[OE-core] [PATCH v3 2/5] systemd-conf: simplify creation of machine-specific configuration

[Jonas Bonn]

The configuration files that systemd installs are just skeletons
detailing the available options and their default values.  The
recommended means of changing the configuration is to provide snippets
in configuration directories.  For example, journald.conf settings are
best set in /usr/lib/journald.conf.d/ and can be overridden by the user
by providing overriding snippets in /etc/systemd/journald.conf.d/.

The systemd-conf package is just providing machine-specific overrides
for some systemd defaults.

This patch restores the installation of config files by systemd and
reduces systemd-conf to just providing the config snippets in
/usr/lib/*.conf.d.  This simplfies the systemd-conf recipe considerably
since it now just sets up a couple of text files and doesn't even need
access to the systemd source anymore.

Given, however, that the base configuration files in /etc/systemd have
the lowest priority, they will always be overridden by any snippets.  As
it may confuse a user who is used to modifying these base files
directly, this patch puts symlinks in the overriding
/etc/systemd/*.conf.d/ directories back to the top-level files, thereby
restoring them to their top-level glory.  The default config files
installed by systemd are just lists of (commented out) defaults so this
should be safe.  The symlinks also provide an indication to the user
that there is more to systemd configuration than just the top-level file
and that checking the man page may be in order...

With this patch, systemd gets the right configuration irregardless of
whether /etc is populated at boot or not (i.e. in a "stateless"
system).

License-Update: configuration snippets licensing is independent of
systemd licensing

Signed-off-by: Jonas Bonn <jonas at norrbonn.se>
---
 meta/recipes-core/systemd/systemd-conf.bb | 48 +++++++++++------------
 meta/recipes-core/systemd/systemd_239.bb  | 16 ++++----
 2 files changed, 31 insertions(+), 33 deletions(-)

diff --git a/meta/recipes-core/systemd/systemd-conf.bb b/meta/recipes-core/systemd/systemd-conf.bb
index 7fe2e1105b..8a9f01c48a 100644
--- a/meta/recipes-core/systemd/systemd-conf.bb
+++ b/meta/recipes-core/systemd/systemd-conf.bb
@@ -1,48 +1,44 @@
-require systemd.inc
-
 SUMMARY = "Systemd system configuration"
 DESCRIPTION = "Systemd may require slightly different configuration for \
 different machines.  For example, qemu machines require a longer \
 DefaultTimeoutStartSec setting."
+LICENSE = "MIT"
 
 PACKAGE_ARCH = "${MACHINE_ARCH}"
 
-CONFFILES_${PN} = "${sysconfdir}/systemd/coredump.conf \
-${sysconfdir}/systemd/journald.conf \
-${sysconfdir}/systemd/logind.conf \
-${sysconfdir}/systemd/system.conf \
-${sysconfdir}/systemd/user.conf"
-
-FILES_${PN} = "${sysconfdir}/systemd"
-
-do_configure[noexec] = '1'
-do_compile[noexec] = '1'
+FILES_${PN} = "/usr/lib/journald.conf.d/* \
+	/usr/lib/logind.conf.d/* \
+	/usr/lib/system.conf.d/* \
+	/etc/systemd/* \
+"
 
 do_install() {
-	rm -rf ${D}/${sysconfdir}/systemd
-	install -d ${D}/${sysconfdir}/systemd
-
-	install -m 0644 ${S}/src/coredump/coredump.conf ${D}${sysconfdir}/systemd/coredump.conf
-
-	install -m 0644 ${S}/src/journal/journald.conf ${D}${sysconfdir}/systemd/journald.conf
+	install -d ${D}/usr/lib/journald.conf.d
 	# Enable journal to forward message to syslog daemon
-	sed -i -e 's/.*ForwardToSyslog.*/ForwardToSyslog=yes/' ${D}${sysconfdir}/systemd/journald.conf
+	echo "ForwardToSyslog=yes" >> ${D}/usr/lib/journald.conf.d/00-${PN}.conf
 	# Set the maximium size of runtime journal to 64M as default
-	sed -i -e 's/.*RuntimeMaxUse.*/RuntimeMaxUse=64M/' ${D}${sysconfdir}/systemd/journald.conf
+	echo "RuntimeMaxUse=64M" >> ${D}/usr/lib/journald.conf.d/00-${PN}.conf
+
+	install -d ${D}${sysconfdir}/systemd/journald.conf.d
+	ln -s ../journald.conf ${D}${sysconfdir}/systemd/journald.conf.d/00-${PN}.conf
 
-	install -m 0644 ${S}/src/login/logind.conf.in ${D}${sysconfdir}/systemd/logind.conf
+	install -d ${D}/usr/lib/logind.conf.d
 	# Set KILL_USER_PROCESSES to yes
-	sed -i -e 's/@KILL_USER_PROCESSES@/yes/' ${D}${sysconfdir}/systemd/logind.conf
+	echo "KillUserProcesses=yes" >> ${D}/usr/lib/logind.conf.d/00-${PN}.conf
+
+	install -d ${D}${sysconfdir}/systemd/logind.conf.d
+	ln -s ../logind.conf ${D}${sysconfdir}/systemd/logind.conf.d/00-${PN}.conf
 
-	install -m 0644 ${S}/src/core/system.conf.in ${D}${sysconfdir}/systemd/system.conf
+	install -d ${D}/usr/lib/system.conf.d
 	# Set MEMORY_ACCOUNTING_DEFAULT to yes
-	sed -i -e 's/@MEMORY_ACCOUNTING_DEFAULT@/yes/' ${D}${sysconfdir}/systemd/system.conf
+	echo "DefaultMemoryAccounting=yes" >> ${D}/usr/lib/system.conf.d/00-${PN}.conf
 
-	install -m 0644 ${S}/src/core/user.conf ${D}${sysconfdir}/systemd/user.conf
+	install -d ${D}${sysconfdir}/systemd/system.conf.d
+	ln -s ../system.conf ${D}${sysconfdir}/systemd/system.conf.d/00-${PN}.conf
 }
 
 # Based on change from YP bug 8141, OE commit 5196d7bacaef1076c361adaa2867be31759c1b52
 do_install_append_qemuall() {
 	# Change DefaultTimeoutStartSec from 90s to 240s
-	echo "DefaultTimeoutStartSec = 240s" >> ${D}${sysconfdir}/systemd/system.conf
+	echo "DefaultTimeoutStartSec = 240s" >> ${D}/usr/lib/system.conf.d/00-${PN}.conf
 }
diff --git a/meta/recipes-core/systemd/systemd_239.bb b/meta/recipes-core/systemd/systemd_239.bb
index 54217d3042..c6b93251b3 100644
--- a/meta/recipes-core/systemd/systemd_239.bb
+++ b/meta/recipes-core/systemd/systemd_239.bb
@@ -291,13 +291,6 @@ do_install() {
 		fi
 	fi
 
-	# conf files are handled by systemd-conf
-	rm -f ${D}${sysconfdir}/systemd/coredump.conf
-	rm -f ${D}${sysconfdir}/systemd/journald.conf
-	rm -f ${D}${sysconfdir}/systemd/logind.conf
-	rm -f ${D}${sysconfdir}/systemd/system.conf
-	rm -f ${D}${sysconfdir}/systemd/user.conf
-
 	# duplicate udevadm for postinst script
 	install -d ${D}${libexecdir}
 	ln ${D}${base_bindir}/udevadm ${D}${libexecdir}/${MLPREFIX}udevadm
@@ -496,6 +489,15 @@ FILES_${PN}-extra-utils = "\
                         ${rootlibexecdir}/systemd/systemd-cgroups-agent \
 "
 
+CONFFILES_${PN} = "${sysconfdir}/systemd/coredump.conf \
+	${sysconfdir}/systemd/journald.conf \
+	${sysconfdir}/systemd/logind.conf \
+	${sysconfdir}/systemd/system.conf \
+	${sysconfdir}/systemd/user.conf \
+	${sysconfdir}/systemd/resolved.conf \
+	${sysconfdir}/systemd/timesyncd.conf \
+"
+
 FILES_${PN} = " ${base_bindir}/* \
                 ${base_sbindir}/shutdown \
                 ${base_sbindir}/halt \
-- 
2.19.1