DNS Checker CLI

A powerful command-line tool for DNS lookups, SSL certificate inspection, and HTTP pinging.

Features

• 🔍 DNS Record Lookup: Query A, AAAA, CNAME, MX, TXT records
• 🔒 SSL Certificate Inspection: Detailed certificate information and expiration warnings
• 📡 HTTP Ping: Real-time HTTP/HTTPS request monitoring with server IP change detection
• 🎨 Rich Output: Visually rich terminal output
• ⚙️ Custom Nameserver: Specify custom DNS servers for queries

Installation

Requirements

• Python 3.7 or higher

Installation Steps

# Clone the repository
git clone <repository-url>
cd dns-checker-cli

# Create virtual environment (recommended)
python -m venv venv
source venv/bin/activate  # macOS/Linux
# or
venv\Scripts\activate  # Windows

# Install dependencies
pip install -r requirements.txt

# Install in development mode
pip install -e .

Usage

DNS Record Lookup

Query DNS records for a domain.

# Basic usage
dns-checker dns example.com

# Use custom nameserver
dns-checker dns example.com --nameserver 8.8.8.8
dns-checker dns example.com -n 1.1.1.1

SSL Certificate Inspection

Query both DNS information and SSL certificate for a domain.

# Basic usage
dns-checker inspect example.com

# Use custom nameserver
dns-checker inspect example.com --nameserver 8.8.8.8

Output Information:

• DNS records (A, AAAA, CNAME, MX, TXT)
• SSL certificate issuer and subject
• Certificate validity period
• SAN (Subject Alternative Names)
• Signature algorithm
• Expiration warning (within 30 days)

HTTP Ping

Periodically send HTTP/HTTPS requests to monitor server status.

# Basic usage (1 second interval, infinite loop)
dns-checker httping https://example.com

# Specify interval (2 seconds)
dns-checker httping https://example.com --interval 2
dns-checker httping https://example.com -i 2

# Specify count (10 times)
dns-checker httping https://example.com --count 10
dns-checker httping https://example.com -c 10

# Use custom nameserver
dns-checker httping https://example.com --nameserver 8.8.8.8

# Force connection to specific IP (keep domain but change IP)
dns-checker httping https://naver.com --server 223.130.200.219
dns-checker httping https://example.com -s 93.184.216.34

# Combined usage
dns-checker httping https://example.com -i 2 -c 20 -n 8.8.8.8 -s 93.184.216.34

Output Information:

• Response time (milliseconds)
• HTTP status code
• Server IP address
• Content-Length (response size)
• Content-Type (response type)
• IP change detection (migration monitoring)
• Forced IP connection indicator
• Statistics (average/min/max response time, success rate)

Stop: Press Ctrl+C to stop and display statistics.

Usage Examples

Domain Migration Monitoring

# Monitor domain during migration to new server
dns-checker httping https://mysite.com -i 5

# Server IP changes will be highlighted

Test with Specific IP

# Request to specific IP while keeping domain as naver.com
# Host header remains naver.com, works with virtual host environments
dns-checker httping https://naver.com --server 223.130.200.219 -c 5

# Test new server before migration
dns-checker httping https://mysite.com --server 192.168.1.100 -c 10

DNS Propagation Check

# Check DNS records with multiple nameservers
dns-checker dns example.com -n 8.8.8.8
dns-checker dns example.com -n 1.1.1.1
dns-checker dns example.com -n 208.67.222.222

SSL Certificate Expiration Check

# Check certificate expiration date
dns-checker inspect example.com

# Warning displayed if expiring within 30 days

Options

Common Options

• --help: Show help message
• --version: Show version information

DNS Command Options

• --nameserver, -n: Custom nameserver IP address

Inspect Command Options

• --nameserver, -n: Custom nameserver IP address

HTTPing Command Options

• --interval, -i: Request interval in seconds (default: 1)
• --count, -c: Number of requests (infinite if not specified)
• --nameserver, -n: Custom nameserver IP address
• --server, -s: Force connection to specific server IP (keep domain but use specific IP)

Development

Development Environment Setup

# Install development dependencies
make dev

# Or manually
pip install -r requirements.txt
pip install pytest pytest-cov pytest-mock flake8 black
pip install -e .

Running Tests

# Using Makefile (recommended)
make test           # Run all tests
make test-cov       # Run tests with coverage

# Or run directly
pytest
pytest tests/test_dns_service.py
pytest --cov=dns_checker

Code Quality

make lint           # Run code linting
make format         # Format code
make verify         # Full verification (lint + tests)

Build and Deploy

make build          # Build package
make upload-test    # Upload to TestPyPI
make upload         # Upload to PyPI
make release        # Full release (test → build → upload)

For more details, see PYPI_UPLOAD_GUIDE.md.

Code Style

This project follows the PEP 8 style guide.

Dependencies

• click>=8.0.0: CLI framework
• dnspython>=2.0.0: DNS queries
• cryptography>=3.4.0: SSL certificate parsing
• requests>=2.25.0: HTTP requests
• rich>=10.0.0: Terminal output formatting

License

MIT License

Contributing

Issues and pull requests are welcome!