[backend] introduce $BSConfig::bsserviceuser variable

$BSConfig::bsserviceuser and $BSConfig::bsservicegroup can be used to
configure the user/group under which "bs_service" is running. The defaults
are "obsservicerun" and $BSConfig::bsgroup.

src/backend/BSConfig.pm.template

@@ -77,6 +77,12 @@ our @reposervers = ("http://$hostname:5252");
 our $bsdir = '/srv/obs';
 our $bsuser = 'obsrun';
 our $bsgroup = 'obsrun';
+# user and group for bs_service (if the lxc service wrapper is used, set
+# $bsserviceuser to root). If several obs services (e.g., bs_service and
+# bs_srcserver) run on the same host, make sure that $bsservicegroup is set
+# to $bsgroup.
+our $bsserviceuser = 'obsservicerun';
+our $bsservicegroup = $bsgroup;
 #our $bsquotafile = '/srv/obs/quota.xml';
 
 # Use asynchronus scheduler. This avoids hanging schedulers on remote projects,

src/backend/bs_service

@@ -47,8 +47,8 @@ use BSBuild;
 
 use strict;
 
-undef $BSConfig::bsuser;	# need to stay root
-undef $BSConfig::bsgroup;
+$BSConfig::bsuser = $BSConfig::bsserviceuser;
+$BSConfig::bsgroup = $BSConfig::bsservicegroup;
 
 BSUtil::set_fdatasync_before_rename() unless $BSConfig::disable_data_sync || $BSConfig::disable_data_sync;