[meta-oe][PATCH] volatile-binds: Calculate the name of the /var/lib service

["Stéphane Veyret" <sveyret@gmail.com>]

By default, /var/lib is bind mounted on /var/volatile/lib. If this is
the case, the recipe adds conditions on systemd-random-seed in the
service file mounting it. But as the VOLATILE_BINDS may be modified,
/var/lib may be mounted elsewhere, for example in /persistent/var/lib.
In this case, the conditions are not set because the service file name
does not match expected one.
This patch automatically records the name of the service mounting
/var/lib, if any, in order to set the condition in the appropriate file.

Signed-off-by: Stéphane Veyret <sveyret@gmail.com>
---
 meta/recipes-core/volatile-binds/volatile-binds.bb | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/meta/recipes-core/volatile-binds/volatile-binds.bb b/meta/recipes-core/volatile-binds/volatile-binds.bb
index 3fefa9abde..7a3f53c3ed 100644
--- a/meta/recipes-core/volatile-binds/volatile-binds.bb
+++ b/meta/recipes-core/volatile-binds/volatile-binds.bb
@@ -48,6 +48,7 @@ do_compile () {
 
         servicefile="${spec#/}"
         servicefile="$(echo "$servicefile" | tr / -).service"
+        [ "${mountpoint}" = /var/lib ] && var_lib_servicefile=$servicefile
         sed -e "s#@what@#$spec#g; s#@where@#$mountpoint#g" \
             -e "s#@whatparent@#${spec%/*}#g; s#@whereparent@#${mountpoint%/*}#g" \
             -e "s#@avoid_overlayfs@#${@d.getVar('AVOID_OVERLAYFS')}#g" \
@@ -56,12 +57,12 @@ do_compile () {
 ${@d.getVar('VOLATILE_BINDS').replace("\\n", "\n")}
 END
 
-    if [ -e var-volatile-lib.service ]; then
+    if [ -n ${var_lib_servicefile} ] && [ -e ${var_lib_servicefile} ]; then
         # As the seed is stored under /var/lib, ensure that this service runs
         # after the volatile /var/lib is mounted.
         sed -i -e "/^Before=/s/\$/ systemd-random-seed.service/" \
                -e "/^WantedBy=/s/\$/ systemd-random-seed.service/" \
-               var-volatile-lib.service
+               ${var_lib_servicefile}
     fi
 }
 do_compile[dirs] = "${WORKDIR}"
-- 
2.41.0