Thanks to a fun and productive weekend in Philadelphia with Nathan, I've finally written a script with which to perform regular backups of the important goodies from my server. Scheduling this to run regularly is left as an exercise for the reader, as is the decision of what to do with the tarballs so as to make the whole thing worthwhile. The script itself goes like so:

#!/bin/sh

BACKUP_IDENTIFIER="`hostname`"
BACKUP_STASH_SUBDIR="backups"
DEFAULT_TASKS="home mysql etc"
HOME_EXCLUDE_SUBDIRS="${BACKUP_STASH_SUBDIR} builds netbsd .netbsd"
ETC_DIRS="/etc /var/backups /var/cron /var/mysql"
MYSQL_DATABASES="schmonz schmonz_smf schmonz_textpattern"
MYSQL_USER="XXX"
MYSQL_PASS="XXX"

backup_home()
{
        local tarball find_prune
        tarball="$1"
        find_prune="-path ''"
        for i in ${HOME_EXCLUDE_SUBDIRS}; do
                find_prune="${find_prune} -o -path ./$i"
        done
        cd && find . \( ${find_prune} \) -prune -o \! -type d -print \
          | pax -wzf ${tarball} || die 1 "find/pax trouble"
}

backup_mysql()
{
        local tarball sqlfile
        tarball="$1"
        sqlfile=`basename ${tarball} .tar.gz`.sql
        cd ~/${BACKUP_STASH_SUBDIR}
        mysqldump --opt -u${MYSQL_USER} -p${MYSQL_PASS} --databases \
          ${MYSQL_DATABASES} > ${sqlfile} || die 2 "mysqldump trouble"
        pax -wzf ${tarball} ${sqlfile} || die 3 "pax trouble"
        rm ${sqlfile}
}

backup_etc()
{
        local tarball
        tarball="$1"
        sudo pax -wzf ${tarball} ${ETC_DIRS} || die 4 "pax trouble"
}

get_backup_tarball_path()
{
        local task
        task="$1"
        echo ~/${BACKUP_STASH_SUBDIR}/`date '+%Y%m%d'`-${BACKUP_IDENTIFIER}-${task}.tar.gz
}

die()
{
        local exitcode
        exitcode=$0; shift
        echo >&2 "error: $@"
        exit ${exitcode}
}

main()
{
        local tasks tarball_path
        tasks=${DEFAULT_TASKS}
        [ $# -gt 0 ] && tasks="$@"
        for i in ${tasks}; do
                tarball_path=`get_backup_tarball_path $i`
                echo backup_$i:
                backup_$i ${tarball_path}
                echo '  '${tarball_path}
        done
}

main "$@"
exit $?