Subject: bug#71226: ‘guix shell -C’ doesn’t work on Ubuntu 24.04

From: Ludovic Courtès <[email-masked]>
Date: Fri, 10 Jan 2025 17:37:29 +0100

Hello!

I believe the attached AppArmor profile should work.  You need to:

  1. Drop it in /etc/apparmor.d/guix (it’s actually not specific to
     ‘guix shell -C’ since it matches any ‘guix’ command!).

  2. Run “apparmor_parser -rv /etc/apparmor.d/guix”.

And then you can check “guix build whatever” and “guix shell -C hello”.

Note that AppArmor is stateful: it memorizes previous rules (“profiles”)
and it’s not entirely clear how to remove them, especially when there’s
no profile name.

So perhaps you’ll want to reboot if in doubt.

Anyway, I tested it in an Ubuntu 24.04 VM and everything seemed to work
well.

If you can confirm, we can add it to the repo and have ‘guix-install.sh’
install it.

Ludo’.

abi <abi/3.0>,

include <tunables/global>

profile guix /gnu/store/{*-guix-command,*/bin/guix} flags=(attach_disconnected) {
  include <abstractions/base>
  include <abstractions/consoles>
  include <abstractions/nameservice>

  capability net_admin, # for "guix shell -CN"
  capability sys_admin, # for clone
  capability sys_ptrace, # for user namespaces

  # Allow preparing file systems inside the container root
  mount fstype=(devpts) none -> /tmp/guix-directory.*/dev/pts/,
  mount fstype=(mqueue) options=(nodev, noexec, nosuid, rw) mqueue -> /tmp/guix-directory.*/dev/mqueue/,
  mount fstype=(proc) options=(nodev, noexec, nosuid, rw) none -> /tmp/guix-directory.*/proc/,
  mount fstype=(sysfs) options=(nodev, noexec, nosuid, ro) none -> /tmp/guix-directory.*/sys/,
  mount fstype=(tmpfs) none -> /tmp/guix-directory.*/**,
  mount fstype=(tmpfs) none -> /tmp/guix-directory.*/,
  mount fstype=(tmpfs) options=(nodev, noexec, nosuid, rw) tmpfs -> /tmp/guix-directory.*/dev/shm/,
  mount fstype=(tmpfs) options=(noexec, rw, strictatime) none -> /tmp/guix-directory.*/dev/,
  mount options=(bind, rw) /** -> /tmp/guix-directory.*/**,
  mount options=(rbind, relatime, remount, ro) -> /tmp/guix-directory.*/**/,
  mount options=(rbind, relatime, remount, ro) -> /tmp/guix-directory.*/**,
  mount options=(rbind, rw) /** -> /tmp/guix-directory.*/**,
  umount /real-root/,

  pivot_root,

  # 'guix substitute' is responsible for deduplicating files that it downloads
  # so it needs to be able to create links in /gnu/store/.links.
  link /gnu/store/.links/** -> /gnu/store/**,

  # Note: This also needs to provide permissions for 'guix substitute',
  # which accesses /etc/guix/acl, /var/guix, /gnu/store/.links, etc.

  /etc/nsswitch.conf r,
  /etc/passwd r,
  /gnu/store/** r,
  /gnu/store/**/** r,
  /gnu/store/*-guix-*/etc/ld.so.cache r,
  /gnu/store/*-guix-*/libexec/guix/guile ix,
  /gnu/store/*/bin/* mrix,
  /gnu/store/*/lib/**.so** mr,
  /gnu/store/*/lib/lib*.so* mr,
  /gnu/store/*/libexec/** ix,
  /gnu/store/*/sbin/* mrix,
  /tmp/ rw,
  /tmp/guix-directory** rw,
  /var/guix/** r,
  /var/guix/daemon-socket/socket rw,
  @{PROC}/*/ns/net rw,
  @{PROC}/*/ns/user rw,
  @{PROC}/@{pid}/** rw,
  @{PROC}/self/ rw,
  @{PROC}/self/** rw,
  @{PROC}/sys/kernel/unprivileged_userns_clone rw,

  # These are permissions inside the container after pivot root
  owner / w,
  owner /bin/ w,
  owner /bin/sh w,
  owner /etc/ w,
  owner /etc/group w,
  owner /etc/group.* r,
  owner /etc/group.* w,
  owner /etc/hosts w,
  owner /etc/passwd rw,
  owner /etc/passwd.* r,
  owner /etc/passwd.* w,
  
  owner /home/*/* ra,
  owner /home/*/.cache/guix/profiles/ r,
  owner /home/*/.cache/guix/profiles/* w,
  owner /home/*/.cache/guix/profiles/last-expiry-cleanup r,
  owner /real-root/ w,

  allow userns,

}