qemu: Add sysusers config file for qemu & kvm user/groups

Install a systemd sysusers config file for the qemu & kvm user/groups.

We can not use the sysusers_create_compat macro in the RPM specfile to
create those users as we want to keep the specfile standalone and not
relying on additionnal files.

Update the specfile to make the commands closer to what is generated by
the current macro.

See: https://src.fedoraproject.org/rpms/libvirt/pull-request/22
See: https://gitlab.com/libvirt/libvirt/-/merge_requests/319
See: https://bugzilla.redhat.com/show_bug.cgi?id=2095429
See: https://docs.fedoraproject.org/en-US/packaging-guidelines/UsersAndGroups/

Based on previous work by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Timothée Ravier <tim@siosm.fr>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

libvirt.spec.in

@@ -1473,6 +1473,7 @@ chmod 600 $RPM_BUILD_ROOT%{_sysconfdir}/libvirt/nwfilter/*.xml
     %if ! %{with_qemu}
 rm -f $RPM_BUILD_ROOT%{_datadir}/augeas/lenses/libvirtd_qemu.aug
 rm -f $RPM_BUILD_ROOT%{_datadir}/augeas/lenses/tests/test_libvirtd_qemu.aug
+rm -f $RPM_BUILD_ROOT%{_sysusersdir}/libvirt-qemu.conf
     %endif
 %find_lang %{name}
 
@@ -1834,16 +1835,19 @@ exit 0
 %pre daemon-driver-qemu
 %libvirt_sysconfig_pre virtqemud
 %libvirt_systemd_unix_pre virtqemud
+
 # We want soft static allocation of well-known ids, as disk images
-# are commonly shared across NFS mounts by id rather than name; see
+# are commonly shared across NFS mounts by id rather than name.
-# https://fedoraproject.org/wiki/Packaging:UsersAndGroups
+# See https://docs.fedoraproject.org/en-US/packaging-guidelines/UsersAndGroups/
-getent group kvm >/dev/null || groupadd -f -g 36 -r kvm
+# We can not use the sysusers_create_compat macro here as we want to keep the
-getent group qemu >/dev/null || groupadd -f -g 107 -r qemu
+# specfile standalone and not relying on additionnal files.
-if ! getent passwd qemu >/dev/null; then
+getent group 'kvm' >/dev/null || groupadd -f -g '36' -r 'kvm' || :
-  if ! getent passwd 107 >/dev/null; then
+getent group 'qemu' >/dev/null || groupadd -f -g '107' -r 'qemu' || :
-    useradd -r -u 107 -g qemu -G kvm -d / -s /sbin/nologin -c "qemu user" qemu
+if ! getent passwd 'qemu' >/dev/null; then
+  if ! getent passwd '107' >/dev/null; then
+    useradd -r -u '107' -g 'qemu' -G 'kvm' -d '/' -s '/sbin/nologin' -c 'qemu user' 'qemu' || :
   else
-    useradd -r -g qemu -G kvm -d / -s /sbin/nologin -c "qemu user" qemu
+    useradd -r -g 'qemu' -G 'kvm' -d '/' -s '/sbin/nologin' -c 'qemu user' 'qemu' || :
   fi
 fi
 exit 0
@@ -2246,6 +2250,7 @@ exit 0
 %{_bindir}/virt-qemu-run
 %{_mandir}/man1/virt-qemu-run.1*
 %{_mandir}/man8/virtqemud.8*
+%{_sysusersdir}/libvirt-qemu.conf
     %endif
 
     %if %{with_lxc}

src/qemu/libvirt-qemu.sysusers.conf

@@ -0,0 +1,4 @@
+g kvm 36
+g qemu 107
+u qemu 107:qemu "qemu user" - -
+m qemu kvm

src/qemu/meson.build

@@ -160,6 +160,13 @@ if conf.has('WITH_QEMU')
     configuration: qemu_user_group_hack_conf,
   )
 
+  # Install the sysuser config for the qemu driver
+  install_data(
+    'libvirt-qemu.sysusers.conf',
+    install_dir: prefix / 'lib' / 'sysusers.d',
+    rename: [ 'libvirt-qemu.conf' ],
+  )
+
   virt_conf_files += qemu_conf
   virt_aug_files += files('libvirtd_qemu.aug')
   virt_test_aug_files += {