Yes, this function name is inconveniently long, but it is important
for the name to explicitly reference the function and not be mistaken
for the implicit string conversions, which only happen for a smaller
set of values.
The placement of this option under `nix` was misleading, as it is not
configuration of the Nix daemon, but rather configuration of the NixOS
boot process and how it mounts the Nix store. As such, make it an option
of `boot` to clarify what it actually affects, and imply that it will
only take effect on a reboot.
Since it no longer has the context of nix, adjust the name to include
it.
Currently paths are handled by `types.package`, whose semantics are a
bit of a mess. In particular, it converts path values to derivations
using `toDerivation`, which will lead to problems when flake `outPath`s
become paths in https://github.com/NixOS/nix/pull/6530.
This change makes the "incompatible changes" section in the above PR
obsolete: `nix.registry.nixpkgs.flake = nixpkgs;` works as expected (the
flake is copied to the store).
conversions were done using https://github.com/pennae/nix-doc-munge
using (probably) rev f34e145 running
nix-doc-munge nixos/**/*.nix
nix-doc-munge --import nixos/**/*.nix
the tool ensures that only changes that could affect the generated
manual *but don't* are committed, other changes require manual review
and are discarded.
When `nix.registry.<name>.flake` option is used, additional attributes of the flake were not written to the flake registry file because of a missing parenthesis.
now nix-doc-munge will not introduce whitespace changes when it replaces
manpage references with the MD equivalent.
no change to the manpage, changes to the HTML manual are whitespace only.
our xslt already replaces double line breaks with a paragraph close and
reopen. not using explicit para tags lets nix-doc-munge convert more
descriptions losslessly.
only whitespace changes to generated documents, except for two
strongswan options gaining paragraph two breaks they arguably should've
had anyway.
the conversion procedure is simple:
- find all things that look like options, ie calls to either `mkOption`
or `lib.mkOption` that take an attrset. remember the attrset as the
option
- for all options, find a `description` attribute who's value is not a
call to `mdDoc` or `lib.mdDoc`
- textually convert the entire value of the attribute to MD with a few
simple regexes (the set from mdize-module.sh)
- if the change produced a change in the manual output, discard
- if the change kept the manual unchanged, add some text to the
description to make sure we've actually found an option. if the
manual changes this time, keep the converted description
this procedure converts 80% of nixos options to markdown. around 2000
options remain to be inspected, but most of those fail the "does not
change the manual output check": currently the MD conversion process
does not faithfully convert docbook tags like <code> and <package>, so
any option using such tags will not be converted at all.
The Nix-provided `nix-daemon.socket` file has a
> ConditionPathIsReadWrite=/nix/var/nix/daemon-socket/socket
line, to skip that unit if /nix/var/nix/daemon-socket/socket is
read-only (which is the case in some nixos-containers with that folder
bind-ro-mounted from the host).
In these cases, the unit was skipped.
Systemd 250 (rightfully) started to also skip in these cases:
> [ 237.187747] systemd[1]: Nix Daemon Socket was skipped because of a failed condition check (ConditionPathIsReadWrite=/nix/var/nix/daemon-socket).
However, systemd < 250 didn't skip if /nix/var/nix/daemon-socket/socket
didn't /exist at all/, and we were relying on this bug in the case for
fresh NixOS systems, to have /nix/var/nix/daemon-socket/socket created
initially.
Move the creation of that folder to systemd-tmpfiles, by shipping an
appropriate file in `${nixPackage}/lib/tmpfiles.d/nix-daemon.conf`
(NixOS/nix#6285).
In the meantime, set a systemd tmpfiles rule manually in NixOS.
This has been tested to still work with read-only bind-mounted
/nix/var/nix/daemon-socket/socket in containers, it'll keep them
read-only ;-)
As `nix-daemon.service` does not make use of `ExecStop`, we prefer
to keep the socket up and available. This is important for machines
that run Nix-based services, such as automated build, test, and deploy
services, that expect the daemon socket to be available at all times.
See committed inline comment for further explanation.
The `substituters` option in `nix.settings` uses the order
of the substituters listed to define priority. Prior to https://github.com/NixOS/nixpkgs/pull/139075,
the corresponding option `binaryCaches` is declared in the `nix` namespace,
which is guaranteed to be merged last. However, the order of merging isn't
guaranteed in submodules. This cause definitions to be appended to the default
value instead of prepended, breaking backwards compatibility as reported in https://github.com/NixOS/nixpkgs/issues/158356.
The way this is addressed in the module system is with order priorities via
`mkOrder` and sorting definitions before merging. This PR restores the previous
behavior by setting a higher priority to the substituters option defined internally,
thus all definitions with default priority will be merged before it. This was chosen because
the `mkRenamedOption` function does not preserve order priority so users using legacy options do not have
precise control on placement.
This change should suffice for simple configuration, but further revision to the module system
is needed for to make various `mk*` functions aware of order priorities.
In #139075, mandatoryFeatures was removed from the generated
supportedFeatures, which breaks backward compatibility and is
different from what the description of supportedFeatures says.
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
The nix.daemonNiceLevel options allows for setting the nice level of the
Nix daemon process. On a modern Linux kernel with group scheduling the
nice level only affects threads relative to other threads in the same
task group (see sched(7)). Therefore this option has not the effect one
might expect.
The options daemonCPUSchedPolicy and daemonIOSchedClass are introduced
and the daemonIONiceLevel option renamed to daemonIOSchedPrority for
consistency. These options allow for more effective control over CPU
and I/O scheduling.
Instead of setting daemonNiceLevel to a high value to increase the
responsiveness of an interactive system during builds -- which would not
have the desired effect, as described above -- one could set both
daemonCPUSchedPolicy and daemonIOSchedClass to idle.
