity ═══
Port Status: LISTENING ✓
Active Connections: 5 (traffic detected)
Process Connections: 3 established, 1 listening

• See actual traffic to your services
• Detect hung connections or leaks
• Verify listening status even without health endpoints
• Process-level insights for deep debugging

🔍 Real-Time Log Streaming

┌─ SERVICE LOGS: Redis ─────────────────────────┐
│ [12:30:45 INFO ] Starting Redis 7.0.15        │
│ [12:30:46 INFO ] Ready to accept connections  │
│ [12:30:50 WARN ] Memory usage: 2.1MB          │
└───────────────────────────────────────────────┘
Press /: search | 1-4: filter level | E: export

Auto-detects 4 log sources:

• 🐳 Docker: stdout/stderr from all containers
• ⚙️ Systemd: journalctl integration
• 📁 Files: /var/log/, ./logs/, ~/.pm2/logs/
• ⚡ Process: Direct stdout/stderr via /proc/<pid>/fd/

Interactive features:

• Search with / (highlighted matches)
• Filter: 1=ERROR, 2=WARN, 3=INFO, 4=DEBUG
• Pause/scroll with Space, ↑↓
• Export with E to ~/.config/darpan/logs/

🎨 Beautiful TUI

• Keyboard-driven (Vim-style j/k support)
• Color-coded status indicators
• Live auto-refresh
• Service details with diagnostics
• Network activity section

📦 Installation

# From crates.io (recommended)
cargo install darpan

# From source
git clone https://github.com/codeBunny2022/darpan.git
cd darpan
cargo install --path .

# Verify
darpan --version  # v0.2.2

Requirements: Rust 1.70+, Linux
Optional: Docker, systemd, ss/netstat

🎯 Quick Start

Basic Commands

darpan watch              # Interactive TUI (recommended)
darpan status             # Quick CLI status
darpan why "Redis"        # Troubleshoot specific service
darpan status --format json  # For scripts/CI
darpan init               # Create .darpan.yml template

TUI Navigation

Log Viewer (Press L)

📚 Configuration (Optional)

Darpan works without config. Add .darpan.yml only for custom services:

version: 1

services:
  - name: My API
    type: http_server
    port: 8000
    health_check:
      type: http
      path: /api/health
    log_file: /var/log/myapi/app.log  # Custom log path
    
  - name: PostgreSQL
    type:
      database: postgres
    port: 5432
    health_check:
      type: postgres
      database: mydb
    systemd_unit: postgresql.service  # Custom systemd unit
    
  - name: Worker
    type: custom
    port: 9000
    process: "python worker.py"
    tags: [background, critical]

dependencies:
  - service: My API
    depends_on: [PostgreSQL, Redis]

Config locations:

• ./.darpan.yml - Project-level (team sharing)
• ~/.config/darpan/config.yml - User-level (personal defaults)

🌟 Real-World Examples

Example 1: Microservices Stack

$ cd ~/my-microservices
$ darpan watch

# See all services:
# - 3 Docker containers (MongoDB, RabbitMQ, Elasticsearch)
# - 2 Node.js APIs (ports 3000, 4000)
# - 1 React frontend (port 8080)
# - PostgreSQL and Redis

# Press L on any service to see live logs
# Press Enter to see network connections

Example 2: Debugging Slow API

$ darpan watch

# Select API service → Press Enter
# Check "Network Activity":
#   Active Connections: 127 (!!!)
#   → Connection leak detected!

# Press L → Search for "timeout" with /
# Press E → Export logs for analysis

Example 3: CI/CD Health Check

#!/bin/bash
# Ensure all services are up before running tests

darpan status --format json | jq '.[] | select(.status != "Healthy")'
if [ $? -eq 0 ]; then
  echo "Some services are down!"
  darpan status
  exit 1
fi

npm test

🔧 Troubleshooting

Service not detected?

# Check if port is open
ss -tln | grep 5432

# Check if process is running
ps aux | grep postgres

# Add to .darpan.yml manually
darpan init

Logs not showing?

# Check permissions
ls -la /var/log/postgresql/

# For systemd logs
journalctl -u redis-server -f

# For Docker
docker logs <container_name>

# Specify custom log path in .darpan.yml

Health check false positive/negative?

# Override in .darpan.yml
services:
  - name: My Service
    port: 3000
    health_check:
      type: http
      path: /custom/health  # Custom endpoint
      expected_status: 200

🤝 Contributing

Contributions welcome! Please see CONTRIBUTING.md for:

• Code of conduct
• Development setup
• Pull request process
• Testing guidelines

📄 License

MIT License - see LICENSE for details.

Created by Chirag (chiraglabs)

🙏 Acknowledgments

Built with:

• Ratatui - Terminal UI
• Tokio - Async runtime
• Bollard - Docker API
• Serde - Serialization

Inspired by tools like htop, docker-compose, and systemctl status.

💬 Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Crates.io: crates.io/crates/darpan