rpmbuild: Add routine for generating a standalone rpm .spec

Signed-off-by: Michal Berger <michalx.berger@intel.com>
Change-Id: Ib8e139b928fd3e8cea67ebdc3ff1e464f51598bc
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8389
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Pawel Piatek <pawelx.piatek@intel.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-by: <tomasz.rochumski@intel.com>

autopackage.sh

@@ -32,6 +32,9 @@ function build_rpms() (
 	}
 
 	build_rpm() {
+		# Separate run to see the final .spec in use
+		GEN_SPEC=yes BUILDDIR=$builddir MAKEFLAGS="$MAKEFLAGS" SPDK_VERSION="$version" DEPS=no "$rootdir/rpmbuild/rpm.sh" "$@"
+		# Actual build
 		BUILDDIR=$builddir MAKEFLAGS="$MAKEFLAGS" SPDK_VERSION="$version" DEPS=no "$rootdir/rpmbuild/rpm.sh" "$@"
 		install_uninstall_rpms
 	}

rpmbuild/rpm.sh

@@ -65,8 +65,9 @@ get_version() {
 	echo "${version%%-*}"
 }
 
-build_rpm() (
-	local macros=() dir
+build_macros() {
+	local -g macros=()
+	local dir
 
 	macros+=(-D "configure ${configure:-"%{nil}"}")
 	macros+=(-D "make $make")
@@ -113,9 +114,13 @@ build_rpm() (
 		macros+=(-D "build_requirements 1")
 		macros+=(-D "build_requirements_list $build_requirements")
 	fi
+}
 
-	cd "$rootdir"
+gen_spec() {
+	rpmspec "${macros[@]}" -P "$spec"
+}
 
+build_rpm() (
 	fedora_python_sys_path_workaround
 
 	# Despite building in-place, rpmbuild still looks under source dir as defined
@@ -139,4 +144,9 @@ version=${SPDK_VERSION:-$(get_version)}
 rpmbuild_dir=${BUILDDIR:-"$HOME/rpmbuild"}
 spec=$specdir/spdk.spec
 
+build_macros
+if [[ -n $GEN_SPEC ]]; then
+	gen_spec
+	exit 0
+fi
 build_rpm