Break out RPM version logic from RPM build script

In order to determine what RPM package version would be built from a
given commit, the logic for determining the version needs to be split
out from the script that builds RPMs.

Now, if you are going to use `hack/build-rpm-release.sh` you can first
call `os::build::rpm::format_nvr` to determine the NVR of the package
you will build.

Signed-off-by: Steve Kuznetsov <[email protected]>

Author: stevekuznetsov

hack/build-rpm-release.sh

@@ -17,19 +17,9 @@ else
 fi
 
 os::log::info 'Building Origin release RPMs with tito...'
-os::build::get_version_vars
-if [[ "${OS_GIT_TREE_STATE}" == "dirty" ]]; then
-	os::log::fatal "Cannot build RPMs with a dirty git tree. Commit your changes and try again."
-fi
-if [[ "${OS_GIT_VERSION}" =~ ^v([0-9](\.[0-9]+)*)(.*) ]]; then
-	# we need to translate from the semantic version
-	# provided by the Origin build scripts to the
-	# version that RPM will expect.
-	rpm_version="${BASH_REMATCH[1]}"
-	rpm_release="999${BASH_REMATCH[3]//-/.}"
-fi
-tito tag --use-version="${rpm_version}" \
-         --use-release="${rpm_release}" \
+os::build::rpm::get_nvr_vars
+tito tag --use-version="${OS_RPM_VERSION}" \
+         --use-release="${OS_RPM_RELEASE}" \
          --no-auto-changelog --offline
 tito_tmp_dir="${BASETMPDIR}/tito"
 mkdir -p "${tito_tmp_dir}"
@@ -56,7 +46,7 @@ else
 	output_directory="${output_directories[0]}"
 fi
 
-tito_output_directory="$( find "${output_directory}" -type d -path "*/BUILD/origin-${rpm_version}/_output/local" )"
+tito_output_directory="$( find "${output_directory}" -type d -path "*/BUILD/origin-${OS_RPM_VERSION}/_output/local" )"
 if [[ -z "${tito_output_directory}" ]]; then
         os::log::fatal 'No _output artifact directory found in tito rpmbuild artifacts!'
 fi

hack/lib/build/rpm.sh

@@ -0,0 +1,82 @@
+#!/bin/bash
+
+# This library holds utilities for building RPMs from Origin.
+
+# os::build::rpm::generate_nevra_vars determines the NEVRA of the RPMs
+# that would be built from the current git state.
+#
+# Globals:
+#  - OS_GIT_VERSION
+# Arguments:
+#  - None
+# Exports:
+#  - OS_RPM_NAME
+#  - OS_RPM_VERSION
+#  - OS_RPM_RELEASE
+function os::build::rpm::get_nvr_vars() {
+	# the package name can be overwritten but is normally 'origin'
+	OS_RPM_NAME="${OS_RPM_NAME:-"origin"}"
+
+	# we can extract the pacakge version from the build version
+	os::build::get_version_vars
+	if [[ "${OS_GIT_VERSION}" =~ ^v([0-9](\.[0-9]+)*)(.*) ]]; then
+		OS_RPM_VERSION="${BASH_REMATCH[1]}"
+		metadata="${BASH_REMATCH[3]}"
+	else
+		os::log::fatal "Malformed \$OS_GIT_VERSION: ${OS_GIT_VERSION}"
+	fi
+
+	# we can generate the package release from the git version metadata
+	# OS_GIT_VERSION will always have metadata, but either contain
+	# pre-release information _and_ build metadata, or only the latter
+	# ex.
+	#    -alpha.0+shasums-123-dirty
+	#    -alpha.0+shasums-123
+	#    +shasums-123-dirty
+	#    +shasums-123
+	if [[ "${metadata:0:1}" == "+" ]]; then
+		# we only have build metadata, but need to massage it so
+		# we can generate a valid RPM release from it
+		if [[ "${metadata}" =~ ^\+([a-z0-9]{7})-([0-9]+)(-dirty)?$ ]]; then
+			build_sha="${BASH_REMATCH[1]}"
+			build_num="${BASH_REMATCH[2]}"
+		else
+			os::log::fatal "Malformed git version metadata: ${metadata}"
+		fi
+		OS_RPM_RELEASE="1.${build_num}.${build_sha}"
+	elif [[ "${metadata:0:1}" == "-" ]]; then
+		# we have both build metadata and pre-release info
+		if [[ "${metadata}" =~ ^-([^\+]+)\+([a-z0-9]{7})-([0-9]+)(-dirty)?$ ]]; then
+			pre_release="${BASH_REMATCH[1]}"
+			build_sha="${BASH_REMATCH[2]}"
+			build_num="${BASH_REMATCH[3]}"
+		else
+			os::log::fatal "Malformed git version metadata: ${metadata}"
+		fi
+		OS_RPM_RELEASE="0.${pre_release}.${build_num}.${build_sha}"
+	else
+		os::log::fatal "Malformed git version metadata: ${metadata}"
+	fi
+
+	export OS_RPM_NAME OS_RPM_VERSION OS_RPM_RELEASE
+}
+
+
+# os::build::rpm::format_nvr formats the rpm NVR vars generated by
+# os::build::rpm::get_nvr_vars and will generate them if necessary
+#
+# Globals:
+#  - OS_RPM_NAME
+#  - OS_RPM_VERSION
+#  - OS_RPM_RELEASE
+# Arguments:
+#  None
+# Returns:
+#  None
+function os::build::rpm::format_nvr() {
+	if [[ -z "${OS_RPM_NAME:-}" || -z "${OS_RPM_VERSION:-}" || -z "${OS_RPM_RELEASE:-}" ]]; then
+		os::build::rpm::get_nvr_vars
+	fi
+
+	echo "${OS_RPM_NAME}-${OS_RPM_VERSION}-${OS_RPM_RELEASE}"
+}