base-passwd/useradd: Various improvements to useradd with RSS

Currently there are multiple issues with useradd:

* If base-passwd rebuilds, it wipes out recipe specific user/group additions
  to sysroots and causes errors
* If recipe A adds a user and recipe B depends on A, it can't see any of the
  users/groups A adds.

This patch changes base-passwd so it always works as a postinst script
within the sysroot and copies in the master files, then runs any
postinst-useradd-* scripts afterwards to add additional user/groups.

The postinst-useradd-* scripts are tweaked so that if /etc/passwd doesn't exist
they just exit, knowning they'll be executed later. We also add a dummy entry to
the dummy passwd file from pseudo so we can avoid this too.

There is a problem where if recipe A adds a user and recipe B depends on A but
doesn't care about users, it may not have a dependency on the useradd/groupadd
tools which would therefore not be available in B's sysroot. We therefore also
tweak postinst-useradd-* scripts so that if the tools aren't present we simply
don't add users. If you need the users, you add a dependency on the tools in the
recipe and they'll be added.

We add postinst-* to SSTATE_SCAN_FILES since almost any postinst script of this
kind is going to need relocation help.

We also ensure that the postinst-useradd script is written into the sstate
object as the current script was only being added in a recipe local way.

Thanks to Peter Kjellerstedt <pkj@axis.com> and Patrick Ohly for some pieces
of this patch.

[Yocto #11124]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 22 insertions, 6 deletions

diff --git a/meta/recipes-core/base-passwd/base-passwd_3.5.29.bb b/meta/recipes-core/base-passwd/base-passwd_3.5.29.bb
index e43bc0a007..c6be1c1d08 100644
--- a/meta/recipes-core/base-passwd/base-passwd_3.5.29.bb
+++ b/meta/recipes-core/base-passwd/base-passwd_3.5.29.bb
@@ -43,16 +43,32 @@ do_install () {
 	install -p -m 644 ${S}/debian/copyright ${D}${docdir}/${BPN}/
 }
 
+basepasswd_sysroot_postinst() {
+#!/bin/sh
+
+# Install passwd.master and group.master to sysconfdir
+install -d -m 755 ${STAGING_DIR_TARGET}${sysconfdir}
+for i in passwd group; do
+	install -p -m 644 ${STAGING_DIR_TARGET}${datadir}/base-passwd/\$i.master \
+		${STAGING_DIR_TARGET}${sysconfdir}/\$i
+done
+
+# Run any useradd postinsts
+for script in ${STAGING_DIR_TARGET}${bindir}/postinst-useradd-*; do
+	if [ -f \$script ]; then
+		\$script
+	fi
+done
+}
+
 SYSROOT_DIRS += "${sysconfdir}"
 SYSROOT_PREPROCESS_FUNCS += "base_passwd_tweaksysroot"
 
 base_passwd_tweaksysroot () {
-	# Install passwd.master and group.master to sysconfdir
-	install -d -m 755 ${SYSROOT_DESTDIR}${sysconfdir}
-	for i in passwd group; do
-		install -p -m 644 ${SYSROOT_DESTDIR}${datadir}/base-passwd/$i.master \
-			${SYSROOT_DESTDIR}${sysconfdir}/$i
-	done
+	mkdir -p ${SYSROOT_DESTDIR}${bindir}
+	dest=${SYSROOT_DESTDIR}${bindir}/postinst-${PN}
+	echo "${basepasswd_sysroot_postinst}" > $dest
+	chmod 0755 $dest
 }
 
 python populate_packages_prepend() {