On bookworm, AppArmor failed to start inside the container, which can be
seen at startup of the dev-container:
Created symlink /etc/systemd/system/systemd-firstboot.service → /dev/null.
Created symlink /etc/systemd/system/systemd-udevd.service → /dev/null.
Created symlink /etc/systemd/system/multi-user.target.wants/docker-entrypoint.service → /etc/systemd/system/docker-entrypoint.service.
hack/dind-systemd: starting /lib/systemd/systemd --show-status=false --unit=docker-entrypoint.target
systemd 252.17-1~deb12u1 running in system mode (+PAM +AUDIT +SELINUX +APPARMOR +IMA +SMACK +SECCOMP +GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT +QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK -XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified)
Detected virtualization docker.
Detected architecture x86-64.
modprobe@configfs.service: Deactivated successfully.
modprobe@dm_mod.service: Deactivated successfully.
modprobe@drm.service: Deactivated successfully.
modprobe@efi_pstore.service: Deactivated successfully.
modprobe@fuse.service: Deactivated successfully.
modprobe@loop.service: Deactivated successfully.
apparmor.service: Starting requested but asserts failed.
proc-sys-fs-binfmt_misc.automount: Got automount request for /proc/sys/fs/binfmt_misc, triggered by 49 (systemd-binfmt)
+ source /etc/docker-entrypoint-cmd
++ hack/make.sh dynbinary test-integration
When checking "aa-status", an error was printed that the filesystem was
not mounted:
aa-status
apparmor filesystem is not mounted.
apparmor module is loaded.
Checking if "local-fs.target" was loaded, that seemed to be the case;
systemctl status local-fs.target
● local-fs.target - Local File Systems
Loaded: loaded (/lib/systemd/system/local-fs.target; static)
Active: active since Mon 2023-11-27 10:48:38 UTC; 18s ago
Docs: man:systemd.special(7)
However, **on the host**, "/sys/kernel/security" has a mount, which was not
present inside the container:
mount | grep securityfs
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
Interestingly, on `debian:bullseye`, this was not the case either; no
`securityfs` mount was present inside the container, and apparmor actually
failed to start, but succeeded silently:
mount | grep securityfs
systemctl start apparmor
systemctl status apparmor
● apparmor.service - Load AppArmor profiles
Loaded: loaded (/lib/systemd/system/apparmor.service; enabled; vendor preset: enabled)
Active: active (exited) since Mon 2023-11-27 11:59:09 UTC; 44s ago
Docs: man:apparmor(7)
https://gitlab.com/apparmor/apparmor/wikis/home/
Process: 43 ExecStart=/lib/apparmor/apparmor.systemd reload (code=exited, status=0/SUCCESS)
Main PID: 43 (code=exited, status=0/SUCCESS)
CPU: 10ms
Nov 27 11:59:09 9519f89cade1 apparmor.systemd[43]: Not starting AppArmor in container
Same, using the `/etc/init.d/apparmor` script:
/etc/init.d/apparmor start
Starting apparmor (via systemctl): apparmor.service.
echo $?
0
And apparmor was not actually active:
aa-status
apparmor module is loaded.
apparmor filesystem is not mounted.
aa-enabled
Maybe - policy interface not available.
After further investigating, I found that the non-systemd dind script
had a mount for AppArmor, which was added in 31638ab2ad
The systemd variant was missing this mount, which may have gone unnoticed
because `debian:bullseye` was silently ignoring this when starting the
apparmor service.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
