On 02/08/2016 02:30 PM, Sage Weil wrote:
On Mon, 8 Feb 2016, Nathan Cutler wrote:
In master we currently have an issue with the systemd unit files in that they
contain hard-coded paths that are specific to RH/CentOS/Fedora. Other distros
can and do have the executables in different places.
I opened a bug[1] for this, but before I go off trying to fix it I would like
to solicit your feedback on the following possible approaches I came up with
(and/or "turn me on" to a different approach):
(1) Rely on PATH. Basically, instead of running executables directly, run them
by "/bin/sh -c", which summons the system PATH to help find the executables.
See https://github.com/ceph/ceph/pull/6803 for an example of this.
(2) Set environment variables in /etc/sysconfig/ceph. Systemd has an
EnvironmentFile directive which reads environment variables from a file. If
this were pointed to /etc/sysconfig/ceph (as it is in several unit files
already), we could set the distro-specific parts of the paths there and write
the paths similar to how we do it in the spec file.
(3) Generate unit files at build time. In this approach, the unit files would
exist in the source tree as templates (e.g. ceph-osd@xxxxxxxxxxx) and these
would get transformed into the "real" unit files at build time. The
ceph-detect-init utility could be used to determine the distro and the
Makefile logic would then fill in the templates as needed for the distro.
Of these three approaches, only (3) would seem to be general enough to work
nicely for all distros. (For example, EnvironmentFile will need to be set to
/etc/default/ceph on Debianesque systems and there is no obvious way to set
*this* path as an environment variable.)
If (1) isn't enough to get us by, then I agree that (3) seems to be the
cleanest. But autoconf/automake at least should be able to feed these
paths into the .in file without needed ceph-detect-init, right? Which
paths are you having problems with?
(1) is indeed tempting as a quick fix. But we still have at least one
problematic path - the /usr/sbin/ceph-disk in:
https://github.com/ceph/ceph/blob/master/systemd/ceph-disk%40.service#L7
Because on SUSE ceph-disk is installed in /usr/bin.
(As for (3), I guess you're right that autoconf would be able to figure
out the paths.)
Thanks
--
Nathan Cutler
Software Engineer Distributed Storage
SUSE LINUX, s.r.o.
Tel.: +420 284 084 037
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