%c and %r rely on settings made in the unit files themselves and hence resolve
to different values depending on whether they are used before or after Slice=.
Let's simply deprecate them and drop them from the documentation, as that's not
really possible to fix. Moreover they are actually redundant, as the same
information may always be queried from /proc/self/cgroup and /proc/1/cgroup.
(Accurately speaking, %R is actually not broken like this as it is constant.
However, let's remove all cgroup-related specifiers at once, as it is also
redundant, and doesn't really make much sense alone.)
Various things don't work when we're running in a user namespace, but it's
pretty hard to reliably detect if that is true.
A function is added which looks at /proc/self/uid_map and returns false
if the default "0 0 UINT32_MAX" is found, and true if it finds anything else.
This misses the case where an 1:1 mapping with the full range was used, but
I don't know how to distinguish this case.
'systemd-detect-virt --private-users' is very similar to
'systemd-detect-virt --chroot', but we check for a user namespace instead.
Let's avoid the overly abbreviated "cgroups" terminology. Let's instead write:
"Linux Control Groups (cgroups)" is the long form wherever the term is
introduced in prose. Use "control groups" in the short form wherever the term
is used within brief explanations.
Follow-up to: #4381
In certain situations drop-ins in /usr/lib/ are useful, for example when one package
wants to modify the behaviour of another package, or the vendor wants to tweak some
upstream unit without patching.
Drop-ins in /run are useful for testing, and may also be created by systemd itself.
Follow-up for the discussion in #2103.
Also update the description of drop-ins in systemd.unit(5) to say that .d
directories, not .conf files, are in /etc/system/system, /run/systemd/system,
etc.
The man pages didn't ever mention that symlinks to units can be created, and what
exactly this means. Fix that omission, and disallow presets on alias names.
Let's move the enforcement of the per-unit start limit from unit.c into the
type-specific files again. For unit types that know a concept of "result" codes
this allows us to hook up the start limit condition to it with an explicit
result code. Also, this makes sure that the state checks in clal like
service_start() may be done before the start limit is checked, as the start
limit really should be checked last, right before everything has been verified
to be in order.
The generic start limit logic is left in unit.c, but the invocation of it is
moved into the per-type files, in the various xyz_start() functions, so that
they may place the check at the right location.
Note that this change drops the enforcement entirely from device, slice, target
and scope units, since these unit types generally may not fail activation, or
may only be activated a single time. This is also documented now.
Note that restores the "start-limit-hit" result code that existed before
6bf0f408e4 already in the service code. However,
it's not introduced for all units that have a result code concept.
Fixes#3166.
We generally follow the rule that for time settings we suffix the setting name
with "Sec" to indicate the default unit if none is specified. The only
exception was the rate limiting interval settings. Fix this, and keep the old
names for compatibility.
Do the same for journald's RateLimitInterval= setting
With #2564 unit start rate limiting was moved from after the condition checks
are to before they are made, in an attempt to fix#2467. This however resulted
in #2684. However, with a previous commit a concept of per socket unit trigger
rate limiting has been added, to fix#2467 more comprehensively, hence the
start limit can be moved after the condition checks again, thus fixing #2684.
Fixes: #2684
Let's make this more digestable to read by making the list of documented unit
file paths a bit shorter.
Specifically, let's drop references to $XDG_CONFIG_HOME and $XDG_DATA_HOME, as
their default values are listed too already. Given that the fact that the XDG
basedir spec makes these paths configurable is probably not a strong point of
the spec, let's drop the reference to the env vars, and keep only the literal,
default paths for them in the list. Of course, we do support the full XDG
basedir spec in this regard, but it's one thing to implement it and another one
to recommend it by documenting it.
Replace "$HOME" by "~", because UNIX.
This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section
into the [Unit] section of unit files, and thus support it in all unit types, not just in services.
This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that
repeated start-up failure due to failed conditions is also considered for the start limit logic.
For compatibility the four options may also be configured in the [Service] section still, but we only document them in
their new section [Unit].
This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express
more clearly what it is about, after all it's only triggered through the start limit being hit.
Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike.
Fixes: #2467
As discussed at systemd.conf 2015 and on also raised on the ML:
http://lists.freedesktop.org/archives/systemd-devel/2015-November/034880.html
This removes the two XyzOverridable= unit dependencies, that were
basically never used, and do not enhance user experience in any way.
Most folks looking for the functionality this provides probably opt for
the "ignore-dependencies" job mode, and that's probably a good idea.
Hence, let's simplify systemd's dependency engine and remove these two
dependency types (and their inverses).
The unit file parser and the dbus property parser will now redirect
the settings/properties to result in an equivalent non-overridable
dependency. In the case of the unit file parser we generate a warning,
to inform the user.
The dbus properties for this unit type stay available on the unit
objects, but they are now hidden from usual introspection and will
always return the empty list when queried.
This should provide enough compatibility for the few unit files that
actually ever made use of this.
Previously, the %u, %U, %s and %h specifiers would resolve to the user
name, numeric user ID, shell and home directory of the user configured
in the User= setting of a unit file, or the user of the manager instance
if no User= setting was configured. That at least was the theory. In
real-life this was not ever actually useful:
- For the systemd --user instance it made no sense to ever set User=,
since the instance runs in user context after all, and hence the
privileges to change user IDs don't even exist. The four specifiers
were actually not useful at all in this case.
- For the systemd --system instance we did not allow any resolving that
would require NSS. Hence, %s and %h were not supported, unless
User=root was set, in which case they would be hardcoded to /bin/sh
and /root, to avoid NSS. Then, %u would actually resolve to whatever
was set with User=, but %U would only resolve to the numeric UID of
that setting if the User= was specified in numeric form, or happened
to be root (in which case 0 was hardcoded as mapping). Two of the
specifiers are entirely useless in this case, one is realistically
also useless, and one is pretty pointless.
- Resolving of these settings would only happen if User= was actually
set *before* the specifiers where resolved. This behaviour was
undocumented and is really ugly, as specifiers should actually be
considered something that applies to the whole file equally,
independently of order...
With this change, %u, %U, %s and %h are drastically simplified: they now
always refer to the user that is running the service instance, and the
user configured in the unit file is irrelevant. For the system instance
of systemd this means they always resolve to "root", "0", "/bin/sh" and
"/root", thus avoiding NSS. For the user instance, to the data for the
specific user.
The new behaviour is identical to the old behaviour in all --user cases
and for all units that have no User= set (or set to "0" or "root").
For all units ensure there's an "Automatic Dependencies" section in the
man page, and explain which dependencies are automatically added in all
cases, and which ones are added on top if DefaultDependencies=yes is
set.
This is also done for systemd.exec(5), systemd.resource-control(5) and
systemd.unit(5) as these pages describe common behaviour of various unit
types.
Snapshots were never useful or used for anything. Many systemd
developers that I spoke to at systemd.conf2015, didn't even know they
existed, so it is fairly safe to assume that this type can be deleted
without harm.
The fundamental problem with snapshots is that the state of the system
is dynamic, devices come and go, users log in and out, timers fire...
and restoring all units to some state from the past would "undo"
those changes, which isn't really possible.
Tested by creating a snapshot, running the new binary, and checking
that the transition did not cause errors, and the snapshot is gone,
and snapshots cannot be created anymore.
New systemctl says:
Unknown operation snapshot.
Old systemctl says:
Failed to create snapshot: Support for snapshots has been removed.
IgnoreOnSnaphost settings are warned about and ignored:
Support for option IgnoreOnSnapshot= has been removed and it is ignored
http://lists.freedesktop.org/archives/systemd-devel/2015-November/034872.html
Add a new config directive called NetClass= to CGroup enabled units.
Allowed values are positive numbers for fix assignments and "auto" for
picking a free value automatically, for which we need to keep track of
dynamically assigned net class IDs of units. Introduce a hash table for
this, and also record the last ID that was given out, so the allocator
can start its search for the next 'hole' from there. This could
eventually be optimized with something like an irb.
The class IDs up to 65536 are considered reserved and won't be
assigned automatically by systemd. This barrier can be made a config
directive in the future.
Values set in unit files are stored in the CGroupContext of the
unit and considered read-only. The actually assigned number (which
may have been chosen dynamically) is stored in the unit itself and
is guaranteed to remain stable as long as the unit is active.
In the CGroup controller, set the configured CGroup net class to
net_cls.classid. Multiple unit may share the same net class ID,
and those which do are linked together.
.nspawn fiels are simple settings files that may accompany container
images and directories and contain settings otherwise passed on the
nspawn command line. This provides an efficient way to attach execution
data directly to containers.
This did not really work out as we had hoped. Trying to do this upstream
introduced several problems that probably makes it better suited as a
downstream patch after all. At any rate, it is not releaseable in the
current state, so we at least need to revert this before the release.
* by adjusting the path to binaries, but not do the same thing to the
search path we end up with inconsistent man-pages. Adjusting the search
path too would be quite messy, and it is not at all obvious that this is
worth the effort, but at any rate it would have to be done before we
could ship this.
* this means that distributed man-pages does not make sense as they depend
on config options, and for better or worse we are still distributing
man pages, so that is something that definitely needs sorting out before
we could ship with this patch.
* we have long held that split-usr is only minimally supported in order
to boot, and something we hope will eventually go away. So before we start
adding even more magic/effort in order to make this work nicely, we should
probably question if it makes sense at all.
In particular, use /lib/systemd instead of /usr/lib/systemd in distributions
like Debian which still have not adopted a /usr merge setup.
Use XML entities from man/custom-entities.ent to replace configured paths while
doing XSLT processing of the original XML files. There was precedent of some
files (such as systemd.generator.xml) which were already using this approach.
This addresses most of the (manual) fixes from this patch:
http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/patches/Fix-paths-in-man-pages.patch?h=experimental-220
The idea of using generic XML entities was presented here:
http://lists.freedesktop.org/archives/systemd-devel/2015-May/032240.html
This patch solves almost all the issues, with the exception of:
- Path to /bin/mount and /bin/umount.
- Generic statements about preference of /lib over /etc.
These will be handled separately by follow up patches.
Tested:
- With default configure settings, ran "make install" to two separate
directories and compared the output to confirm they matched exactly.
- Used a set of configure flags including $CONFFLAGS from Debian:
http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/rules
Installed the tree and confirmed the paths use /lib/systemd instead of
/usr/lib/systemd and that no other unexpected differences exist.
- Confirmed that `make distcheck` still passes.
Lennart Poettering