guru/eclass/databases.eclass

# Copyright 2022 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: databases.eclass
# @MAINTAINER:
# Anna <cyber+gentoo@sysrq.in>
# @AUTHOR:
# Anna <cyber+gentoo@sysrq.in>
# @SUPPORTED_EAPIS: 8
# @BLURB: eclass to test packages against databases
# @DESCRIPTION:
# A utility eclass providing functions for running databases.
#
# This eclass does not set any metadata variables nor export any phase, so it
# can be inherited safely.
#
# @SUBSECTION Supported databases
#
# - memcached (via "ememcached" helper)
#
# - MongoDB (via "emongod" helper)
#
# - MySQL/MariaDB/ (via "emysql" helper)
#
# - PostgreSQL (via "epostgres" helper)
#
# - Redis (via "eredis" helper)
#
# @SUBSECTION Helper usage
#
# --die [msg]
#
#	Prints the path to the server's log file to the console and aborts the
#	current merge process with the given message.
#
# --get-dbpath
#
# 	Returns the directory where the server stores database files.
#
# --get-depend [use1,use2,...]
#
# 	Returns a dependency string (to be included in BDEPEND).
#
# --get-logfile
#
# 	Returns the path to the server's log file.
#
# --get-pidfile
#
# 	Returns the path to the server's PID file.
#
# --get-sockdir
#
# 	Returns the directory where the server's sockets are located.
#
# --get-sockfile
#
# 	Returns the path to the server's socket file.
#
# --start
#
# 	Starts the server on the default port.
#
# --start <port>
#
# 	Starts the server on the given port.
#
# --stop
#
# 	Stops the server.
#
# @EXAMPLE:
#
# @CODE
# EAPI=8
#
# ...
#
# inherit databases distutils-r1
#
# ...
#
# BDEPEND="$(eredis --get-depend)"
#
# distutils_enable_tests pytest
#
# src_test() {
# 	eredis --start 16739
# 	distutils-r1_src_test
# 	eredis --stop
# }
# @CODE

case ${EAPI} in
	8) ;;
	*) die "${ECLASS}: EAPI ${EAPI} unsupported."
esac

if [[ ! ${_DATABASES_ECLASS} ]]; then
_DATABASES_ECLASS=1

# ==============================================================================
# GENERIC FUNCTIONS
# ==============================================================================

# @FUNCTION: _databases_gen_depend
# @USAGE: <funcname> <required use>
# @INTERNAL
# @DESCRIPTION:
# Get a dependency string for the given helper function.
_databases_gen_depend() {
	local srvname=${1:1}
	local req_use=${2}

	local pkg_dep
	case ${srvname} in
		memcached)
			pkg_dep="net-misc/memcached"
			;;
		mongod)
			pkg_dep="dev-db/mongodb"
			;;
		mysql)
			pkg_dep="virtual/mysql"
			req_use="server,${req_use}"
			;;
		postgres)
			pkg_dep="dev-db/postgresql"
			req_use="server,${req_use}"
			;;
		redis)
			pkg_dep="dev-db/redis"
			;;
		*)
			die "${ECLASS}: unknown database: ${srvname}"
	esac

	req_use=${req_use%,}  # strip trailing comma
	printf "%s" "${pkg_dep}"
	[[ ${req_use} ]] && \
		printf "[%s]" "${req_use}"
}

# @FUNCTION: _databases_die
# @USAGE: <funcname> [msg]
# @INTERNAL
# @DESCRIPTION:
# Print the given message and the path to the server's log file to the console
# and die.
#
# This function supports being called via "nonfatal".
_databases_die() {
	local funcname=${1?}
	shift

	eerror "See the server log for details:"
	eerror "	$(${funcname} --get-logfile)"
	die -n "${@}"
}

# @FUNCTION: _databases_stop_service
# @USAGE: <funcname>
# @INTERNAL
# @DESCRIPTION:
# Default function to stop servers.  Reads PID from a file and sends the TERM
# signal.
_databases_stop_service() {
	debug-print-function "${FUNCNAME}" "${@}"

	local funcname=${1?}
	local srvname=${funcname:1}
	local pidfile="$(${funcname} --get-pidfile)"

	ebegin "Stopping ${srvname}"
	kill "$(<"${pidfile}")"
	eend $? || ${funcname} --die "Stopping ${srvname} failed"
}

# @FUNCTION: _databases_dispatch
# @USAGE: <funcname> <cmd> [args...]
# @INTERNAL
# @DESCRIPTION:
# Process the given command with its options.
#
# If "--start" command is used, `_${funcname}_start` function must be defined.
# Note that directories will be created automatically.
#
# If `_${funcname}_stop` function is not declared, the internal
# `_databases_stop_service` function will be used instead.
#
# No `--get` function can be overloaded.
_databases_dispatch() {
	local funcname=${1?}
	local cmd=${2?}
	shift; shift

	case ${cmd} in
		--die)
			_databases_die ${funcname} "${@}"
			;;
		--get-depend)
			_databases_gen_depend ${funcname} "${@}"
			;;
		--get-dbpath)
			echo "${T}"/${funcname}/db/
			;;
		--get-logfile)
			echo "${T}"/${funcname}/${funcname}.log
			;;
		--get-pidfile)
			echo "${T}"/${funcname}/${funcname}.pid
			;;
		--get-sockdir)
			echo "${T}"/${funcname}/
			;;
		--get-sockfile)
			echo "${T}"/${funcname}/${funcname}.sock
			;;
		--start)
			local port=${1}
			local start_fn=( _${funcname}_start ${port} )
			if ! declare -f "${start_fn[0]}" >/dev/null; then
				die "${ECLASS}: function not declared: ${start_fn[0]}"
			fi

			mkdir -p "${T}"/${funcname}/db/ || die "Creating database directory failed"
			"${start_fn[@]}"
			;;
		--stop)
			local stop_fn=( _${funcname}_stop )
			if ! declare -f "${stop_fn[0]}" >/dev/null; then
				# fall back to the default implementation
				stop_fn=( _databases_stop_service ${funcname} )
			fi

			"${stop_fn[@]}"
			;;
		*) die "${funcname}: invalid command: ${cmd}" ;;
	esac
}

# ==============================================================================
# MEMCACHED
# ==============================================================================

# @FUNCTION: _ememcached_start
# @USAGE: [port]
# @INTERNAL
# @DESCRIPTION:
# Start memcached server.
_ememcached_start() {
	debug-print-function "${FUNCNAME}" "${@}"

	local port=${1:-11211}

	local myargs=(
		--daemon
		--port=${port}
		--user=nobody
		--listen=127.0.0.1
		--pidfile=$(ememcached --get-pidfile)
	)

	ebegin "Spawning memcached"
	memcached "${myargs[@]}" &>> $(ememcached --get-logfile)
	eend $? || ememcached --die "Spawning memcached failed"
}

# @FUNCTION: ememcached
# @USAGE: <cmd> [args...]
# @DESCRIPTION:
# Manage memcached server on the given port (default: 11211).
ememcached() {
	_databases_dispatch "${FUNCNAME}" "${@}"
}

# ==============================================================================
# MONGODB
# ==============================================================================

# @FUNCTION: _emongod_start
# @USAGE: [port]
# @INTERNAL
# @DESCRIPTION:
# Start MongoDB server.
_emongod_start() {
	debug-print-function "${FUNCNAME}" "${@}"

	local port=${1:-27017}
	local logfile=$(emongod --get-logfile)

	local myargs=(
		--dbpath="$(emongod --get-dbpath)"
		--nojournal
		--bind-ip=127.0.0.1
		--port=${port}
		--unixSocketPrefix="$(emongod --get-sockdir)"
		--logpath="${logfile}"
		--fork
	)

	ebegin "Spawning mongodb"
	LC_ALL=C mongod "${myargs[@]}" &>> "${logfile}"
	eend $? || emongod --die "Spawning mongod failed"
}

# @FUNCTION: _emongod_stop
# @INTERNAL
# @DESCRIPTION:
# Stop MongoDB server.
_emongod_stop() {
	debug-print-function "${FUNCNAME}" "${@}"

	local myargs=(
		--dbpath="$(emongod --get-dbpath)"
		--shutdown
	)

	ebegin "Stopping mongodb"
	mongod "${myargs[@]}" &>> "${logfile}"
	eend $? || emongod --die "Stopping mongod failed"
}

# @FUNCTION: emongod
# @USAGE: <cmd> [args...]
# @DESCRIPTION:
# Manage MongoDB server on the given port (default: 27017).
emongod() {
	_databases_dispatch "${FUNCNAME}" "${@}"
}

# ==============================================================================
# MYSQL
# ==============================================================================

# @FUNCTION: _emysql_start
# @USAGE: [port]
# @INTERNAL
# @DESCRIPTION:
# Create a new MySQL database and start MySQL server.
_emysql_start() {
	debug-print-function "${FUNCNAME}" "${@}"

	local port=${1:-3306}
	local dbpath=$(emysql --get-dbpath)
	local logfile=$(emysql --get-logfile)
	local sockfile=$(emysql --get-sockfile)

	local myinstallargs=(
		--no-defaults
		--auth-root-authentication-method=normal
		--basedir="${BROOT}/usr"
		--datadir="${dbpath}"
	)

	ebegin "Initializing mysql database"
	mysql_install_db "${myinstallargs[@]}" &>> "${logfile}"
	eend $? || emysql --die "Initializing mysql database failed"

	local myargs=(
		--no-defaults
		--character-set-server=utf8
		--pid-file="$(emysql --get-pidfile)"
		--socket="${sockfile}"
		--bind-address=127.0.0.1
		--port=${port}
		--datadir="${dbpath}"
		--general-log-file="${logfile}"
		--log-error="${logfile}"
	)

	einfo "Spawning mysql"
	mysqld "${myargs[@]}" &>> "${logfile}" &

	einfo "Waiting for mysqld to accept connections"
	local timeout=30
	while ! mysqladmin ping --socket="${sockfile}" --silent; do
		sleep 1
		let timeout-=1
		[[ ${timeout} -eq 0 ]] && emysql --die "Timed out"
	done
}

# @FUNCTION: emysql
# @USAGE: <cmd> [args...]
# @DESCRIPTION:
# Manage MySQL server on the given port (default: 3306).
emysql() {
	_databases_dispatch "${FUNCNAME}" "${@}"
}

# ==============================================================================
# POSTGRESQL
# ==============================================================================

# @FUNCTION: _epostgres_start
# @USAGE: [port]
# @INTERNAL
# @DESCRIPTION:
# Create a new PostgreSQL database and start PostgreSQL server.
_epostgres_start() {
	debug-print-function "${FUNCNAME}" "${@}"

	local port=${1:-5432}
	local dbpath=$(epostgres --get-dbpath)
	local logfile=$(epostgres --get-logfile)

	local myinstallargs=(
		--pgdata="${dbpath}"
		--user=postgres
	)

	ebegin "Initializing postgresql database"
	initdb "${myinstallargs[@]}" &>> "${logfile}"
	eend $? || epostgres --die "Initializing postgresql database failed"

	local myargs=(
		--pgdata="${dbpath}"
		--log="${logfile}"
		--options="-h '127.0.0.1' -p ${port} -k '$(epostgres --get-sockdir)'"
		--wait
	)

	ebegin "Spawning postgresql"
	pg_ctl "${myargs[@]}" start &>> "${logfile}"
	eend $? || epostgres --die "Spawning postgresql failed"
}

# @FUNCTION: _epostgres_stop
# @INTERNAL
# @DESCRIPTION:
# Stop PosgreSQL server.
_epostgres_stop() {
	debug-print-function "${FUNCNAME}" "${@}"

	local myargs=(
		--pgdata="$(epostgres --get-dbpath)"
		--wait
	)

	ebegin "Stopping postgresql"
	pg_ctl "${myargs[@]}" stop &>> "$(epostgres --get-logfile)"
	eend $? || epostgres --die "Stopping postgresql failed"
}

# @FUNCTION: epostgres
# @USAGE: <cmd> [args...]
# @DESCRIPTION:
# Manage PostgreSQL server on the given port (default: 5432).
epostgres() {
	_databases_dispatch "${FUNCNAME}" "${@}"
}

# ==============================================================================
# REDIS
# ==============================================================================

# @FUNCTION: _eredis_start
# @USAGE: [args...]
# @INTERNAL
# @DESCRIPTION:
# Start Redis server.
_eredis_start() {
	debug-print-function "${FUNCNAME}" "${@}"

	local port=${1:-6379}
	local logfile="$(eredis --get-logfile)"

	ebegin "Spawning redis"
	redis-server - <<- EOF &>> "${logfile}"
		daemonize yes
		pidfile "$(eredis --get-pidfile)"
		port ${port}
		bind 127.0.0.1
		unixsocket "$(eredis --get-sockfile)"
		dir "$(eredis --get-dbpath)"
		logfile "${logfile}"
	EOF
	eend $? || eredis --die "Spawning redis failed"
}

# @FUNCTION: eredis
# @USAGE: <cmd> [args...]
# @DESCRIPTION:
# Manage Redis server on the given port (default: 6379).
eredis() {
	_databases_dispatch "${FUNCNAME}" "${@}"
}

fi