v2:
- add example files to EXTRA_DIST
v3:
- rework for the new scheme where nothing is written to disk
v4:
- use separate dirs for system and user env generators
Environment file generators are a lot like unit file generators, but not
exactly:
1. environment file generators are run for each manager instance, and their
output is (or at least can be) individualized.
The generators themselves are system-wide, the same for all users.
2. environment file generators are run sequentially, in priority order.
Thus, the lifetime of those files is tied to lifecycle of the manager
instance. Because generators are run sequentially, later generators can use or
modify the output of earlier generators.
Each generator is run with no arguments, and the whole state is stored in the
environment variables. The generator can echo a set of variable assignments to
standard output:
VAR_A=something
VAR_B=something else
This output is parsed, and the next and subsequent generators run with those
updated variables in the environment. After the last generator is done, the
environment that the manager itself exports is updated.
Each generator must return 0, otherwise the output is ignored.
The generators in */user-env-generator are for the user session managers,
including root, and the ones in */system-env-generator are for pid1.
strv_env_replace was calling env_match(), which in effect allowed multiple
values for the same key to be inserted into the environment block. That's
pointless, because APIs to access variables only return a single value (the
latest entry), so it's better to keep the block clean, i.e. with just a single
entry for each key.
Add a new helper function that simply tests if the part before '=' is equal in
two strings and use that in strv_env_replace.
In load_env_file_push, use strv_env_replace to immediately replace the previous
assignment with a matching name.
Afaict, none of the callers are materially affected by this change, but it
seems like some pointless work was being done, if the same value was set
multiple times. We'd go through parsing and assigning the value for each
entry. With this change, we handle just the last one.
This protocol is generally useful, we might just as well reuse it for the
env. generators.
The implementation is changed a bit: instead of making a new strv and freeing
the old one, just mutate the original. This is much faster with larger arrays,
while in fact atomicity is preserved, since we only either insert the new
entry or not, without being in inconsistent state.
v2:
- fix confusion with return value
The output of processes can be gathered, and passed back to the callee.
(This commit just implements the basic functionality and tests.)
After the preparation in previous commits, the change in functionality is
relatively simple. For coding convenience, alarm is prepared *before* any
children are executed, and not before. This shouldn't matter usually, since
just forking of the children should be pretty quick. One could also argue that
this is more correct, because we will also catch the case when (for whatever
reason), forking itself is slow.
Three callback functions and three levels of serialization are used:
- from individual generator processes to the generator forker
- from the forker back to the main process
- deserialization in the main process
v2:
- replace an structure with an indexed array of callbacks
There is a slight change in behaviour: the user manager for root will create a
temporary file in /run/systemd, not /tmp. I don't think this matters, but
simplifies implementation.
Essentially the same logic as in conf_files_list() was independently implemented in
do_execute(). With previous commit, do_execute() can just call conf_files_list() to
get a list of executable paths.
5dd11ab5f3 did a similar change for conf_files_list_strv().
Here we do the same for conf_files_list() and conf_files_list_nulstr().
No change for existing users. Tests are added.
After generating the template name we can shortcut things and just call
unit_file_find_dirs() from inside itself, just with the new name and
save a good number of duplicate lines.
Let's clarify that RestrictAddressFamilies= and MemoryDenyWriteExecute=
are only fully effective if non-native system call architectures are
disabled, since they otherwise may be used to circumvent the filters, as
the filters aren't equally effective on all ABIs.
Fixes: #5277
Or actually, try to to do the right thing depending on what is
available:
- If we know $HOME from User=, then use that.
- If the UID for the service is 0, hardcode that WorkingDirectory=~ means WorkingDirectory=/root
- In any other case (which will be the unprivileged --user case), use
get_home_dir() to find the $HOME of the user we are running as.
- Otherwise fail.
Fixes: #5246#5124
We should try to keep the unbreakable lines below 80 columns.
It's not always possible of course.
Also, use the dl.fp.o alias instead of a specific mirror.
There was a missing dependency and one with the wrong type. Additionally, refer
to DefaultDependencies= once instead of twice, without a vague reference in the
first one that doesn't mention that the value matters.
Fixes#5226.
Add a bit of code that tries to get the right parameter order in place
for some of the better known architectures, and skips
restrict_namespaces for other archs.
This also bypasses the test on archs where we don't know the right
order.
In this case I didn't bother with testing the case where no filter is
applied, since that is hopefully just an issue for now, as there's
nothing stopping us from supporting more archs, we just need to know
which order is right.
Fixes: #5241
The code make the following assertion: when freeing a event loop object
(usually it's done after exiting from the main event loop), no signal events
are still queued and are pending.
This assertion can be found in event_unmask_signal_data() with
"assert(!d->current);" assertion.
It appears that this assertion can be wrong at least in a specific case
described below.
Consider the following example which is inspired from udev: a process defines 3
source events: 2 are created by sd_event_add_signal() and 1 is created by
sd_event_add_post().
1. the process receives the 2 signals consecutively so that signal 'A' source
event is queued and pending. Consequently the post source event is also
queued and pending. This is done by sd_event_wait().
2. The callback for signal 'A' is called by sd_event_dispatch().
3. The next call to sd_event_wait() will queue signal 'B' source event.
4. The callback for the post source event is called and calls sd_event_exit().
5. the event loop is exited.
6. freeing the event loop object will lead to the assertion failure in
event_unmask_signal_data().
This patch simply removes this assertion as it doesn't seem to be a
bug if the signal data still reference a signal source at this point.
