ENOENT is easily confused with the file that we're working on not being
present, e.g. when the file contains %o or something else that requires
os-release to be present. Let's use -EUNATCH instead to reduce that chances of
confusion if the context of the error is lost.
And once we have pinpointed the reason, let's provide a proper error message:
+ build/systemctl --root=/tmp/systemctl-test.TO7Mcb enable some-some-link6@.socket
/tmp/systemctl-test.TO7Mcb/etc/systemd/system/some-some-link6@.socket: Failed to resolve alias "target@A:%A.socket": Protocol driver not attached
Failed to enable unit, cannot resolve specifiers in "target@A:%A.socket".
In systemd.unit we document that unset fields resolve to "". But we didn't
directly test this, so let's do that. Also, we return -ENOENT if the file
is missing, which we didn't document or test.
We didn't actually say that keys should not be repeated. At least the
examples in docs (both python and shell) would do that, and any simple
parser that builds a dictionary would most likely behave the same way.
But let's document this expectation, but also say how to deal with malformed
files.
The test for the variable is added in test-systemctl-enable because there we
can do it almost for free, and the variable is most likely to be used with
'systemctl enable --root' anyway.
This test has overlap with test-install-root, but it tests things at a
different level, so I think it's useful to add. It immediately shows various
bugs which will be fixed in later patches.
When we are printing a valid unit name, quoting isn't necessary, because
unit names cannot contain whitespace or other confusing characters. In particular
if the unit name is prefixed by " unit " or something else that clearly
identifies the string as a unit name, quoting would just add unnecessary
noise. But when we're printing paths or invalid names, it's better to add
quotes for clarity.
We save a few lines, but the important thing is that we don't have two
different implementations with slightly different rules used for enablement
and loading. Fixes#22000.
Tested with:
- the report in #22000, it now says:
$ SYSTEMD_LOG_LEVEL=debug systemctl --root=/ enable test.service
Suspicious symlink /etc/systemd/system/test.service→/etc/systemd/system/myown.d/test.service, treating as alias.
unit_file_resolve_symlink: self-alias: /etc/systemd/system/test.service → test.service, ignoring.
running_in_chroot(): Permission denied
Suspicious symlink /etc/systemd/system/test.service→/etc/systemd/system/myown.d/test.service, treating as alias.
unit_file_resolve_symlink: self-alias: /etc/systemd/system/test.service → test.service, ignoring.
Failed to enable unit, refusing to operate on linked unit file test.service
- a symlink to /dev/null:
...
unit_file_resolve_symlink: linked unit file: /etc/systemd/system/test3.service → /dev/null
Failed to enable unit, unit /etc/systemd/system/test3.service is masked.
- the same from the host:
...
unit_file_resolve_symlink: linked unit file: /var/lib/machines/rawhide/etc/systemd/system/test3.service → /var/lib/machines/rawhide/dev/null
Failed to enable unit, unit /var/lib/machines/rawhide/etc/systemd/system/test3.service is masked.
- through the manager:
$ sudo systemctl enable test.service
Failed to enable unit: Refusing to operate on alias name or linked unit file: test.service
$ sudo systemctl enable test3.service
Failed to enable unit: Unit file /etc/systemd/system/test3.service is masked.
As seen in the first example, the warning is repeated. This is because we call
the lookup logic twice: first for sysv-compat, and then again for real. I think
that since this is only for broken setups, and when sysv-compat is enabled, and
in an infrequent manual operation, at debug level, this is OK.
The old logs used __func__, but this doesn't make sense now, because the
low-level function will be used in other places. So those are adjusted to be
more generic.
Same idea as 03677889f0.
No functional change intended. The type of the iterator is generally changed to
be 'const char*' instead of 'char*'. Despite the type commonly used, modifying
the string was not allowed.
I adjusted the naming of some short variables for clarity and reduced the scope
of some variable declarations in code that was being touched anyway.
When we do mkdir, we should just use 0o777 and let the umask take care of the
rest. Specifying an explicit mode is inappropriate. And when touching the code,
let's replace black madness with normal python style.
To notify user of kill events from systemd-oomd we now use
`SERVICE_FAILURE_OOM_KILL` as the failure result.
`unit_check_oomd_kill` now calls `notify_cgroup_oom` to
update the service result to `oom-kill`.
We add a new xattr `user.oomd_ooms` to keep track of the OOM kills
initiated by systemd-oomd, this helps us resolve a race between sending
SIGKILL to processes and checking for OOM kill status from the xattr.
Related to: #20649
When sorting paths it actually matters to use the right comparison
function. Example:
```
a/x
a-b/y
a_/z
```
I think people would probably expect this:
```
a/x
a-b/y
a_a/z
```
but if you use strcmp() instead of path_compare() you'd instead get:
```
a-b/y
a/x
a_a/z
```
That's because `/` is between `-` and `a` in the ascii table. I think
that's quite confusing, and we shouldn#t order that way hence.
As discussed: https://github.com/systemd/systemd/pull/22662#discussion_r831174776
