As of systemd/systemd@e908434458,
systemd-networkd now automatically configures routes to addresses
specified in AllowedIPs unless explicitly disabled with
"RouteTable=off".
When initializing a system (e.g. first boot / livecd) we have no good
reference source for time. systemd-timesyncd however would revert back
to its configured fallback time (in our case 01.01.1980). Since we
probably don't want to hardcode a specific date as fallback we are now
using the current system time (wherever that might have come from) to
initialize the reference clock file.
The only systems that might be remotely affected by this change are
machines that have highly unreliable RTCs or those where the battery
that backs the RTC is running empty.
Historically these systems always had a tough time with anything time
related and likely required manual intervention.
For stateless systems (those that wipe / between reboots or our
installer CDs) this has the consequence that time will always be reset
to whatever the system comes up with on boot. This is likely the correct
time coming from an RTC. No harm done here the situation is likely
unchanged for them.
For stateful systems (those that retain the / partition across reboots)
there shouldn't be a change at all. They'll provide an initial clock
value once on their lifetime (during first boot / after installation).
From then onwards systemd-timesyncd will update the file with the newer
fallback time (that will be picked up on the next boot).
This effectively fixes the majority of all VM tests which were broken
because `/dev/vda` (or any other block device) wasn't mountable:
machine # mounting /dev/vda on /...
machine # mount: mounting /dev/vda on /mnt-root/ failed: No such device[ 2.820976] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000100
machine # [ 2.821757] CPU: 0 PID: 1 Comm: init Not tainted 5.10.72 #1-NixOS
machine # [ 2.821757] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
machine # [ 2.821757] Call Trace:
machine # [ 2.821757] dump_stack+0x6b/0x83
machine # [ 2.821757] panic+0x101/0x2c8
machine # [ 2.821757] do_exit.cold+0x14/0xb3
machine # [ 2.821757] do_group_exit+0x33/0xa0
machine # [ 2.821757] __x64_sys_exit_group+0x14/0x20
machine # [ 2.821757] do_syscall_64+0x33/0x40
machine # [ 2.821757] entry_SYSCALL_64_after_hwframe+0x44/0xa9
machine # [ 2.821757] RIP: 0033:0x7f67ec2800f6
machine # [ 2.821757] Code: 00 4c 8b 0d 2c 5d 11 00 eb 19 66 2e 0f 1f 84 00 00 00 00 00 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 22 f4 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e2 f7 d8 64 41 89 01 eb da 66 2e 0f 1f 84 00
machine # [ 2.821757] RSP: 002b:00007fff8f5a71d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
machine # [ 2.821757] RAX: ffffffffffffffda RBX: 0000000000699704 RCX: 00007f67ec2800f6
machine # [ 2.821757] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
machine # [ 2.821757] RBP: 0000000000000004 R08: 00000000000000e7 R09: ffffffffffffff80
machine # [ 2.821757] R10: 00007f67ec33f3e0 R11: 0000000000000202 R12: 000000000000000b
machine # [ 2.821757] R13: 00007fff8f5a75a8 R14: 0000000000000000 R15: 00000000004fc198
machine # [ 2.821757] Kernel Offset: 0x31e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
machine # [ 2.821757] Rebooting in 1 seconds..
This happened because the kernel failed to load modules such as `ext4`
from `boot.initrd.availableKernelModules`[1] on e.g. a `mount(2)` syscall.
The problem is that `kmod` isn't linked against `libpthread.so.0`
anymore because it got merged into `libc.so.6` (however, the .so still
exists), but still needs it:
machine # newfstatat(AT_FDCWD, "/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-glibc-2.34-36/lib/x86_64", 0x7ffd951114c0, 0) = -1 ENOENT (No such file or directory)
machine # openat(AT_FDCWD, "/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-glibc-2.34-36/lib/x86_64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
machine # newfstatat(AT_FDCWD, "/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-glibc-2.34-36/lib/x86_64", 0x7ffd951114c0, 0) = -1 ENOENT (No such file or directory)
machine # openat(AT_FDCWD, "/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-glibc-2.34-36/lib/libpthread.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
machine # newfstatat(AT_FDCWD, "/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-glibc-2.34-36/lib", 0x7ffd951114c0, 0) = -1 ENOENT (No such file or directory)
machine # openat(AT_FDCWD, "/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-glibc-2.34-36/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
machine # writev(2, [{iov_base="/nix/store/kdc9n48ksdc1a8y8w512w"..., iov_len=69}, {iov_base=": ", iov_len=2}, {iov_base="error while loading shared libra"..., iov_len=36}, {iov_base=": ", iov_len=2}, {iov_base="libpthread.so.0", iov_len=15}, {iov_base=": ", iov_len=2}, {iov_base="cy
machine # ) = 184
machine # exit_group(127) = ?
machine # +++ exited with 127 +++
machine # mount: mounting /dev/vda on /mnt-root/ failed: No such device
machine # [ 19.167180] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000100
machine # [ 19.167711] CPU: 0 PID: 1 Comm: init Not tainted 5.10.72 #1-NixOS
This is not a problem
* inside stage-1 because `LD_LIBRARY_PATH` points to `$out/lib` of
extra-utils where `libpthread.so.6` also exists.
* on a running system because `${pkgs.glibc}/lib` is part of kmod's
rpath.
However this is a problem inside the kernel which calls `modprobe` (in
our case `kmod`) to load modules and doesn't know about
`LD_LIBRARY_PATH`. Also, the rpath-reference was nuked.
To work around this, the kernel's `modprobe`
(i.e. `/proc/sys/kernel/modprobe`) now points to a wrapper which
explicitly declares `LD_LIBRARY_PATH`. We can't use `makeWrapper` here
because `modprobe` itself must not be renamed. Otherwise, `kmod` (which
is the link-target of `modprobe`) won't work because it expects
`argv[0] == "modprobe"` to perform modprobe's tasks.
[1] https://nixos.org/manual/nixos/stable/options.html#opt-boot.initrd.availableKernelModules
wtmp and btmp are created by systemd, so the rules are more appropriate there.
They can be disabled explicitly with something like
services.ogrotate.paths = {
"/var/log/btmp".enable = false;
"/var/log/wtmp".enable = false;
};
if required.
The mount options need to be passed as a comma-separated list of options so that they
end up one a single Options line in the resulting mount unit.
The current code passed the options as a list, resulting in several Options lines in
the mount unit, all but the first of these were ignored by systemd however.
This behaviour is not clearly defined in the systemd man page.
The `nix.*` options, apart from options for setting up the
daemon itself, currently provide a lot of setting mappings
for the Nix daemon configuration. The scope of the mapping yields
convience, but the line where an option is considered essential
is blurry. For instance, the `extra-sandbox-paths` mapping is
provided without its primary consumer, and the corresponding
`sandbox-paths` option is also not mapped.
The current system increases the maintenance burden as maintainers have to
closely follow upstream changes. In this case, there are two state versions
of Nix which have to be maintained collectively, with different options
avaliable.
This commit aims to following the standard outlined in RFC 42[1] to
implement a structural setting pattern. The Nix configuration is encoded
at its core as key-value pairs which maps nicely to attribute sets, making
it feasible to express in the Nix language itself. Some existing options are
kept such as `buildMachines` and `registry` which present a simplified interface
to managing the respective settings. The interface is exposed as `nix.settings`.
Legacy configurations are mapped to their corresponding options under `nix.settings`
for backwards compatibility.
Various options settings in other nixos modules and relevant tests have been
updated to use structural setting for consistency.
The generation and validation of the configration file has been modified to
use `writeTextFile` instead of `runCommand` for clarity. Note that validation
is now mandatory as strict checking of options has been pushed down to the
derivation level due to freeformType consuming unmatched options. Furthermore,
validation can not occur when cross-compiling due to current limitations.
A new option `publicHostKey` was added to the `buildMachines`
submodule corresponding to the base64 encoded public host key settings
exposed in the builder syntax. The build machine generation was subsequently
rewritten to use `concatStringsSep` for better performance by grouping
concatenations.
[1] - https://github.com/NixOS/rfcs/blob/master/rfcs/0042-config-option.md
This option behaves exactly like `boot.extraModprobeConfig`, except that it also includes the generated modprobe.d file in the initrd.
Many years ago, someone tried to include the normal modprobe.d/nixos.conf file generated by `boot.extraModprobeConfig` in the initrd: 0aa2c1dc46. This file contains a reference to a directory with firmware files inside. Including firmware in the initrd made it too big, so the commit was reverted again in 4a4c051a95.
The `boot.extraModprobeConfig` option not changing the initrd caused me much confusion because I tried to set the maximum cache size for ZFS and it didn't work.
Closes https://github.com/NixOS/nixpkgs/issues/25456.
I was confused why I couldn't find a mention of udev.log_priority in
systemd-udevd.service(8). It turns out that it was renamed[1] to
udev.log_level. The old name is still accepted, but it'll avoid
further confusion if we use the new name in our documentation.
[1]: 64a3494c3d
Add `shellDryRun` to the generic stdenv and substitute it for uses of
`${stdenv.shell} -n`. The point of this layer of abstraction is to add
the flag `-O extglob`, which resolves#126344 in a more direct way.
