Tilde ('~') does not expand to home of user actually running service start script about docker-systemctl-replacement

[manics]

I ran into a similar issue a few months ago- one of my systemd services was failing because some standard environment variables were missing.

I made my own fix manics@524ce62 but didn't have time to submit it as a PR, you've just reminded me about it.

The more general problem is the handling of environment variables. The systemd docs say only a fixed set should be defined. I did some investigation using this service file env-var-test.service to dump the variables for different users:

[Unit]
Description=xxx

[Service]
User=root
Type=forking
ExecStart=/bin/sh -c "(date; echo; /usr/bin/env) > /tmp/env-var-test.log"

User=root

SHELL=/bin/sh
USER=root
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
PWD=/
LANG=en_US.UTF-8
SHLVL=1
HOME=/root
LOGNAME=root
_=/usr/bin/env

User=vagrant

SHELL=/bin/bash
USER=vagrant
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
PWD=/
LANG=en_US.UTF-8
SHLVL=1
HOME=/home/vagrant
LOGNAME=vagrant
_=/usr/bin/env

This doesn't seem to match the systemd docs, so my above commit only added these

[gdraheim]

Oh well, that points back to the HISTORY of systemctl.py as a simple wrapper looking for ExecStart statements in the *.service files to be run. It was actually nice to inherit extra environment variables when checking services.

In any case, the environment variables referenced in the standard systemd documentation should be atleast on a value that matches expectations. So when $USER / $HOME should be overridden then it is the way to go.

[manics]

@gdraheim Do you want me to go ahead and open a PR with my fix once I've retested it? Or do you have some other solution in mind?

[TheTechsTech]

I had similar issues while compiling programs like freepbx under docker, I ended up doing something like this:

COPY systemctl.py /usr/bin/systemctl.py
RUN cp -f /usr/bin/systemctl /usr/bin/systemctl.original \
    && chmod +x /usr/bin/systemctl.py \
    && cp -f /usr/bin/systemctl.py /usr/bin/systemctl

I create the user, i needed an asterisk user

RUN export USER=xxxx && adduser xxxx -m -c "xxxx User" 

At this point i have my *.service files already copied over.
I use original for issues that come up.

RUN systemctl.original disable/enable

End build with:

RUN systemctl stop firewalld \
    && systemctl.original disable dbus firewalld \
    && (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
    systemd-tmpfiles-setup.service ] || rm -f $i; done); \
    rm -f /lib/systemd/system/multi-user.target.wants/*; \
    rm -f /lib/systemd/system/local-fs.target.wants/*; \
    rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
    rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
    rm -f /lib/systemd/system/basic.target.wants/*; \
    rm -f /lib/systemd/system/anaconda.target.wants/*; \
    rm -f /etc/dbus-1/system.d/*; \
    rm -f /etc/systemd/system/sockets.target.wants/*; 

And other things I found to cause issues and not usable in docker.

Start container up with.

ENTRYPOINT ["/usr/bin/systemctl","default","--init"]

[gdraheim]

@manics .... reviewing your patch, I see that you had completely replaced the env={} . Instead I would like to simply override the variables that are defined in the standard and where programs/services may expect them to be set.

Your link to the standard docs is extremely helpful for that. =>
https://www.freedesktop.org/software/systemd/man/systemd.exec.html#Environment%20variables%20in%20spawned%20processes

[gdraheim]

and please guys (include @techno-express ), do report such problems, there's no need to make up a workaround when it can get fixed in the upstream project. ;)

[gdraheim]

So, what do we have:

• $PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
• $LANG= ... actually setlocale() with the value from /etc/locale.conf
• $USER, $LOGNAME, $HOME, $SHELL .. only asserted when User= is present, so "postgres" is valid but "root" is not
• $INVOCATION_ID ... I have never heard of that, but a random() number seems easy
• $XDG_RUNTIME_DIR ... expected for user-mode only
• $MAINPID .... already done
• $MANAGERPID ... well, okay, but for non-init systemctl.py this is a volatile info
• $LISTEN_FDS, $LISTEN_PID, $LISTEN_FDNAMES ... I'd skip that as socket activation is not supported by systemctl.py
• $NOTIFY_SOCKET ... already done (for Type=notify services)
• $WATCHDOG_PID, $WATCHDOG_USEC ... keep-alive is not supported by systemctl.py
• $TERM ... "for units connected to a terminal", which is used for getty/rescue/reboot. We can keep the env value for that
• $JOURNAL_STREAM .. when "StandardError=journal" .. did not find any service to use it
• $SERVICE_RESULT ... already done (only valid in ExecStop / ExecStopPost)
• $EXIT_CODE, $EXIT_STATUS ... same here
  `
  So we are left with requirements for $PATH, $LANG, $INVOCATION_ID, $MANAGERPID ... and in set-user mode we have $USER, $LOGNAME, $HOME, $SHELL, $XDG_RUNTIME_DIR.

Probably we can also support $USER/$HOME for the default root-user as well.

[gdraheim]

I added some code, present in v1.4.2416, that may fix this problem.

I don't have testcase so far, so it is up to you to give it a try.

[gdraheim]

Already in release v1.4.2456