From 287419c119ef961db487a281162ab037eba70c61 Mon Sep 17 00:00:00 2001
From: Alban Crequy <alban.crequy@gmail.com>
Date: Fri, 18 Sep 2015 13:37:34 +0200
Subject: containers: systemd exits with non-zero code

When a systemd service running in a container exits with a non-zero
code, it can be useful to terminate the container immediately and get
the exit code back to the host, when systemd-nspawn returns. This was
not possible to do. This patch adds the following to make it possible:

- Add a read-only "ExitCode" property on PID 1's "Manager" bus object.
  By default, it is 0 so the behaviour stays the same as previously.
- Add a method "SetExitCode" on the same object. The method fails when
  called on baremetal: it is only allowed in containers or in user
  session.
- Add support in systemctl to call "systemctl exit 42". It reuses the
  existing code for user session.
- Add exit.target and systemd-exit.service to the system instance.
- Change main() to actually call systemd-shutdown to exit() with the
  correct value.
- Add verb 'exit' in systemd-shutdown with parameter --exit-code
- Update systemctl manpage.

I used the following to test it:

| $ sudo rkt --debug --insecure-skip-verify run \
|            --mds-register=false --local docker://busybox \
|            --exec=/bin/chroot -- /proc/1/root \
|            systemctl --force exit 42
| ...
| Container rkt-895a0cba-5c66-4fa5-831c-e3f8ddc5810d failed with error code 42.
| $ echo $?
| 42

Fixes https://github.com/systemd/systemd/issues/1290
---
 man/systemctl.xml | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

(limited to 'man/systemctl.xml')

diff --git a/man/systemctl.xml b/man/systemctl.xml
index d8d433e4d3..c1359d1678 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -1633,13 +1633,17 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
         </varlistentry>
 
         <varlistentry>
-          <term><command>exit</command></term>
+          <term><command>exit <optional><replaceable>EXIT_CODE</replaceable></optional></command></term>
 
           <listitem>
             <para>Ask the systemd manager to quit. This is only
             supported for user service managers (i.e. in conjunction
-            with the <option>--user</option> option) and will fail
-            otherwise.</para>
+            with the <option>--user</option> option) or in containers
+            and is equivalent to <command>poweroff</command> otherwise.</para>
+
+            <para>The systemd manager can exit with a non-zero exit
+            code if the optional argument
+            <replaceable>EXIT_CODE</replaceable> is given.</para>
           </listitem>
         </varlistentry>
 
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