🔍 Building a Digital Bouncer: My Quest to Secure Containers with Linux Magic

By Elijah Udom Mar. 19, 2025 10 min read

Contents

🖥️ Understanding the Fundamentals

"Because trying to monitor containers without eBPF is like playing whack-a-mole blindfolded"

What started as a simple container security tool turned into an adventure through kernel panics, parent process deception, and the dark arts of eBPF programming.

What's a Computer Kernel?

Think of your computer as a busy airport:

  • 🛂 Kernel: The strict security chief controlling who gets in/out
  • 🧳 Programs: Passengers trying to reach their destinations

The kernel manages everything - memory, devices, security. Mess with it, and the whole system crashes!

💡 Project Motivation

The Container Security Gap

Modern apps use containers like digital shipping containers, but with a catch:

  • 📦 Good State: Isolated, secure packages
  • 🔥 Danger: Malicious escapes into host system

The Wake-Up Call

63% Containers with excess privileges
14 Escape routes per cluster

🔧 Technical Deep Dive

monitor.bpf.c 
SEC("tracepoint/syscalls/sys_enter_execve")
int monitor_execve(struct pt_regs *ctx) {
    // Check process behavior
    // Critical security checks here
}

How It Works

  1. Attach eBPF probes to critical system checkpoints
  2. Monitor process behavior in real-time
  3. Alert on suspicious activities

💥 Development Challenges

Error Log 
$ uname -r
5.4.0-100-generic # Not Supported

$ apt-get install linux-image-6.8.0
Need 2GB of disk space # 😱
"The most valuable lessons come from the most embarrassing mistakes."

🐛 Hall of Shame: Most Annoying Errors

🔧 Missing Header Files

Spent 2 hours debugging because I forgot #include <unistd.h>

📁 Directory Drama

Learned that computers don't magically create directories

👻 Parent Process Lies

Container processes are masters of deception

Ready to Secure Your Containers?

The eBPF Container Security Monitor is now available on GitHub. It's battle-tested and ready to help you catch container escapes.

Warning: May contain traces of kernel panics