sysmocom-configure: add simple framework to run configuration scripts

The configuration scripts are named for the systemd units for which they
generate configuration files. The generator causes them to run before
those units are started.

If /slot/system.conf is missing, we just exit the generator.

recipes-apps/tasks/task-sysmocom-tools.bb

@@ -17,4 +17,5 @@ RDEPENDS_${PN} = "\
     sysmocom-backup \
     sysmocom-backup-default \
     sysmocom-systemd \
+    sysmocom-configure \
     "

recipes-config/sysmocom-configure/files/multi-user.target.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+set -eu
+
+TEST_VALUE="default"
+
+. /slot/system.conf
+
+cat >/etc/symocom/test.cfg <<EOF
+[main]
+bla=$TEST_VALUE
+EOF

recipes-config/sysmocom-configure/files/osmo-bsc.service.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+set -eu
+
+OSMOBSC_VALUE="bar"
+
+. /slot/system.conf
+
+cat >/etc/osmocom/osmo-bsc.cfg <<EOF
+#dummy: OSMOBSC_VALUE=$OSMOBSC_VALUE
+EOF
+

recipes-config/sysmocom-configure/files/sysmocom-bsc/multi-user.target.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+TEST_VALUE="default"
+
+. /slot/system.conf
+
+cat >/etc/sysmocom/test.cfg <<EOF
+[main]
+bla=$TEST_VALUE
+model=sysmocom-bsc
+EOF

recipes-config/sysmocom-configure/files/sysmocom-generator

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+if [ ! -e /slot/system.conf ]; then
+	exit 0
+fi
+
+. /slot/system.conf
+
+for HANDLER in $(ls /etc/sysmocom/configure.d/*.sh); do
+	UNIT=$(basename "$HANDLER" .sh)
+	cat >$1/${UNIT//./-}-configure.service <<EOF
+[Unit]
+Description=Generate $UNIT Configuration
+After=sysmocom-restore.service
+Before=$UNIT
+
+[Service]
+Type=oneshot
+RemainAfterExit=true
+ExecStart=$HANDLER
+EOF
+	mkdir -p $1/$UNIT.wants
+	ln -s /lib/systemd/system/${UNIT//./-}-configure.service $1/$UNIT.wants/
+done
+
+if [ -n "$OSMOBSC_ENABLED" ]; then
+	ln -s /lib/systemd/system/osmo-bsc.service $1/multi-user.target.wants/
+fi
+
+if [ -n "$OSMONITB_ENABLED" ]; then
+	ln -s /lib/systemd/system/osmo-nitb.service $1/multi-user.target.wants/
+fi

recipes-config/sysmocom-configure/sysmocom-configure_1.0.bb

@@ -0,0 +1,19 @@
+DESCRIPTION = "sysmocom configuration scripts"
+LICENSE = "MIT"
+LIC_FILES_CHKSUM = "file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
+
+SRC_URI = " \
+	file://sysmocom-generator \
+	file://multi-user.target.sh \
+	file://osmo-bsc.service.sh \
+"
+
+do_install() {
+	install -d ${D}${systemd_unitdir}/system-generators
+	install -m 0755 ${WORKDIR}/sysmocom-generator ${D}${systemd_unitdir}/system-generators/
+
+	install -d ${D}${sysconfdir}/sysmocom/configure.d
+	install -m 0755 ${WORKDIR}/*.sh ${D}${sysconfdir}/sysmocom/configure.d/
+}
+
+FILES_${PN} += "${systemd_unitdir}/system-generators"