#!/bin/bash
#
# Scripts to run by MySQL systemd service
#
# Needed argument: pre | post
#
# pre mode  :  try to perform sanity check for configuration, log, data
# post mode :  ping server until answer is received

# Read a config option from mysql. Note that this will only work if a config
# file actually specifies the option, so it's important to specify a default
# $1 is application (e.g. mysqld for server)
# $2 is option
# $3 is default value used if no config value is found
get_mysql_option() {
        result=$(my_print_defaults "$1" | sed -n "s/^--$2=//p" | tail -n 1)
        if [ -z "$result" ];
        then
                result="$3"
        fi
        echo "$result"
}
sanity () {
  if [ ! -r /etc/mysql/my.cnf ]; then
    echo "MySQL configuration not found at /etc/mysql/my.cnf. Please create one."
    exit 1
  fi
  datadir=$(get_mysql_option mysqld datadir "/var/lib/mysql")
  if [ ! -d "${datadir}" ] && [ ! -L "${datadir}" ]; then
    echo "MySQL data dir not found at ${datadir}. Please create one."
    exit 1
  fi

  if [ ! -d "${datadir}/mysql" ] && [ ! -L "${datadir}/mysql" ]; then
    echo "MySQL system database not found in ${datadir}. Please run mysqld --initialize."
    exit 1
  fi
}

pinger () {
  server_up=false
  for i in $(seq 1 30); do
    sleep 1
    if mysqladmin ping >/dev/null 2>&1; then
      server_up=true
      break
    fi
  done
  if [ ! $server_up ]; then
    echo "MySQL server not started"
    exit 1
  fi
}

case $1 in
  "pre")  sanity ;;
  "post") pinger ;;
esac