backup-wpdb.sh

#!/bin/bash

function var() {
  eval $2=`grep -Po  "define\('$3',\s*'(\K[^']+)" $1 | head -n 1`
}

wp_config=$1
base_dir=$2
date_prefix=$(date -u +"%y%m%d%H")

var $wp_config 'db_name' 'DB_NAME'
var $wp_config 'db_user' 'DB_USER'
var $wp_config 'db_password' 'DB_PASSWORD'
var $wp_config 'db_host' 'DB_HOST'

host_name=`dig +short -x ${db_host} | sed 's/.$//'`

if [ -z "$host_name"]
  then
    echo 'no host name'
    host_name=db_host
fi

dir_path=${base_dir}/${db_name}/${host_name}
file_path=${dir_path}/${date_prefix}.${db_host}.sql.gz

mkdir -p ${dir_path}

mysqldump ${db_name} -u ${db_user} -p${db_password} -h ${db_host} --single-transaction | gzip -9 > ${file_path}