Software
Engineer
← All courses
Advanced·9 lessons·99 min

Containers From Scratch

Build a container by hand from the Linux primitives underneath it — namespaces, cgroups, chroot, veth pairs, NAT, and copy-on-write snapshots. No container runtime is installed at any point, and by the end the whole stack stops being magic.

Start — What a Container Really Is
  1. 01What a Container Really IsNot a small VM — a process that has been lied to. 9 min
  2. 02NamespacesThe mechanism that decides what a process can see. 12 min
  3. 03The Root Filesystemchroot, a real Alpine userland, and why /proc has to be mounted. 10 min
  4. 04Copy-on-Writebtrfs snapshots, and what an image layer actually is. 11 min
  5. 05NetworkingA network namespace, a bridge, and a virtual cable between them. 12 min
  6. 06NATThree iptables rules that get a private address onto the internet. 10 min
  7. 07Control GroupsCapping what a container consumes, and where OOMKilled comes from. 11 min
  8. 08Assembling a ContainerOne command, four cages, and a shell that believes it owns the machine. 12 min
  9. 09Cleanup, and What Docker AddsTearing it down, and the debugging map the whole thing adds up to. 12 min