In some tests, e.g. -f nixos/release.nix tests.simple.x86_64-linux
we use noXlibs and qemu.ga. Now that output is tiny but to get it
a full qemu build is done, and some dependencies like gtk3 won't build
with noXlibs due to their dependencies being too stripped down.
Therefore let's reduce qemu features in noXlibs case.
The `sdlSupport = false;` part probably wasn't needed,
but I added it for consistency.
Turns out lot of software (including Chromium) use bundled fontconfig
so we either need to wrap every one of those, or re-introduce the global unversioned config.
The latter is easier but weakens hermetic configs. But perhaps those are not really worth the effort.
This allows disabling users.mutableUsers without configuring any
authentication mechanisms (passwords, authorized SSH keys) other than
Google OS Login.
This is required by (among others) Podman to run containers in rootless mode.
Other distributions such as Fedora and Ubuntu already set up these mappings.
The scheme with a start UID/GID offset starting at 100000 and increasing in 65536 increments is copied from Fedora.
Falling back to unversioned `/etc/fonts/conf.d` when versioned one does not exist
is problematic since it only occurs on non-NixOS systems and those are likely
to have a different version of fontconfig. When those versions use incompatible
elements in the config, apps using fontconfig will crash.
Instead, we are now falling back to the in-package `fonts.conf` file that loads
both the versioned global `conf.d` directory and the in-package `conf.d` since using
upstream settings on non-NixOS is preferable to not being able to use apps there.
In fact, we would not even need to link `fonts.conf`, as the in-package `fonts.conf`
will be always used unless someone creates the global one manually (the option is still
retained if one wants to write a custom NixOS module and to avoid unnecessary stat call on NixOS).
Additionally, since the `fonts.conf` will always load `conf.d` from the package, we no longer
need to install them to sytem `/etc` in the module. This needed some mucking with `50-user.conf`
which disables configs in user directories (a good thing IMO, NixOS module will turn it back on)
but otherwise, it is cleaner. The files are still prioritized by their name, regardless of their location.
See https://github.com/NixOS/nixpkgs/pull/73795#issuecomment-634370125 for more information.
This explanation was contained in the description of
security.initialRootPassword but got lost when it was deprecated
a long ago (f496c3c) and removed.
This option has been deprecated for a long time because is redundant
(users.users.root.initialHashedPassword exists).
Moreover, being of type string, it required to handle the special value
"!" separately, instead of using just `null`.
This explains the
# Allow the user to log in as root without a password.
users.users.root.initialHashedPassword = "";
that the NixOS installer live systems use in
`profiles/installation-device.nix`.
This fixes the output of "hostname --fqdn" (previously the domain name
was not appended). Additionally it's now possible to use the FQDN.
This works by unconditionally adding two entries to /etc/hosts:
127.0.0.1 localhost
::1 localhost
These are the first two entries and therefore gethostbyaddr() will
always resolve "127.0.0.1" and "::1" back to "localhost" [0].
This works because nscd (or rather the nss-files module) returns the
first matching row from /etc/hosts (and ignores the rest).
The FQDN and hostname entries are appended later to /etc/hosts, e.g.:
127.0.0.2 nixos-unstable.test.tld nixos-unstable
::1 nixos-unstable.test.tld nixos-unstable
Note: We use 127.0.0.2 here to follow nss-myhostname (systemd) as close
as possible. This has the advantage that 127.0.0.2 can be resolved back
to the FQDN but also the drawback that applications that only listen to
127.0.0.1 (and not additionally ::1) cannot be reached via the FQDN.
If you would like this to work you can use the following configuration:
```nix
networking.hosts."127.0.0.1" = [
"${config.networking.hostName}.${config.networking.domain}"
config.networking.hostName
];
```
Therefore gethostbyname() resolves "nixos-unstable" to the FQDN
(canonical name): "nixos-unstable.test.tld".
Advantages over the previous behaviour:
- The FQDN will now also be resolved correctly (the entry was missing).
- E.g. the command "hostname --fqdn" will now work as expected.
Drawbacks:
- Overrides entries form the DNS (an issue if e.g. $FQDN should resolve
to the public IP address instead of 127.0.0.1)
- Note: This was already partly an issue as there's an entry for
$HOSTNAME (without the domain part) that resolves to
127.0.1.1 (!= 127.0.0.1).
- Unknown (could potentially cause other unexpected issues, but special
care was taken).
[0]: Some applications do apparently depend on this behaviour (see
c578924) and this is typically the expected behaviour.
Co-authored-by: Florian Klink <flokli@flokli.de>
Instead of hardcoding all nss modules that are added into nsswitch,
there are now options exposed.
This allows users to add own nss modules (I had this issue with
winbindd, for example).
Also, nss modules could be moved to their NixOS modules which would
make the nsswitch module slimmer.
As the lists are now handled by the modules system, we can use mkOrder
to ensure a proper order as well as mkForce to override one specific
database type instead of the entire file.
