I keep running "systemd-run -t /bin/bash" to quickly get a shell running
in service context. I suspect I am not the only one, hence let's add a
shortcut for it. While we are at it, let's make it smarter, and
automatically inherit the $SHELL of the invoking user as well as the
working directory, and let's imply --pty. --shell (or -S) is hence
equivalent to "-t -d $SHELL".
I find myself testing service management quite often with "systemd-run
-t /bin/bash". For that it is handy if the invoked shell would use the
working directory I am currently in. Hence introduce a shorthand for
that:
$ systemd-run -dt /bin/bash
This will automatically insert a WorkingDirectory= property into the
transient service, pointing to the working directory of the caller.
And while we are at it, let's rearrange and extend the Type=
documentation a bit. Let's make it an itemized list, and let's add a
paragraph explaining which type best to use.
Docbook styles required those to be present, even though the templates that we
use did not show those names anywhere. But something changed semi-recently (I
would suspect docbook templates, but there was only a minor version bump in
recent years, and the changelog does not suggest anything related), and builds
now work without those entries. Let's drop this dead weight.
Tested with F26-F29, debian unstable.
$ perl -i -0pe 's/\s*<authorgroup>.*<.authorgroup>//gms' man/*xml
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Systemd services are permitted to be scripts, as well as binary
executables.
The same also applies to the underlying /sbin/mount and /sbin/swapon.
It is not necessary for the user to consider what type of program file
these are. Nor is it necessary with systemd-nspawn, to distinguish between
init as a "binary" v.s. a user-specified "program".
Also fix a couple of grammar nits in the modified sentences.
This option is likely to be very useful for systemd-run invocations,
hence let's add a shortcut for it.
With this new concepts it's now very easy to put together systemd-run
invocations that leave zero artifacts in the system, including when they
fail.
In this mode, we'll directly connect stdin/stdout/stderr of the invoked
service with whatever systemd-run itself is invoked on. This allows
inclusion of "systemd-run" commands in shell pipelines, as unlike
"--pty" this means EOF of stdin/stdout/stderr are propagated
independently.
If --pty and --pipe are combined systemd-run will automatically pick the
right choice for the context it is invoked in, i.e. --pty when invoked
on a TTY, and --pipe otherwise.
This adds a brief explanation, suggesting the use of "systemd-run -M" to
acquire exit status/code information for the invoked process.
My original plan was to propagate the exit code/status in "machinectl
shell" too, but this would mean we'd have to actively watch the shell's
runtime status, and thus would need full, highly privileged and
continious access to the container's system manager, the way
"systemd-run" does it. This would be quite a departure from the
simplistic, low-priviliged OpenShell() bus call implementation of the
current code, that really just acquires a PTY device with a shell
connected.
Moreover it would blur the lines between the two commands even further,
which I think is not desirable. Hence, from now on:
"machinectl shell" is the full-session, interactive shell for human
users
"systemd-run -M …" is the low-level tool, that supports
on-interactive mode, and is more configurable and suitable for
streaming.
Fixes: #4215
This adds "systemd-mount" which is for transient mount and automount units what
"systemd-run" is for transient service, scope and timer units.
The tool allows establishing mounts and automounts during runtime. It is very
similar to the usual /bin/mount commands, but can pull in additional
dependenices on access (for example, it pulls in fsck automatically), an take
benefit of the automount logic.
This tool is particularly useful for mount removable file systems (such as USB
sticks), as the automount logic (together with automatic unmount-on-idle), as
well as automatic fsck on first access ensure that the removable file system
has a high chance to remain in a fully clean state even when it is unplugged
abruptly, and returns to a clean state on the next re-plug.
This is a follow-up for #2471, as it adds a simple client-side for the
transient automount logic added in that PR.
In later work it might make sense to invoke this tool automatically from udev
rules in order to implement a simpler and safer version of removable media
management á la udisks.
