Initial commit postgres{,-multi}.eclass

postgres.eclass provides convenience functions that are commonly
performed in most packages that require PostgreSQL.

postgres-multi.eclass enables packages to build against all selected
PostgreSQL slots.

Added POSTGRES_TARGETS as a new USE_EXPAND variable to select which
slots are depended upon and built against.

1 files changed, 159 insertions, 0 deletions

diff --git a/eclass/postgres.eclass b/eclass/postgres.eclass
new file mode 100644
index 000000000000..6df81c19b3aa
--- /dev/null
+++ b/eclass/postgres.eclass
@@ -0,0 +1,159 @@
+# Copyright 1999-2016 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Id$
+
+inherit user
+EXPORT_FUNCTIONS pkg_setup
+
+# @ECLASS: postgres
+# @MAINTAINER:
+# PostgreSQL <pgsql-bugs@gentoo.org>
+# @AUTHOR: Aaron W. Swenson <titanofold@gentoo.org>
+# @BLURB: An eclass for PostgreSQL-related packages
+# @DESCRIPTION:
+# This eclass provides common utility functions that many
+# PostgreSQL-related packages perform, such as checking that the
+# currently selected PostgreSQL slot is within a range, adding a system
+# user to the postgres system group, and generating dependencies.
+
+
+case ${EAPI:-0} in
+	5|6) ;;
+	*) die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}" ;;
+esac
+
+
+# @ECLASS-VARIABLE: POSTGRES_COMPAT
+# @DESCRIPTION:
+# A Bash array containing a list of compatible PostgreSQL slots as
+# defined by the developer. If declared, must be declared before
+# inheriting this eclass. Example: POSTGRES_COMPAT=( 9.4 9.{5,6} )
+
+# @ECLASS-VARIABLE: POSTGRES_USEDEP
+# @DESCRIPTION:
+# Add the 2-Style and/or 4-Style use dependencies without brackets to be used
+# for POSTGRES_DEP. If declared, must be done before inheriting this eclass.
+
+# @ECLASS-VARIABLE: POSTGRES_DEP
+# @DESCRIPTION:
+# An automatically generated dependency string suitable for use in
+# DEPEND and RDEPEND declarations.
+
+# @ECLASS-VARIABLE: POSTGRES_REQ_USE
+# @DESCRIPTION:
+# An automatically generated REQUIRED_USE-compatible string built upon
+# POSTGRES_COMPAT. REQUIRED_USE="... ${POSTGRES_REQ_USE}" is only
+# required if the package must build against one of the PostgreSQL slots
+# declared in POSTGRES_COMPAT.
+
+if declare -p POSTGRES_COMPAT &> /dev/null ; then
+	# Reverse sort the given POSTGRES_COMPAT so that the most recent
+	# slot is preferred over an older slot.
+	# -- do we care if dependencies are deterministic by USE flags?
+	readarray -t POSTGRES_COMPAT < <(printf '%s\n' "${POSTGRES_COMPAT[@]}" | sort -nr)
+
+	POSTGRES_DEP=""
+	POSTGRES_REQ_USE=" || ("
+	for slot in "${POSTGRES_COMPAT[@]}" ; do
+		POSTGRES_DEP+=" postgres_targets_postgres${slot/\./_}? ( dev-db/postgresql:${slot}="
+		declare -p POSTGRES_USEDEP &>/dev/null && \
+			POSTGRES_DEP+="[${POSTGRES_USEDEP}]"
+		POSTGRES_DEP+=" )"
+
+		IUSE+=" postgres_targets_postgres${slot/\./_}"
+		POSTGRES_REQ_USE+=" postgres_targets_postgres${slot/\./_}"
+	done
+	POSTGRES_REQ_USE+=" )"
+else
+	POSTGRES_DEP="dev-db/postgresql:="
+	declare -p POSTGRES_USEDEP &>/dev/null && \
+		POSTGRES_DEP+="[${POSTGRES_USEDEP}]"
+fi
+
+
+# @FUNCTION: postgres_check_slot
+# @DESCRIPTION:
+# Verify that the currently selected PostgreSQL slot is set to one of
+# the slots defined in POSTGRES_COMPAT. Automatically dies unless a
+# POSTGRES_COMPAT slot is selected. Should be called in pkg_pretend().
+postgres_check_slot() {
+	if ! declare -p POSTGRES_COMPAT &>/dev/null; then
+		die 'POSTGRES_COMPAT not declared.'
+	fi
+
+	# Don't die because we can't run postgresql-config during pretend.
+	[[ "$EBUILD_PHASE" = "pretend" && -z "$(which postgresql-config 2> /dev/null)" ]] \
+		&& return 0
+
+	if has $(postgresql-config show 2> /dev/null) "${POSTGRES_COMPAT[@]}"; then
+		return 0
+	else
+		eerror "PostgreSQL slot must be set to one of: "
+		eerror "    ${POSTGRES_COMPAT[@]}"
+		die "Incompatible PostgreSQL slot eselected"
+	fi
+}
+
+# @FUNCTION: postgres_new_user
+# @DESCRIPTION:
+# Creates the "postgres" system group and user -- which is separate from
+# the database user -- in addition to the developer defined user. Takes
+# the same arguments as "enewuser".
+postgres_new_user() {
+	enewgroup postgres 70
+	enewuser postgres 70 /bin/bash /var/lib/postgresql postgres
+
+	if [[ $# -gt 0 ]] ; then
+		if [[ "$1" = "postgres" ]] ; then
+			ewarn "Username 'postgres' implied, skipping"
+		else
+			local groups=$5
+			[[ -n "${groups}" ]] && groups+=",postgres" || groups="postgres"
+			enewuser "$1" "${2:--1}" "${3:--1}" "${4:--1}" "${groups}"
+		fi
+	fi
+}
+
+# @FUNCTION: postgres_pkg_setup
+# @REQUIRED
+# @USAGE: postgres_pkg_setup
+# @DESCRIPTION:
+# Initialize environment variable(s) according to the best
+# installed version of PostgreSQL that is also in POSTGRES_COMPAT. This
+# is required if pkg_setup() is declared in the ebuild.
+# Exports PG_SLOT, PG_CONFIG, and PKG_CONFIG_PATH.
+postgres_pkg_setup() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local compat_slot
+	local best_slot
+	for compat_slot in "${POSTGRES_COMPAT[@]}"; do
+		if use "postgres_targets_postgres${compat_slot/\./_}"; then
+			best_slot="${compat_slot}"
+			break
+		fi
+	done
+
+	if [[ -z "${best_slot}" ]]; then
+		local flags f
+		for f in "${POSTGRES_COMPAT[@]}"; do
+			flags+=" postgres${f/./_}"
+		done
+
+		eerror "POSTGRES_TARGETS must contain at least one of:"
+		eerror "    ${flags}"
+		die "No suitable POSTGRES_TARGETS enabled."
+	fi
+
+	export PG_SLOT=${best_slot}
+	export PG_CONFIG=$(which pg_config${best_slot//./})
+
+	local pg_pkg_config_path="$(${PG_CONFIG} --libdir)/pkgconfig"
+	if [[ -n "${PKG_CONFIG_PATH}" ]]; then
+		export PKG_CONFIG_PATH="${pg_pkg_config_path}:${PKG_CONFIG_PATH}"
+	else
+		export PKG_CONFIG_PATH="${pg_pkg_config_path}"
+	fi
+
+	elog "PostgreSQL Target: ${best_slot}"
+}