Let's rework the D-Bus APIs GetImageOSRelease() to use the new internal
metadata API, to query what it needs to know. Augment it with
GetImageHostname(), GetImageMachineID(), GetImageMachineInfo(), that
expose the other new APIS.
This adds an internal API that permits querying metadata from any type
of image, including both subvol/dir images, and raw/block images. In the
latter case we use the new dissection API we just added.
We focus on four kinds of metadata:
1. /etc/hostname
2. /etc/machine-id
3. /etc/machine-info
4. /etc/os-release or /usr/lib/os-release
This makes dissected images nicely self-contained as we can figure out
what they are just by dissecting them.
First of all, let's rename it to read_etc_hostname(), to make clearer
what kind of configuration it actually reads: the file format defined in
/etc/hostname and nothing else.
Secondly: let's port this to use read_line(), i.e. the new way to read
lines from a file in a safe, bounded way.
Thirdly: let's strip leading/trailing whitespace from what we are
reading. Given that we are already pretty lenient what we read (comments
and empty lines), let's be permissive regarding whitespace too.
Fourthly: let's actually validate the hostname when reading it. So far
we tried to make it valid, but that's not always possible (for example,
we can't make an empty hostname valid, ever).
At some point before gcc-7 was released, -Wimplicit-fallthrough=3 was included
in -Wextra. The documentation for gcc-7.2.1-2.fc27.x86_64 still says that, but
empirical testing shows that it's not. The documentation also misstates that
-Wimplicit-fallthrough is equivalent to -Wimplicit-fallthrough=3.
Let's add -Wimplicit-fallthrough=3 explicitly to get the warnings if we regress.
Prompted by #7389.
This little new command can parse, validate, normalize calendar events,
and calculate when they will elapse next. This should be useful for
anyone writing calendar events and who'd like to validate the expression
before running them as timer units.
It is not necessary to label as loaded to a swap unit when neither of
corresponding unit file nor entry in /proc/swap does not exist.
This makes swap_load() to fail such a case.
Partially fixes#7370.
It is not necessary to label as loaded to automount unit when its unit
file does not exist. So, let's make automount_load() to fail when the
unit file does not exist.
Partially fixes#7370.
So far I avoided adding license headers to meson files, but they are pretty
big and important and should carry license headers like everything else.
I added my own copyright, even though other people modified those files too.
But this is mostly symbolic, so I hope that's OK.
We just load the same kernel that would be loaded by default by sd-boot, with
the same options. Changing the kernel or initramfs or options is left for
later.
Now we will refuse to continue if loading fails. This makes 'systemctl kexec'
more predictable: it will not fall back to normal reboot if the kernel is
not loaded.
