mariadb: switch init to mysqld_safe and mysqladmin

mysqld_safe is the recommended way to start the server on non-systemd
systems ([1]). For instance, it has a crash detection with auto-restart
function, can update ulimits, setup core files, set the niceness of the
server etc. It looks like it could also be helpful when trying to set up
clusters. It's maintained upstream and adding it means we don't need to
add these features into our init script.

mysqld_safe is a script itself, so it's added to conffiles in case users
want to edit it.

It can't be run under procd, so the init script is converted to a normal
System V type. To stop the server and to reload the privileges tables
mysqladmin is used. To that end mysqladmin is moved into the server
package.

While changing the init script, the Debian init script was used for
ideas. It wasn't copied verbatim and adapted a bit here and there.
Thanks to whoever wrote it!

This commit removes the support for starting the service as a user other
than "mariadb". This makes the init script simpler. If anybody wants to
play around with the user then it's up to them to fix the permissions.

[1] https://mariadb.com/kb/en/mysqld_safe/

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

2 files changed, 84 insertions, 96 deletions

diff --git a/utils/mariadb/files/mysqld.config b/utils/mariadb/files/mysqld.config
index 1bfcde6c5..1e866e1ec 100644
--- a/utils/mariadb/files/mysqld.config
+++ b/utils/mariadb/files/mysqld.config
@@ -1,7 +1,5 @@
 
 config mysqld 'general'
-	option enabled '0'
-	option log_stderr '1'
-	option log_stdout '1'
-	option options ''
+	option enabled '0'			# 0 - disabled, 1 - enabled
+	option options '--syslog'		# Options passed to mysqld_safe
 
diff --git a/utils/mariadb/files/mysqld.init b/utils/mariadb/files/mysqld.init
index 284e00aaa..a1e6a44b1 100644
--- a/utils/mariadb/files/mysqld.init
+++ b/utils/mariadb/files/mysqld.init
@@ -4,47 +4,70 @@
 START=95
 STOP=10
 
-USE_PROCD=1
-
-#PROCD_DEBUG=1
-
 NAME=mysqld
 
 LOGGER="/usr/bin/logger -p user.err -s -t $NAME --"
-COMMAND=/usr/bin/$NAME
+
+MYSQLADMIN=/usr/bin/mysqladmin
+MYSQLD=/usr/bin/$NAME
+MYSQLDSAFE=/usr/bin/mysqld_safe
+
+# mysqladmin likes to read /root/.my.cnf which could cause issues.
+export HOME=/etc/mysql
+
+# Safeguard (relative paths, core dumps...)
+cd /
 
 mysqld_get_param() {
-	$COMMAND --print-defaults \
+	$MYSQLD --print-defaults \
 		| tr " " "\n" \
 		| grep -- "--$1" \
 		| tail -n 1 \
 		| cut -d= -f2
 }
 
-start_service() {
-	local conf=/etc/mysql/my.cnf
-	local dir
-	local user
-	local group
+# Checks if a server is running and accessible.
+#
+# check_alive insists on a pingable server
+# check_dead also fails if there is a lost mysqld in the process list
+#
+# Usage: boolean mysqld_status [check_alive|check_dead]
+mysqld_status() {
+	if $MYSQLADMIN ping >/dev/null 2>&1; then
+		ping_alive=1
+	else
+		ping_alive=0
+	fi
 
-	local logfile
+	ps_alive=0
+	pidfile=$(mysqld_get_param pid-file)
+	if [ -f "$pidfile" ] && kill -0 $(cat "$pidfile") >/dev/null 2>&1; then
+		ps_alive=1
+	fi
 
-	local datadir
-	local logdir=/var/log/mysql
-	local rundir=/var/run/mysqld
-	local tmpdir
+	if { [ "$1" = check_alive ] && [ $ping_alive = 1 ]; } || \
+		{ [ "$1" = check_dead ] && [ $ping_alive = 0 ] \
+					&& [ $ps_alive = 0 ]; }
+	then
+		return 0 # EXIT_SUCCESS
+	else
+		return 1 # EXIT_FAILURE
+	fi
+}
 
-	local enabled
-	local log_stderr
-	local log_stdout
-	local options
+start() {
+	conf=/etc/mysql/my.cnf
+	logdir=/var/log/mysql
+	rundir=/var/run/mysqld
 
-	local hint="please fix your server configuration in /etc/mysql/"
+	hint="please fix your server configuration in /etc/mysql/"
 
-	if [ ! -x $COMMAND ]; then
-		$LOGGER $COMMAND is missing
-		exit 1
-	fi
+	for i in $MYSQLD $MYSQLADMIN $MYSQLDSAFE; do
+		if [ ! -x $i ]; then
+			$LOGGER $i is missing
+			exit 1
+		fi
+	done
 
 	if [ ! -r $conf ]; then
 		$LOGGER $conf cannot be read
@@ -59,15 +82,10 @@ start_service() {
 		exit 1
 	fi
 
-	config_get_bool log_stderr general log_stderr 1
-	config_get_bool log_stdout general log_stdout 1
-
 	config_get options general options
 
 	datadir=$(mysqld_get_param datadir)
-	logfile=$(mysqld_get_param general_log_file)
 	tmpdir=$(mysqld_get_param tmpdir)
-	user=$(mysqld_get_param user)
 
 	if [ -z "$datadir" ]; then
 		$LOGGER datadir is not set
@@ -81,76 +99,48 @@ start_service() {
 		exit 1
 	fi
 
-	if [ -z "$user" ]; then
-		$LOGGER user is not set
-		$LOGGER $hint
-		exit 1
-	fi
-
-	user_exists "$user" || {
-		$LOGGER user \""$user"\" does not exist
-		$LOGGER $hint
-		exit 1
-	}
-
-	group=$(id -g -n "$user")
-
-	group_exists "$group" || {
-		$LOGGER group \""$group"\" does not exist
-		$LOGGER user \""$user"\" not configured correctly
-		exit 1
-	}
-
-	[ -n "$logfile" ] && logdir=$(dirname "$logfile")
-
-	# do not touch directories that already exist
-	# posix shell does not support arrays, hence using awk
-	awk \
-	  -v user="$user" \
-	  -v group="$group" \
-	  -v a="$datadir" \
-	  -v b="$logdir" \
-	  -v c="$rundir" \
-	  -v d="$tmpdir" \
-	  '
-	    BEGIN {
-	      dir[0]=a
-	      dir[1]=b
-	      dir[2]=c
-	      dir[3]=d
-	      for (x in dir) {
-	        if (system("test ! -e \"" dir[x] "\"" )) {
-	          delete dir[x]
-	        }
-	      }
-	      for (x in dir) {
-	        system("mkdir -p \"" dir[x] "\"" )
-	        system("chmod 750 \"" dir[x] "\"" )
-	        system("chown \"" user "\":\"" group "\" \"" dir[x] "\"" )
-	      }
-	    }
-	  '
-
 	if [ ! -f "$datadir/mysql/tables_priv.MAD" ]; then
-		local args="--force"
-		local basedir=$(mysqld_get_param basedir)
+		args="--force"
+		basedir=$(mysqld_get_param basedir)
 		[ -n "$basedir" ] && args="$args --basedir=$basedir"
 
 		$LOGGER Cannot detect privileges table. You might need to run
-		$LOGGER \'mysql_install_db $args\'
+		$LOGGER \'mysql_install_db "$args"\'
 		$LOGGER to initialize the system tables.
 		exit 1
 	fi
 
-	procd_open_instance
-
-	procd_set_param command $COMMAND $options
-
-	# forward stderr to logd
-	procd_set_param stderr $log_stderr
-	# same for stdout
-	procd_set_param stdout $log_stdout
+	# Start daemon
+	if mysqld_status check_alive; then
+		$LOGGER already running
+	else
+		for i in $logdir $rundir; do
+			opts="-m 0750"
+			if ! [ -e $i ]; then
+				# $rundir needs to be accessible for
+				# clients
+				if [ $i = $rundir ]; then
+					opts=
+				fi
+				mkdir -p $opts $i
+				[ -d $i ] && chown mariadb:mariadb $i
+			fi
+		done
+
+		$MYSQLDSAFE $options >/dev/null 2>&1 &
+	fi
+}
 
-	procd_close_instance
+stop() {
+	if ! mysqld_status check_dead; then
+		$MYSQLADMIN shutdown
+	fi
 }
 
+reload() {
+	if mysqld_status check_alive; then
+		$MYSQLADMIN reload
+	else
+		$LOGGER not running
+	fi
+}