This new mode copies resources provided by the client, so that they
remain available for inspect/detach even if the original images are
deleted, but symlinks the profile as that is owned by the OS, so that
updates are automatically applied.
fresh otherwise
Currently, exec_setup_credential() always rewrite all credentials
upon exec_invoke(), i.e. invocation of each ExecCommand, and within
a single tmpfs instance. This is problematic though:
* When writing each tmp cred file, we essentially double the size
of the credential. Therefore, if one cred is bigger than half
of CREDENTIALS_TOTAL_SIZE_MAX, confusing ENOSPC occurs (see also
https://github.com/systemd/systemd/pull/24734#issuecomment-1925440546)
* Credential is a unit-wide thing and thus should not change
during the whole lifetime of main process. However, if e.g.
a on-disk credential or SetCredential= in unit file
changes between ExecStart= and ExecStartPost=,
the credentials are overwritten when the latter gets to run,
and the already-running main process is suddenly seeing
completely different creds.
So, let's try to reuse final cred dir if the main process has started
and the tmpfs has been populated, so that the creds used is stable
across all ExecStart= and ExecStartPost=-s. We still want to retain
the ability of updating creds through ExecStartPre= though, therefore
we forcibly use a fresh cred dir for those. 'Fresh' means to actually
unmount the old tmpfs first, so the first problem goes away, too.
It's easy to add. Let's do so.
This only covers record lookups, i.e. with the --type= switch.
The higher level lookups are not covered, I opted instead to print a
message there to use --type= instead.
I am a bit reluctant to defining a new JSON format for the high-level
lookups, hence I figured for now a helpful error is good enough, that
points people to the right use.
Fixes: #29755
Previously, unit_{start,stop,reload} would call the low-level cgroup
unfreeze function whenever a unit was started, stopped, or reloaded. It
did so with no error checking. This call would ultimately recurse up the
cgroup tree, and unfreeze all the parent cgroups of the unit, unless an
error occurred (in which case I have no idea what would happen...)
After the freeze/thaw rework in a previous commit, this can no longer
work. If we recursively thaw the parent cgroups of the unit, there may
be sibling units marked as PARENT_FROZEN which will no longer actually
have frozen parents. Fixing this is a lot more complicated than simply
disallowing start/stop/reload on a frozen unit
Fixes https://github.com/systemd/systemd/issues/15849
This commit overhauls the way freeze/thaw works recursively:
First, it introduces new FreezerActions that are like the existing
FREEZE and THAW but indicate that the action was initiated by a parent
unit. We also refactored the code to pass these FreezerActions through
the whole call stack so that we can make use of them. FreezerState was
extended similarly, to be able to differentiate between a unit that's
frozen manually and a unit that's frozen because a parent is frozen.
Next, slices were changed to check recursively that all their child
units can be frozen before it attempts to freeze them. This is different
from the previous behavior, that would just check if the unit's type
supported freezing at all. This cleans up the code, and also ensures
that the behavior of slices corresponds to the unit's actual ability
to be frozen
Next, we make it so that if you FREEZE a slice, it'll PARENT_FREEZE
all of its children. Similarly, if you THAW a slice it will PARENT_THAW
its children.
Finally, we use the new states available to us to refactor the code
that actually does the cgroup freezing. The code now looks at the unit's
existing freezer state and the action being requested, and decides what
next state is most appropriate. Then it puts the unit in that state.
For instance, a RUNNING unit with a request to PARENT_FREEZE will
put the unit into the PARENT_FREEZING state. As another example, a
FROZEN unit who's parent is also FROZEN will transition to
PARENT_FROZEN in response to a request to THAW.
Fixes https://github.com/systemd/systemd/issues/30640
Fixes https://github.com/systemd/systemd/issues/15850
It never worked, but the fail was masked by missing set -e, see the
previous commit.
Also, throw env into the test container and dump the environment on
container start, to make potential failures easier to debug.
Previously, path units would remain in the running state while their
target unit is deactivating. This left a window of time where the target
unit is no longer operational (i.e. it is busy deactivating/cleaning
up/etc) but the path unit would continue to ignore inotify events. In
short: any inotify event that occurs while the target unit deactivates
would be completely lost.
With this commit, the path will go back into a waiting state when the
target unit starts deactivating. This means that any inotify event that
occurs while the target unit deactivates will queue a start job.
With newer versions of AppArmor, unprivileged user namespace creation
may be restricted by default, in which case user manager instances will
not be able to apply PrivateUsers=yes, which is implied by
PrivateTmp=yes in this systemd-run invocation.
With newer versions of AppArmor, unprivileged user namespace creation
may be restricted by default, in which case user manager instances will
not be able to apply PrivateUsers=yes (or the settings which require it).
This can be tested with the kernel.apparmor_restrict_unprivileged_userns
sysctl.
Mike Yuan
Yu Watanabe
Luca Boccassi
Lennart Poettering
Franck Bui
Vladimir Stoiakin
Frantisek Sumsal
Gabríel Arthúr Pétursson
Adrian Vovk
Daan De Meyer
Nick Rosbrook
Ronan Pigott
David Tardon