From 287419c119ef961db487a281162ab037eba70c61 Mon Sep 17 00:00:00 2001 From: Alban Crequy 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 --- src/systemctl/systemctl.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) (limited to 'src/systemctl') diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c index d1e443b8a6..e20fc1bbbb 100644 --- a/src/systemctl/systemctl.c +++ b/src/systemctl/systemctl.c @@ -3005,6 +3005,7 @@ static int prepare_firmware_setup(sd_bus *bus) { } static int start_special(sd_bus *bus, char **args) { + _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; enum action a; int r; @@ -3029,6 +3030,31 @@ static int start_special(sd_bus *bus, char **args) { r = update_reboot_param_file(args[1]); if (r < 0) return r; + } else if (a == ACTION_EXIT && strv_length(args) > 1) { + /* If the exit code is not given on the command line, don't + * reset it to zero: just keep it as it might have been set + * previously. */ + uint8_t code = 0; + + r = safe_atou8(args[1], &code); + if (r < 0) { + log_error("Invalid exit code."); + return -EINVAL; + } + + r = sd_bus_call_method( + bus, + "org.freedesktop.systemd1", + "/org/freedesktop/systemd1", + "org.freedesktop.systemd1.Manager", + "SetExitCode", + &error, + NULL, + "y", code); + if (r < 0) { + log_error("Failed to execute operation: %s", bus_error_message(&error, r)); + return r; + } } if (arg_force >= 2 && @@ -6224,7 +6250,7 @@ static void systemctl_help(void) { " poweroff Shut down and power-off the system\n" " reboot [ARG] Shut down and reboot the system\n" " kexec Shut down and reboot the system with kexec\n" - " exit Request user instance exit\n" + " exit [EXIT_CODE] Request user instance or container exit\n" " switch-root ROOT [INIT] Change to a different root file system\n" " suspend Suspend the system\n" " hibernate Hibernate the system\n" @@ -7211,7 +7237,7 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) { { "default", EQUAL, 1, start_special }, { "rescue", EQUAL, 1, start_special }, { "emergency", EQUAL, 1, start_special }, - { "exit", EQUAL, 1, start_special }, + { "exit", LESS, 2, start_special }, { "reset-failed", MORE, 1, reset_failed }, { "enable", MORE, 2, enable_unit, NOBUS }, { "disable", MORE, 2, enable_unit, NOBUS }, -- cgit v1.2.3-54-g00ecf