This service is essentially a random sleep() call that old software that
is unable to properly handle modern hardware initialisation being
asynchronous can use to *mostly* get by.
Over the years is has caused so many issues in NixOS, like introducing
long delays in the boot process[1], complete deadlocks[2] and even failures
when reloading services or activating a new configuration[3].
systemd has been discouraging its use since 2011 (15 years ago!), then
it officially deprecated it in 2018 and since 2020 it started to show on
every boot a huge wall of text calling out all the offending services
that still use it.
Around 2021 we managed to fix around 15 NixOS modules[4] that were
relying on systemd-udev-settle and practically ZFS[5] was the only
remaining one. However, since then, people have actually started to
bring it back with new services[6][7][8]. This is not acceptable.
So, to prevent any more (lazy) uses of systemd-udev-settle, we stop
providing the systemd-udev-settle.service unit entirely. For existing
modules that unfortunately still need it, we replace it with the command
`udevadm settle --timeout=180`, which is all that the service does.
Hopefully this will also increase the awareness that it's bad and
something to be fixed.
Note: I tested this change using
- `nixosTests.zfs`,
- `nixosTests.ifstate`,
- `nixosTests.misc`,
- `nixosTests.openvswitch`,
- `nixosTests.predictable-interface-names`
- `nixosTests.nvidia-container-toolkit`
and making sure that none of the 165 packages that provide upstream
units (via the `systemd.packages` option) had a dependency on
systemd-udev-settle.service.
[1]: https://github.com/NixOS/nixpkgs/pull/25311
[2]: https://github.com/NixOS/nixpkgs/issues/107341
[3]: https://github.com/NixOS/nixpkgs/pull/113804
[4]: https://github.com/NixOS/nixpkgs/issues/73095
[5]: https://github.com/openzfs/zfs/issues/10891
[6]: https://github.com/NixOS/nixpkgs/pull/257525#discussion_r1442702970
[7]: https://github.com/NixOS/nixpkgs/pull/460075
[8]: https://github.com/NixOS/nixpkgs/pull/284507
After final improvements to the official formatter implementation,
this commit now performs the first treewide reformat of Nix files using it.
This is part of the implementation of RFC 166.
Only "inactive" files are reformatted, meaning only files that
aren't being touched by any PR with activity in the past 2 months.
This is to avoid conflicts for PRs that might soon be merged.
Later we can do a full treewide reformat to get the rest,
which should not cause as many conflicts.
A CI check has already been running for some time to ensure that new and
already-formatted files are formatted, so the files being reformatted here
should also stay formatted.
This commit was automatically created and can be verified using
nix-build a08b3a4d19.tar.gz \
--argstr baseRev b32a094368
result/bin/apply-formatting $NIXPKGS_PATH
these changes were generated with nixq 0.0.2, by running
nixq ">> lib.mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> Inherit >> mdDoc[remove]" --batchmode nixos/**.nix
two mentions of the mdDoc function remain in nixos/, both of which
are inside of comments.
Since lib.mdDoc is already defined as just id, this commit is a no-op as
far as Nix (and the built manual) is concerned.
Systemd dependencies for scripted mode
were refactored according to analysis in #34586.
networking.vswitches can now be used with systemd-networkd,
although they are not supported by the daemon, a nixos receipe
creates the switch and attached required interfaces (just like
the scripted version).
Vlans and internal interfaces are implemented following the
template format i.e. each interface is
described using an attributeSet (vlan and type at the moment).
If vlan is present, then interface is added to the vswitch with
given tag (access mode). Type internal enabled vswitch to create
interfaces (see openvswitch docs).
Added configuration for configuring supported openFlow version on
the vswitch
This commit is a split from the original PR #35127.
Openvswitch was upgraded to the latest
stable version (currenty 2.12.0). This remove ovs-monitor-ipsec
commands.
LTS version is still available using
`config.virtualisation.vswitch.package = pkgs.openvswitch-lts`
it has been upgraded to 2.5.6.
This commit is a split from the original PR #35127.
- add missing types in module definitions
- add missing 'defaultText' in module definitions
- wrap example with 'literalExample' where necessary in module definitions
