##
#
# MySQL and MariaDB socket-file/pid-file folder issues – how to fix
#
##

# ----------
# There are 2 possibilities to force creating a folder on ech boot.
# ----------


# ----------
#
# 1.) Add 'ExecStartPre' directive to systemd service file:
#
#    ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/run/mysqld
#
# ----------

MYSQL_USER=mysql
SOCKET_DIR="/var/run/mysqld"
MYSQL_SERVICE_FILE="/root/mysql.service"

perl -i -n -p -e "s&^(PermissionsStartOnly=.*)&\1\n\nExecStartPre=/usr/bin/install -m 755 -o $MYSQL_USER -g root -d $SOCKET_DIR&" $MYSQL_SERVICE_FILE 


# ----------
#
# 2.) Create file /etc/tmpfiles.d/mysql.conf file with content:
#
#    # systemd tmpfile settings for mysql or mariadb
#    d /var/run/mysqld 0755 mysql mysql -
#
# see also: 
#    https://www.ryadel.com/en/linux-mysql-mariadb-pid-file-folder-fix/
#
# ----------

# Force systemd to create such folder on each startup.  We can easily do that following the steps below:
#
#    - Create a new /etc/tmpfiles.d/mysql.conf file with content:
#
#       # systemd tmpfile settings for mysql or mariadb
#       d /var/run/mysqld 0755 mysql mysql -
#
cat <<EOF > /etc/tmpfiles.d/mysql.conf
# systemd tmpfile settings for mysql or mariadb
d /var/run/mysqld 0755 mysql mysql -
EOF