Automate WAN IP Resolution with PullHomeIP Script

A simple shell script to resolve and export the current WAN IP address of a home network by querying multiple public DNS resolvers. The script logs results and updates an environment file with the resolved IP.

Features

• Resolves a predefined hostname (jayburd.duckdns.org) via multiple public DNS resolvers (Cloudflare, Google, Quad9).
• Falls back to system DNS resolution methods if public resolvers fail.
• Exports the resolved IP address to an environment file (~/.home_ip.env).
• Maintains a log of resolution attempts and outcomes.

Tech Stack

• Shell scripting (Bash)
• Uses standard Unix utilities: dig, host, getent, ping, awk

Getting Started

Prerequisites

• Bash shell
• dig utility (usually from bind-utils or dnsutils package)
• Optional: host, getent, ping for fallback DNS resolution

Installation

Clone the repository:

git clone https://github.com/justin-napolitano/pullhomeip.git
cd pullhomeip

Make the script executable:

chmod +x pull_home_ip.sh

Usage

Run the script directly:

./pull_home_ip.sh

This will update the ~/.home_ip.env file with the current WAN IP and append logs to ~/.local/share/duckdns/pull_ip.log.

To load the IP into your shell environment:

source ~/.home_ip.env

Project Structure

pullhomeip/
└── pull_home_ip.sh   # Main script to resolve and export WAN IP

• pull_home_ip.sh: Bash script that performs DNS resolution and logging.

Future Work / Roadmap

• Parameterize the hostname instead of hardcoding jayburd.duckdns.org.
• Add options to specify output environment file and log location.
• Support IPv6 resolution.
• Add unit tests or integration tests.
• Provide Docker containerization for easier deployment.
• Add cron job installation instructions or automation.

This project assumes the user wants a lightweight, reliable way to update their WAN IP environment variable for scripts or other automation that depends on the current external IP address.