Startup MySQL

mysql12f.sh

#!/bin/bash

set -e -u -o pipefail

PWD=`pwd`
WHOAMI=`whoami`

BASEDIR=${MYSQL_SERVER_BASEDIR?missing MYSQL_SERVER_BASEDIR}

# default directories are subdirectories of where this script was run from
DATADIR=${MYSQL_SERVER_DATADIR:-${PWD}/data}
LOGDIR=${MYSQL_SERVER_DATADIR:-${PWD}/log}
RUNDIR=${MYSQL_SERVER_RUNDIR:-${PWD}/run}
TMPDIR=${MYSQL_SERVER_RUNDIR:-${PWD}/tmp}
SLAVELOADDIR=${MYSQL_SERVER_RUNDIR:-${PWD}/loaddata}

SOCKET=${MYSQL_SERVER_FILE_SOCK:-${RUNDIR}/mysql.sock}
PID=${MYSQL_SERVER_FILE_PID:-${RUNDIR}/mysql.pid}

LOGOUT=${MYSQL_SERVER_FILE_LOG:-${LOGDIR}/out.log}
LOGERR=${MYSQL_SERVER_FILE_ERR:-${LOGDIR}/out.err}

USER=${MYSQL_SERVER_USER:-${WHOAMI}}

# TODO: check if dirs / files exist and belong to the user, else...
# setup new ones - and init the db base tables!

mkdir -p "$DATADIR" "$LOGDIR" "$RUNDIR" "$TMPDIR" "$SLAVELOADDIR"
chown "$USER" "$DATADIR" "$LOGDIR" "$RUNDIR" "$TMPDIR" "$SLAVELOADDIR"

# direct output to stderr
[ -f "$LOGOUT" ] || ln -s /dev/stdout "${LOGOUT}"
[ -f "$LOGERR" ] || ln -s /dev/stderr "${LOGERR}"

su -m "$USER" -c mysqld --defaults-file=<(cat <<-MYSQLD_CONFIG
	[mysqld]
	basedir				= ${BASEDIR}
	datadir				= ${DATADIR}

	socket				= ${SOCKET}
	pid_file			= ${PID}

	tmpdir				= ${TMPDIR}

	slave_load_tmpdir	= ${SLAVELOADDIR}

	log_error			= ${LOGERR}
	general_log_file	= ${LOGOUT}
MYSQLD_CONFIG
)

totally untested partial conversion of a holy mess to a 12 factor app

uses [http://www.tldp.org/LDP/abs/html/parameter-substitution.html](BASH parameter substition), HEREDOC and redirection to generate a temporary config file on the fly from environment variables.