Those lists were partially wrong and partially outdated. We should generate
this document automatically, but let's revisit this topic after the conversion
to sphinx. For now, as a stop-gap solution, I generated the lists from
the new 'systemd-analyze transient-settings' command.
Related to https://github.com/systemd/systemd/pull/37641.
The name "transient settings" was used in docs/TRANSIENT-SETTINGS.md.
Using "setting" helps distinguish this from D-Bus "properties", which are
a much larger set, partially overlapping.
bus_append_unit_property() and associated functions accept a long list of
properties. But the specific names are only available through code. But it is
useful to be able to know the specific list of properties that is supported, in
particular for shell completions. Thus, add a way to list the properties that
are supported by the code.
In the future we could also turn this into a test for the documentation. For
various reasons, the list of properties listed in the docs is a partially
overlapping set. E.g. for service type, the pull request
https://github.com/systemd/systemd/pull/37661 creates a list with 212 entries,
and this code generates 7 entries less and 184 more. I didn't check all the
differences, but in the few cases I did, the list generated here was actually
correctly supported by 'systemd-run -p'.
A smoke test is added.
This is a separate commit because the parent commit is supposed to be
backward compatible, i.e. the tests must pass with both the bogus ProtectHostnameEx
name and ProtectHostname.
A test is added for ProtectHostnameEx to verify that it is still accepted
for backward compat.
As with grandparent commit for ImportCredentialEx=, the whole series of commits
that extended ProtectHostname was confused (6746f28854,
cf48bde7ae, e76fcd0e40),
because it added ProtectHostnameEx in places where parsing of ProtectHostname
should be have been extended.
Accept ProtectHostname=… with the new extended syntax, keep accepting
ProtectHostnameEx=… for compat with release v257. Prefer sending ProtectHostname.
Partially resolves https://github.com/systemd/systemd/issues/37174.
We add D-Bus properties like "*Ex" because we cannot change the D-Bus property
type without breaking backward comapatibility. But those names are only for
D-Bus, not for config file stanzas or the command-line parser. There, we can
change the type, or in other words, there is no type, just a free-form string
whose interpretation we can extend or change. Commit
831f208783 that added ProtectHostnameEx was
confused, because it added ImportCredentialEx in places where parsing of
ImportCredential should be have been extended.
On D-Bus, we send ImportCrednential in preference, and ImportCredentialEx only
when required. This way we send less bytes on the wire and support older
systems that don't understand the new property.
Partially resolves https://github.com/systemd/systemd/issues/37174.
