mariadb: improve packaging and configuration

At present there are some flaws related to configuration, also related
to the packaging of mariadb. For starters there are complaints that the
configuration is too static.

To address this a new configuration layout is introduced. The primary
configuration file (my.cnf) is changed so that it now only includes
further configuration files in the directory /etc/mysql/conf.d. More
default configuration files are added for the server and the client.
This is the new default configuration.

With these changes it's possible for the user to select if they want to
change the default configuration (in conf.d/*.cnf) or if they want to
drop their own files into conf.d instead. If the user .cnf files are
read after the default .cnf files (files are included in alphabetical
order), they will overwrite the settings from the default configuration.

The other flaw is that the my.cnf file is included in mariadb-server.
But that doesn't really fit the requirements, as the client also uses
the configuration file(s). To accomodate this a new package
mariadb-common is added. It installs the shared my.cnf file.

The remaining changes add base packages, both for the server and the
client. These are meant as foundation for the packages containing the
respective binaries. In summary they will install the configuration,
small miscellaneous files (SQL scripts etc.) and the user "mariadb".

That means that everything is ready for the binaries, like mysql and
mysqld. If there is not enough space left on flash memory, the user can
just drop the binaries on a pendrive, link them to /usr/bin and get
started.

The ideas and configuration files were copied from Debian. Some
amendments were made.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

utils/mariadb/Makefile

@@ -211,7 +211,7 @@ define Package/libmariadb/Default
 endef
 
 define Package/libmariadb
-$(call Package/libmariadb/Default)
+  $(call Package/libmariadb/Default)
   DEPENDS:=$(MARIADB_COMMON_DEPENDS)
   TITLE:=MariaDB database client library
   MENU:=1
@@ -234,10 +234,9 @@ endef
 
 define Package/mariadb-client
   $(call Package/mariadb/Default)
-  TITLE:=MariaDB database core client binaries
-  DEPENDS:= \
-	  $(MARIADB_COMMON_DEPENDS) \
-	  +libedit
+  TITLE:=MariaDB database client
+  MENU:=1
+  DEPENDS:=mariadb-client-base
 endef
 
 define Package/mariadb-client/description
@@ -249,9 +248,30 @@ $(subst $(space),$(newline),$(MARIADB_CLIENT))
 
 endef
 
+define Package/mariadb-client-base
+  $(call Package/mariadb/Default)
+  TITLE:=MariaDB database client base
+  DEPENDS:=mariadb-common \
+	  $(MARIADB_COMMON_DEPENDS) \
+	  +libedit
+endef
+
+define Package/mariadb-client-base/conffiles
+$(CONF_DIR)/conf.d/50-client.cnf
+$(CONF_DIR)/conf.d/50-mysql-clients.cnf
+endef
+
+define Package/mariadb-client-base/description
+$(call Package/mariadb/description/Default)
+
+This package provides the foundation for mariadb-client. It installs the
+configuration and the dependencies.
+
+endef
+
 define Package/mariadb-client-extra
   $(call Package/mariadb/Default)
-  TITLE:=MariaDB database extra client binaries
+  TITLE:=MariaDB database client extra
   DEPENDS:=mariadb-client
 endef
 
@@ -264,6 +284,23 @@ $(subst $(space),$(newline),$(MARIADB_CLIENT_EXTRA))
 
 endef
 
+define Package/mariadb-common
+  $(call Package/mariadb/Default)
+  TITLE:=MariaDB database common files
+  DEPENDS:=
+endef
+
+define Package/mariadb-common/conffiles
+$(CONF_DIR)/my.cnf
+endef
+
+define Package/mariadb-common/description
+$(call Package/mariadb/description/Default)
+
+This package includes shared files, for example $(CONF_DIR)/my.cnf.
+
+endef
+
 define Package/mariadb-extra-charsets
   $(call Package/mariadb/Default)
   TITLE:=MariaDB database extra character sets
@@ -280,16 +317,10 @@ endef
 
 define Package/mariadb-server
   $(call Package/mariadb/Default)
-  DEPENDS:= \
-	  $(MARIADB_COMMON_DEPENDS) \
-	  +!arc:libaio \
-	  +liblzma \
-	  +libpcre \
-	  +resolveip
-  TITLE:=MariaDB database core server binaries
+  DEPENDS:=mariadb-server-base
+  TITLE:=MariaDB database server
   MENU:=1
   PROVIDES:=mysql-server
-  USERID:=mariadb=376:mariadb=376
 endef
 
 define Package/mariadb-server/description
@@ -301,9 +332,35 @@ $(subst $(space),$(newline),$(MARIADB_SERVER))
 
 endef
 
+define Package/mariadb-server-base
+  $(call Package/mariadb/Default)
+  DEPENDS:=mariadb-common \
+	  $(MARIADB_COMMON_DEPENDS) \
+	  +!arc:libaio \
+	  +liblzma \
+	  +libpcre \
+	  +resolveip
+  TITLE:=MariaDB database server base
+  USERID:=mariadb=376:mariadb=376
+endef
+
+define Package/mariadb-server-base/conffiles
+$(CONF_DIR)/conf.d/50-server.cnf
+/etc/default/mysqld
+endef
+
+define Package/mariadb-server-base/description
+$(call Package/mariadb/description/Default)
+
+This package provides the foundation for mariadb-server. It installs the
+init script, support files (configuration etc.), the user "mariadb" and
+the dependencies.
+
+endef
+
 define Package/mariadb-server-extra
   $(call Package/mariadb/Default)
-  TITLE:=MariaDB database extra server binaries
+  TITLE:=MariaDB database server extra
   DEPENDS:=mariadb-server
 endef
 
@@ -488,11 +545,22 @@ define Package/mariadb-client/install
 	cd $(1)/usr/bin; $(LN) mysqlcheck mysqloptimize
 endef
 
+define Package/mariadb-client-base/install
+	$(INSTALL_DIR) $(1)$(CONF_DIR)/conf.d
+	$(INSTALL_CONF) conf/50-client.cnf $(1)$(CONF_DIR)/conf.d
+	$(INSTALL_CONF) conf/50-mysql-clients.cnf $(1)$(CONF_DIR)/conf.d
+endef
+
 define Package/mariadb-client-extra/install
 	$(INSTALL_DIR) $(1)/usr/bin
 	$(foreach b,$(MARIADB_CLIENT_EXTRA),$(call Package/mariadb/install/bin,$(1),$(b));)
 endef
 
+define Package/mariadb-common/install
+	$(INSTALL_DIR) $(1)$(CONF_DIR)
+	$(INSTALL_CONF) conf/my.cnf $(1)$(CONF_DIR)
+endef
+
 define Package/mariadb-extra-charsets/install
 	$(INSTALL_DIR) $(1)$(SHARE_DIR)/charsets
 	$(INSTALL_DATA) $(PKG_INSTALL_DIR)$(SHARE_DIR)/charsets/* $(1)$(SHARE_DIR)/charsets
@@ -501,13 +569,16 @@ endef
 define Package/mariadb-server/install
 	$(INSTALL_DIR) $(1)/usr/bin
 	$(foreach b,$(MARIADB_SERVER),$(call Package/mariadb/install/bin,$(1),$(b));)
+endef
+
+define Package/mariadb-server-base/install
+	$(INSTALL_DIR) $(1)$(CONF_DIR)/conf.d
+	$(INSTALL_DIR) $(1)$(SHARE_DIR)/english
 	$(INSTALL_DIR) $(1)/etc/default
 	$(INSTALL_DIR) $(1)/etc/init.d
-	$(INSTALL_DIR) $(1)$(CONF_DIR)/conf.d
 	$(INSTALL_BIN) files/mysqld.init $(1)/etc/init.d/mysqld
-	$(INSTALL_CONF) conf/my.cnf $(1)$(CONF_DIR)
+	$(INSTALL_CONF) conf/50-server.cnf $(1)$(CONF_DIR)/conf.d
 	$(INSTALL_CONF) conf/mysqld.default $(1)/etc/default/mysqld
-	$(INSTALL_DIR) $(1)$(SHARE_DIR)/english
 	$(INSTALL_DATA) $(PKG_INSTALL_DIR)$(SHARE_DIR)/english/errmsg.sys $(1)$(SHARE_DIR)/english
 	$(INSTALL_DATA) $(PKG_INSTALL_DIR)$(SHARE_DIR)/fill_help_tables.sql $(1)$(SHARE_DIR)
 	$(INSTALL_DATA) $(PKG_INSTALL_DIR)$(SHARE_DIR)/maria_add_gis_sp_bootstrap.sql $(1)$(SHARE_DIR)
@@ -521,11 +592,6 @@ define Package/mariadb-server-extra/install
 	$(foreach b,$(MARIADB_SERVER_EXTRA),$(call Package/mariadb/install/bin,$(1),$(b));)
 endef
 
-define Package/mariadb-server/conffiles
-/etc/default/mysqld
-$(CONF_DIR)/my.cnf
-endef
-
 define BuildPlugin
   define Package/$(1)-plugin-$(subst _,-,$(2))
     $(call Package/$(subst mariadb-server,mariadb,$(1))/Default)
@@ -548,9 +614,12 @@ endef
 $(eval $(call HostBuild))
 $(eval $(call BuildPackage,libmariadb))
 $(eval $(call BuildPackage,mariadb-client))
+$(eval $(call BuildPackage,mariadb-client-base))
 $(eval $(call BuildPackage,mariadb-client-extra))
+$(eval $(call BuildPackage,mariadb-common))
 $(eval $(call BuildPackage,mariadb-extra-charsets))
 $(eval $(call BuildPackage,mariadb-server))
+$(eval $(call BuildPackage,mariadb-server-base))
 $(eval $(call BuildPackage,mariadb-server-extra))
 
 $(eval $(call BuildPlugin,libmariadb,auth_gssapi_client,+krb5-libs))