acct-group.eclass: A new eclass to maintain group accounts

A GLEP 81-compliant eclass to create group packages.

Signed-off-by: Michał Górny <[email protected]>

eclass/acct-group.eclass

@@ -0,0 +1,124 @@
+# Copyright 2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# @ECLASS: acct-group.eclass
+# @MAINTAINER:
+# Michał Górny <[email protected]>
+# @AUTHOR:
+# Michael Orlitzky <[email protected]>
+# Michał Górny <[email protected]>
+# @BLURB: Eclass used to create and maintain a single group entry
+# @DESCRIPTION:
+# This eclass represents and creates a single group entry.  The name
+# of the group is derived from ${PN}, while (preferred) GID needs to
+# be specified via ACCT_GROUP_ID.  Packages (and users) needing the group
+# in question should depend on the package providing it.
+#
+# Example:
+# If your package needs group 'foo', you create 'acct-group/foo' package
+# and add an ebuild with the following contents:
+#
+# @CODE
+# EAPI=7
+# inherit acct-group
+# ACCT_GROUP_ID=200
+# @CODE
+#
+# Then you add appropriate dependency to your package.  The dependency
+# type(s) should be:
+# - DEPEND (+ RDEPEND) if the group is already needed at build time,
+# - RDEPEND if it is needed at install time (e.g. you 'fowners' files
+#   in pkg_preinst) or run time.
+
+if [[ -z ${_ACCT_GROUP_ECLASS} ]]; then
+_ACCT_GROUP_ECLASS=1
+
+case ${EAPI:-0} in
+	7) ;;
+	*) die "EAPI=${EAPI} not supported";;
+esac
+
+inherit user
+
+[[ ${CATEGORY} == acct-group ]] ||
+	die "Ebuild error: this eclass can be used only in acct-group category!"
+
+
+# << Eclass variables >>
+
+# @ECLASS-VARIABLE: ACCT_GROUP_NAME
+# @INTERNAL
+# @DESCRIPTION:
+# The name of the group.  This is forced to ${PN} and the policy
+# prohibits it from being changed.
+ACCT_GROUP_NAME=${PN}
+readonly ACCT_GROUP_NAME
+
+# @ECLASS-VARIABLE: ACCT_GROUP_ID
+# @REQUIRED
+# @DESCRIPTION:
+# Preferred GID for the new group.  This variable is obligatory, and its
+# value must be unique across all group packages.
+
+# @ECLASS-VARIABLE: ACCT_GROUP_ENFORCE_ID
+# @DESCRIPTION:
+# If set to a non-null value, the eclass will require the group to have
+# specified GID.  If the group already exists with another GID, or
+# the GID is taken by another group, the install will fail.
+: ${ACCT_GROUP_ENFORCE_ID:=}
+
+
+# << Boilerplate ebuild variables >>
+: ${DESCRIPTION:="System group: ${ACCT_GROUP_NAME}"}
+: ${HOMEPAGE:=https://www.gentoo.org/}
+: ${SLOT:=0}
+: ${KEYWORDS:=alpha amd64 arm arm64 hppa ia64 m68k ~mips ppc ppc64 ~riscv s390 sh sparc x86 ~ppc-aix ~x64-cygwin ~amd64-fbsd ~x86-fbsd ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~m68k-mint ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris}
+S=${WORKDIR}
+
+
+# << Phase functions >>
+EXPORT_FUNCTIONS pkg_pretend pkg_preinst
+
+# @FUNCTION: acct-group_pkg_pretend
+# @DESCRIPTION:
+# Performs sanity checks for correct eclass usage, and early-checks
+# whether requested GID can be enforced.
+acct-group_pkg_pretend() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	# verify ACCT_GROUP_ID
+	[[ -n ${ACCT_GROUP_ID} ]] || die "Ebuild error: ACCT_GROUP_ID must be set!"
+	[[ ${ACCT_GROUP_ID} -ge 0 ]] || die "Ebuild errors: ACCT_GROUP_ID=${ACCT_GROUP_ID} invalid!"
+
+	# check for ACCT_GROUP_ID collisions early
+	if [[ -n ${ACCT_GROUP_ENFORCE_ID} ]]; then
+		local group_by_id=$(egetgroupname "${ACCT_GROUP_ID}")
+		local group_by_name=$(egetent group "${ACCT_GROUP_NAME}")
+		if [[ -n ${group_by_id} ]]; then
+			if [[ ${group_by_id} != ${ACCT_GROUP_NAME} ]]; then
+				eerror "The required GID is already taken by another group."
+				eerror "  GID: ${ACCT_GROUP_ID}"
+				eerror "  needed for: ${ACCT_GROUP_NAME}"
+				eerror "  current group: ${group_by_id}"
+				die "GID ${ACCT_GROUP_ID} taken already"
+			fi
+		elif [[ -n ${group_by_name} ]]; then
+			eerror "The requested group exists already with wrong GID."
+			eerror "  groupname: ${ACCT_GROUP_NAME}"
+			eerror "  requested UID: ${ACCT_GROUP_ID}"
+			eerror "  current entry: ${group_by_name}"
+			die "Group ${ACCT_GROUP_NAME} exists with wrong GID"
+		fi
+	fi
+}
+
+# @FUNCTION: acct-group_pkg_preinst
+# @DESCRIPTION:
+# Creates the group if it does not exist yet.
+acct-group_pkg_preinst() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	enewgroup -F "${ACCT_GROUP_NAME}" "${ACCT_GROUP_ID}"
+}
+
+fi