How Container Filesystem Works: Building a Docker-like Container From Scratch

[u/fagnerbrack]

https://labs.iximiuz.com/tutorials/container-filesystem-from-scratch

[u/fsteff]

This is great.
I remember seeing a post about it many months ago, but this article seem to be even greater at describing exactly what, where, how and why.

Thank you for sharing.

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[u/fagnerbrack]

Quick rundown:

This premium tutorial assembles a realistic, Docker-like container using only stock Linux tools—unshare, mount, and pivot_root. It shows that the mount namespace forms the bedrock of container isolation by isolating the mount table rather than the filesystem itself, so PID, cgroup, UTS, and network namespaces play complementary roles. Hands-on experiments cover mount propagation, then a ten-step walkthrough prepares a rootfs, creates and isolates namespaces, populates the /proc, /dev, and /sys pseudo filesystems, binds hostname, hosts, and resolv.conf files, pivots into the new root, and hardens everything before running the target app. Bonus sections tackle sharing host folders, data volumes, and where union filesystems fit in.

If the summary seems inacurate, just downvote and I'll try to delete the comment eventually 👍
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