18–20 Sept 2024
Europe/Vienna timezone

Isolated user namespaces & cgroupfs

19 Sept 2024, 15:50
20m
"Room 1.15 - 1.16" (Austria Center)

"Room 1.15 - 1.16"

Austria Center

106
Containers and checkpoint/restore MC Containers and checkpoint/restore MC

Speaker

Aleksandr Mikhalitsyn (Canonical)

Description

This talk is about a problem of integration between the concept of an "isolated" ([1], [2], [3], [4]) user namespace and cgroup-v2 delegation model.

The biggest challenge here is that cgroup delegation is based on cgroupfs inodes ownership and cgroupfs superblock is shared between all containers which makes it impossible to deal with cgroupfs as with any other containerized filesystem like procfs or tmpfs.

[1] More flexible user namespaces https://fosdem.org/2024/schedule/event/fosdem-2024-2987-more-flexible-user-namespaces/
[2] User namespaces with host-isolated UIDs/GIDs https://lpc.events/event/17/contributions/1569/
[3] Isolated dynamic user namespaces https://lpc.events/event/7/contributions/836/
[4] Simplified user namespace allocation https://lpc.events/event/11/contributions/982/

Primary author

Co-author

Presentation materials