package/mariadb: add optional systemd dependency

If systemd is used we should enable support in mariadb and enable
"Type=notify" in the mysqld.service unit file

"Type=notify" stops systemd from starting services which depend on mariadb
until it has notified systemd that it has finished starting up, this helps
avoid startup race conditions

Signed-off-by: Danny Wood <danny@rotronics.co.uk>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/mariadb/mariadb.mk

@@ -72,6 +72,13 @@ MARIADB_CONF_OPTS += \
 	-DLIBRESSL_RESULT__TRYRUN_OUTPUT="LibreSSL $(LIBRESSL_VERSION)"
 endif
 
+ifeq ($(BR2_PACKAGE_SYSTEMD),y)
+MARIADB_DEPENDENCIES += systemd
+MARIADB_CONF_OPTS += -DWITH_SYSTEMD=yes
+else
+MARIADB_CONF_OPTS += -DWITH_SYSTEMD=no
+endif
+
 ifeq ($(BR2_PACKAGE_MARIADB_SERVER),y)
 ifeq ($(BR2_PACKAGE_MARIADB_SERVER_EMBEDDED),y)
 MARIADB_CONF_OPTS += -DWITH_EMBEDDED_SERVER=ON

package/mariadb/mysqld.service

@@ -9,6 +9,8 @@ Restart=always
 User=mysql
 RuntimeDirectory=mysql
 RuntimeDirectoryMode=0755
+Type=notify
+NotifyAccess=all
 
 [Install]
 WantedBy=multi-user.target