Bash script using rc.status executing twice on newer SLES

Question

I have the strange phenomenon that a long-standing admin script started running more or less twice when we moved from SLES 11 to SLES 12 (SuSE Enterprise Linux). I could track this down to being related to /etc/rc.status with a minimal example test.sh:

#!/bin/bash
echo Sourcing rc.status
. /etc/rc.status
echo End of script

When this is run with status as parameter (a common use-case for my script)...

./test.sh status

...I observe this output:

Sourcing rc.status
Sourcing rc.status
End of script
End of script

What gives?

Answer 1

Turns out there's been some poettering in the SLES /etc/rc.status file:

user@host:~> diff rc.status.sles11 /etc/rc.status
34a35,92
> # Check if the service is used under systemd but not started with
> if test -z "$SYSTEMD_NO_WRAP" && /usr/bin/mountpoint -q /sys/fs/cgroup/systemd; then
>     if test $PPID -ne 1 -a $# -eq 1 ; then
>       _rc_base=
...

So the solution is to set SYSTEMD_NO_WRAP before sourcing /etc/rc.status.

#!/bin/bash
echo Sourcing rc.status
SYSTEMD_NO_WRAP=1
. /etc/rc.status
echo End of script

This gives the expected behaviour:

Sourcing rc.status
End of script