It’s been over a year since I started working with Docker — building images, running containers, using Docker Compose, mapping ports, and doing all the regular containerization tasks.
But recently, I decided to go deeper.
Not just how to use Docker, but how Docker really works with the kernel.
And honestly, it’s fascinating.
The Kernel: The Real Magic Behind the Scenes
The kernel is the heart of any operating system. It manages processes, memory, networking, and communication — the core plumbing that everything else relies on.
Over the past two decades, the kernel has evolved into a highly optimized, smooth-running foundation for modern computing. And Docker simply taps into that magic using a set of powerful kernel features.
Key Kernel Features Docker Uses
1. chroot
chroot changes the apparent root directory for a process, locking it into its own filesystem view. This gives processes a scoped, isolated environment.
2. Namespaces
Namespaces isolate system resources — process IDs, network interfaces, mount points, and more — so each container feels like its own little world.
3. cgroups (Control Groups)
Control Groups limit and allocate CPU, memory, and I/O to containers, ensuring they don’t consume more than their fair share of resources.
Why This Matters
So far, I’ve explored these three features — but Docker uses much more behind the scenes to provide isolation, efficiency, and portability.
Once you understand these fundamentals, it’s much easier to dive into advanced container topics, troubleshoot complex issues, or even appreciate the elegance of how containers achieve their “virtual machine feel” without the heavy overhead.
Must-Watch References 🎥
If you want to understand Docker at a much deeper level, I can’t recommend these enough.
They’re not just good — they’re the kind of content you can binge-watch like your favorite Netflix series.
1️⃣ https://www.youtube.com/watch?v=sK5i-N34im8&t=2795s
2️⃣ https://www.youtube.com/watch?v=8fi7uSYlOdc
After watching these, you’ll gain so much clarity — and from there, you can explore any part of Docker’s internals with confidence.
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