Hey huntrs, Marcello Salvati here, threat researcher at Protect AI. I’m here to give you a crash course on Docker. If you’re diving into security research, Docker can be your best friend. It simplifies spinning up projects for analysis and sidesteps the dependency nightmares that often come with Python and Node ecosystems.

Why Docker Matters for Hackers

Picture this: you’re trying to test a GitHub project, but it’s built on Python or Node, and you’re stuck in dependency hell. Docker solves this by packaging everything you need into a neat little container. No more “it works on my machine” issues. Just spin up the project and start hacking.

For this tutorial, we’ll use a general example to show Docker’s utility—it’s a skill every hacker should have in their arsenal. Let’s dive into the Docker basics before we get hands-on.

Docker Basics

What is Docker?

Docker is a runtime, a program that runs on your machine to handle containerized applications. Think of it as the ultimate compatibility layer. It ensures that applications run identically across environments, be it your laptop or a server.

Key Concepts

• Docker Images: Templates that define your application and dependencies. If you’ve seen a Dockerfile in a repo, it’s the blueprint for building an image.

• Docker Containers: Running instances of images. When you run a container, you’re essentially bringing an image to life.

Hands-On: Running a Docker Container

Step 1: Pull the Docker Image

Identify the project you want to run. Many Docker images can be found on Docker Hub—Docker’s equivalent of PyPI for images.

To pull an image, use:

docker pull <image-name>

This grabs the latest version of the image. To confirm, run:

docker images

You’ll see a list of all images, including the one you just pulled.

Step 2: Run the Container

Most projects include setup instructions. Here’s a general example command:

docker run -p 3001:3001 <image-name>

This command:

• -p 3001:3001: Maps port 3001 from the container to your machine so you can access the app’s web UI.

• No -d flag: Runs in the foreground so you can see the logs.

Once the container is up, navigate to localhost:3001 in your browser. Your app should be running.

Bonus: Using Docker Volumes

For more advanced setups, consider using volumes to share files between your container and host machine. Many Docker guides provide detailed instructions on this.

Advanced Tip: Exec Into a Container

Sometimes, you’ll need to inspect a running container—say, to verify an exploit like a local file inclusion (LFI) or remote file write. Here’s how:

1. Identify the container ID:

docker ps

2. Exec into the container:

docker exec -ti <container-id> bash

You’ll get a shell inside the container to explore its file system or inspect logs. Handy for verifying your findings.

Why This Matters

Docker is a game-changer for security research, especially when testing experimental projects or investigating model file vulnerabilities. Knowing how to set up and use Docker not only streamlines your workflow but also improves report quality. Including setup steps in your Huntr reports helps with faster triage—a win-win for everyone.

So, huntrs, get comfortable with Docker. It’s an essential tool in your bug bounty arsenal. Happy hunting!