automydumper

#!/bin/bash

export PATH="$PATH:/bin:/usr/bin"

# Defaults
backup_root_dir='/var/backups/automydumper'
backup_dir_format='+%F'
pre_dir='/usr/share/automydumper/pre.d'
post_dir='/usr/share/automydumper/post.d'
compress=1
keep=1
mysql_user='root'
mysql_password=''
mysql_host='localhost'
mysql_socket=
threads=4
mydumper_opts=''
enabled=1
use_savepoints=1
less_locking=1
backup_triggers=1
backup_events=1
backup_routines=1

version="1.3.1"

for cfg in "${HOME}/.automydumper.cfg" /etc/automydumper.cfg; do
    # Override defaults if config file is present
    if [ -f "${cfg}" ]; then
        source "${cfg}"
        export AUTOMYDUMPER_CFG_FILE="${cfg}"
        break
    fi
done

# Overwrite backup when a backup with the same name exists.
overwrite_backup=0

backup_dir_format="${backup_dir_format/ /}"

formatted_date="$(date ${backup_dir_format})"

backup_dir="${backup_root_dir}/${formatted_date}"
export AUTOMYDUMPER_BACKUP_ROOT="${backup_root_dir}"
export AUTOMYDUMPER_BACKUP_DIR="${backup_dir}"

# Set preliminary successful exitcode
export AUTOMYDUMPER_EXIT_CODE=0
export AUTOMYDUMPER_EXIT_MESSAGE=

mydumper_opts="${mydumper_opts} -o ${backup_dir} -v 3 --threads ${threads}"

[ ${compress} -eq 1 ] && mydumper_opts="${mydumper_opts} --compress"
[ ${use_savepoints} -eq 1 ] && mydumper_opts="${mydumper_opts} --use-savepoints"
[ ${less_locking} -eq 1 ] && mydumper_opts="${mydumper_opts} --less-locking"
[ ${backup_triggers} -eq 1 ] && mydumper_opts="${mydumper_opts} --triggers"
[ ${backup_events} -eq 1 ] && mydumper_opts="${mydumper_opts} --events"
[ ${backup_routines} -eq 1 ] && mydumper_opts="${mydumper_opts} --routines"

options=$(getopt -o h -o f --long help --long force -- "$@")
[ $? -eq 0 ] || {
    echo "Incorrect options provided"
    exit 1
}
eval set -- "$options"
while true; do
    case "$1" in
    --help|-h)
        echo ""
        echo "Automydumper ${version}"
        echo ""
        exit
        ;;
    --force|-f)
        overwrite_backup=1
        ;;
    --)
        shift
        break
        ;;
    esac
    shift
done

function mysql_credentials()
{
    echo -n "--user=${mysql_user} "

    if [ ! -z "${mysql_password}" ]; then
        echo -n "--password=${mysql_password} "
    fi

    if [ ! -z ${mysql_socket} ]; then
        echo -n "--socket=${mysql_socket}"
    else
        echo -n "--host=${mysql_host}"
    fi
}

function check_binaries()
{
    for binary in "$@"; do
        if ! which "${binary}" > /dev/null; then
            handle_error "${binary} not installed"
        fi
    done
}

function show_mydumper_version()
{
    echo "Note: Using $(mydumper --version | grep -i mydumper)"
}

function check_mysql_connection()
{
    if ! mysql $(mysql_credentials) -e 'select VERSION()' > /dev/null; then
        handle_error 'Wrong MySQL credentials or hostname/socket'
    fi
}

function cleanup_backups()
{
    [ ${AUTOMYDUMPER_EXIT_CODE} -gt 0 ] && return

    if [ ${keep} -eq 0 ]; then
        echo -e "Cleanup of old backups disabled because of keep=0\n"
        return
    fi

    while [ "$(find "${backup_root_dir}" -type f -name "metadata" | wc -l)" -gt "${keep}" ]; do
        oldest=$(find "${backup_root_dir}" -type f -name "metadata" -printf '%Cs %h\n' | sort | head -n 1 | awk '{ print $2}')
        echo "Deleting ${oldest}"
        rm -rf "${oldest}"
    done
    echo ""
}

function handle_error()
{
    export AUTOMYDUMPER_EXIT_CODE=1
    export AUTOMYDUMPER_EXIT_MESSAGE="${1}"
}

function run_commands()
{
    command_dir=${1}

    # Only run if command dir exists
    if [ ! -d ${command_dir} ]; then
        echo "Note: ${command_dir} does not exist, not searching for scripts to execute."
        return
    fi

    for cmd in $(find ${1} -maxdepth 1 -type f -executable); do
        if [ "${AUTOMYDUMPER_EXIT_CODE}" -eq 0 ]; then

            # Only run when the exit code is > 0 when tag below is found
            grep automydumper:run:on-error-only ${cmd} &> /dev/null && return

            echo "Note: Executing ${cmd}"
            echo "--- begin output ---"
            ${cmd} || handle_error "Command ${cmd} failed"
            echo "--- end output ---"
        else
            if grep -E "automydumper:run:(on-error-only|always)" ${cmd} &> /dev/null; then
                echo "Note: Executing ${cmd}"
                echo "--- begin output ---"
                ${cmd} || handle_error "Command ${cmd} failed"
                echo "--- end output ---"
            fi
        fi
    done
}

function overwrite_previous_backup()
{
    [ ${AUTOMYDUMPER_EXIT_CODE} -gt 0 ] && return

    if [ ${overwrite_backup} -eq 0 ]; then
        if [ -f "${backup_dir}/metadata" ]; then
            echo ""
            echo "Backup already exists, doing nothing."
            echo "Running automydumper with the '-f' or '--force' option will overwrite the previously taken backup."
            echo ""
            show_footer
            exit 0
        elif [ -f "${backup_dir}/metadata.partial" ]; then
            echo "Note: Deleting previous partial backup."
        fi
    else
      echo "Note: if a backup with the same name exists it will be forcefully removed"
    fi

    find "${backup_dir}" -mindepth 1 \( ! -iname "automydumper.log" \) -delete

    # Remove broken latest symlink if backup it's pointing to is no longer there.
    [ ! -e "${backup_root_dir}/latest" ] && rm -f "${backup_root_dir}/latest"
}

function symlink_latest()
{
    rm -f "${backup_root_dir}/latest"
    ln -sfr "${backup_dir}" "${backup_root_dir}/latest"
}

function run_mydumper()
{
    [ ${AUTOMYDUMPER_EXIT_CODE} -gt 0 ] && return

    mydumper_opts="${mydumper_opts} $(mysql_credentials)"
    if mydumper ${mydumper_opts}; then
        symlink_latest
    else
        handle_error "Mydumper could not complete backup"
    fi
}

function show_header()
{
    echo -e "\nAutomydumper version ${version}\n"
    echo "Started at `date`"
    echo ""
    [ -z ${AUTOMYDUMPER_CFG_FILE} ] || echo "Note: Using ${AUTOMYDUMPER_CFG_FILE} to override defaults."
}

function show_footer()
{
    if [ ${AUTOMYDUMPER_EXIT_CODE} -gt 0 ]; then
        echo ""
        echo "Critical: ${AUTOMYDUMPER_EXIT_MESSAGE}. Quitting."
    else
        echo "Finished at `date`"
    fi
}

function validate_date_format()
{
    # Make sure only valid chars are there
    if ! echo ${formatted_date} | grep -Eq '^[a-zA-Z0-9_:-]+$' &> /dev/null; then
        show_header
        echo "Critical: date as set in backup_dir_format parameter can only contain numbers, letters, '-', ':' or '_'."
        exit 1
    fi
}

# Stop the script when it's disabled by the user.
if [ $enabled -eq 0 ]; then
    echo "Automydumper is disabled. Enable by removing enabled=0. Quitting without action."
    exit 0
fi

trap "{ echo '!! Script interrupted.'; handle_error 'Backup interrupted'; }" INT

validate_date_format

# Make sure backup directory exists
mkdir -p "${backup_dir}"

# Remove the log before we restart the logging when we're overwriting the backup.
[ ${overwrite_backup} -eq 1 ] && rm -f "${backup_dir}/automydumper.log"

exec > >(tee -ia "${backup_dir}/automydumper.log")
exec 2>&1

show_header

check_binaries mysql mydumper
show_mydumper_version
check_mysql_connection

overwrite_previous_backup

run_commands ${pre_dir}

run_mydumper

run_commands ${post_dir}

cleanup_backups

show_footer

exit ${AUTOMYDUMPER_EXIT_CODE}