Raw logs are stored in a versioned binary format and must be update with
atopconvert(1) upon atop version updates.
Failure to do so results in atop.service startup failure as I found out
the hard way after the "atop: 2.6.0 -> 2.7.1"[0] bump:
```
May 31 01:49:25 <hostname> sh[2269709]: existing file /var/log/atop/atop_20220531 has incompatible header
May 31 01:49:25 <hostname> sh[2269709]: (created by version 2.6 - current version 2.7)
May 31 01:49:25 <hostname> systemd[1]: atop.service: Main process exited, code=exited, status=7/NOTRUNNING
```
Convert logs in `ExecStartPre` and replace them iff updated.
This is to avoid changing original modification times upon every service
start and thus work against atop's log rotation (see existing
`ExecStartPre`).
0: https://github.com/NixOS/nixpkgs/pull/175180#issuecomment-1141546487
systemd-247 provides a mechanism called LoadCredential for secrets and
it is better than environment file. See the section of Environment=
in the manual of systemd.exec for more information.
Some options in config.yaml need values to be strings, which currently
can be used with environmentFile but not loadCredential. But it's
possible to use loadCredential for those options, e.g. we can
substitute their values in ExecStart, but not in ExecStartPre due to
[1].
[1]: https://github.com/systemd/systemd/issues/19604
Prior to this patch:
$ nix-instantiate --eval -E '
> with import ./. {
> localSystem.config = "aarch64-unknown-linux-musl";
> };
> (nixos {}).config.nixpkgs.localSystem.config
> '
"aarch64-unknown-linux-gnu"
Because only the system triple was being passed through, the Musl part
of the system specification was lost. This patch fixes various
occurrences of NixOS evaluation when a Nixpkgs evaluation is already
available, to pass through the full elaborated system attribute set,
to avoid this loss of precision.
Since, 4ddc78818e systemd-boot-builder
is broken in two ways:
* if no systemd-boot is currently installed *and* the NIXOS_INSTALL_BOOTLOADER
env variable is not set, it will try to run "bootctl update", which will fail
* if the currently installed systemd-boot version is newer than the version
we're about to install, it will also try to run "bootctl update", which will fail
This patch changes the behaviour,
* for the first case to still fail, but not even bother to try running
"bootctl update" and instead erroring out with an exception
* for the second case to leave the newer version in place, restoring
the pre - 4ddc78818e behaviour
To do the proper version check a new "should_update" helper function was introduced,
mimicing the compare_product C function from bootctl. If the following systemd
issue gets resolved, we would have a nice way to get rid of this function:
> https://github.com/systemd/systemd/issues/23450
This change allows to again switch to a different NixOS configuration which contains
an older systemd-boot.
Co-authored-by: Martin Weinelt <mweinelt@users.noreply.github.com>
- initialSystem was keeping track of the evaluating system
- it had been used by `nesting.children`
- since, 20.09, `nesting.children` has been replaced with named
specializations
It appears that this option was left over and not cleand up properly.
`extra-utils` composes the set of programs and libraries needed by
1. copying over all programs
2. copying over all libraries any program directly links against
3. set the runtime path for every program to the library directory
It seems that this approach misses the case where a library itself links
against another library. That is to say, `extra-utils` assumes that
either only progams link against libraries or that every library linked
to by a library is already linked to by a program.
`mount.zfs` linking against `libcrypto`, in turn linking against `libdl`
shows how the current approach falls short:
```
$ objdump -p $(which mount.zfs) | grep NEEDED | grep -e libdl -e libcrypto
NEEDED libcrypto.so.1.1
$ ldd (which mount.zfs) | grep libdl
libdl.so.2 => /nix/store/ybkkrhdwdj227kr20vk8qnzqnmj7a06x-glibc-2.34-115/lib/libdl.so.2 (0x00007f9967a9a000
```
Using `mount.zfs` directly in stage 1 init still works since
`LD_LIBRARY_PATH` overrides this (as intended).
util-linux's `mount` however executes `mount.zfs` with LD_LIBRARY_PATH
removed from its environment as can be seen with strace(1) in an
interactive stage 1 init shell (`boot.shell_on_fail` kernel parameter):
```
# env -i LD_LIBRARY_PATH=$LD_LIBRARY_PATH $(which strace) -ff -e trace=/exec -v -qqq $(which mount) /mnt-root
execve("/nix/store/3gqbb3swgiy749fxd5a4k6kirkr2jr9n-extra-utils/bin/mount", ["/nix/store/3gqbb3swgiy749fxd5a4k"..., "/mnt-root"], ["LD_LIBRARY_PATH=/nix/store/3gqbb"...]) = 0
[pid 1026] execve("/sbin/mount.zfs", ["/sbin/mount.zfs", "<redacted>", "/mnt-root", "-o", "rw,zfsutil"], []) = 0
/sbin/mount.zfs: error while loading shared libraries: libdl.so.2: cannot open shared object file: No such file or directory
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=1026, si_uid=0, si_status=127, si_utime=0, si_stime=0} ---
```
env(1) is used for clarity (hence subshells for absoloute paths).
While `mount` uses the right library path, `mount.zfs` is stripped of
it, so ld.so(8) fails resolve `libdl` (as required by `libcrypto`).
To fix this and not rely on `LD_LIBRARY_PATH` to be set, fix the library
path inside libraries as well.
This finally mounts all ZFS filesystems using `zfsutil` with correct and
intended mount options.
At least pkgs/os-specific/linux/util-linux/default.nix uses
```
"--enable-fs-paths-default=/run/wrappers/bin:/run/current-system/sw/bin:/sbin"
```
which does not cover stage 1 init's PATH as all executables are put
under /bin/.
Fix util-linux's `mount` usage by symlinking /sbin to it.
Consider ZFS filesystems meant to be mounted with zfs.mount(8), e.g.
```
config.fileSystems."/media".options = [ "zfsutil" ];
config.fileSystems."/nix".options = [ "zfsutil" ];
```
`zfsutil` uses dataset properties as mount options such that zfsprops(7)
do not have to be duplicated in fstab(5) entries or manual mount(8)
invocations.
Given the example configuation above, /media is correctly mounted with
`setuid=off` translated into `nosuid`:
```
$ zfs get -Ho value setuid /media
off
$ findmnt -t zfs -no options /media
rw,nosuid,nodev,noexec,noatime,xattr,posixacl
```
/nix however was mounted with default mount(8) options:
```
$ zfs get -Ho value setuid /nix
off
$ findmnt -t zfs -no options /nix
rw,relatime,xattr,noacl
```
This holds true for all other ZFS properties/mount options, including
`exec/[no]exec`, `devices/[no]dev`, `atime/[no]atime`, etc.
/nix is mounted using BusyBox's `mount` during stage 1 init while /media
is mounted later using proper systemd and/or util-linux's `mount`.
Tracing stage 1 init showed that BusyBox never tried to execute
mount.zfs(8) as intended by `zfsutil`.
Replacing it with util-linux's `mount` and adding the mount helper
showed attempts to execute mount.zfs(8).
Ensure ZFS filesystems are mounted with correct options iff `zfsutil` is
used.
