This lets users do sneaky things before systemd starts, and
permanently affect the environment in which systemd runs. For example,
we could start systemd in a non-default network namespace by setting
the systemdExecutable to a wrapper script containing:
#!/bin/sh
ip netns add virtual
touch /var/run/netns/physical
mount -o bind /proc/self/ns/net /var/run/netns/physical
exec ip netns exec virtual systemd
_note: the above example does literally work, but there are unresolved
problems with udev and dhcp._
In the current implementation, there's no possibility to modify the default
parameter for keepalive. This is a number that indicates how frequently
keepalive messages should be sent from the worker to the buildmaster,
expressed in seconds. The default (600) causes a message to be sent to
the buildmaster at least once every 10 minutes.
If the worker is behind a NAT box or stateful firewall, these messages
may help to keep the connection alive: some NAT boxes tend to forget about
a connection if it has not been used in a while. When this happens, the
buildmaster will think that the worker has disappeared, and builds will
time out. Meanwhile the worker will not realize than anything is wrong.
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.
Per upstream:
> libvirtd-tcp.socket - the unit file corresponding to the TCP 16509
> port for non-TLS remote access. This socket should not be configured
> to start on boot until the administrator has configured a suitable
> authentication mechanism.
Fixes error
Can't use an undefined value as an ARRAY reference at /nix/store/...-install-grub.pl line 642, <FILE> line 5.
with `/boot/grub/state` being:
```
grub
2.04
no
/dev/sda
/boot
```
I am not sure where the trailing empty line can come from; the script does not
seem to write it. In any case, now we handle that situation as well.
Further, ensure that `extraGrubInstallArgs` defaults to the empty array
if its key is not present in the `jsonState`.
For example, turns the error
cannot copy /nix/store/g24xsmmsz46hzi6whv7qwwn17myn3jfq-grub-2.04/share/grub/unicode.pf2 to /boot
into the more useful
cannot copy /nix/store/g24xsmmsz46hzi6whv7qwwn17myn3jfq-grub-2.04/share/grub/unicode.pf2 to /boot: Read-only file system
Useful for when you need to build grub modules into your grub kernel
to get a working boot, as shown in the added example.
To store this new value, we switch to more structural JSON approach.
Using one line per value to store in `/boot/grub/state` gets really messy when
the values are arrays, or even worse, can contain newlines (escaping would be
needed). Further, removing a value from the file would get extra messy
(empty lines we'd have to keep for backwards compatibility).
Thus, from now on we use JSON to store all values we'll need in the future.
Without this, systemd-boot does not add an EFI boot entry for itself.
The reason it worked before this fix is because it would fall back to
the default installed \EFI\BOOT\BOOTX64.EFI
