[skip-ci] Makefile: update rpm target

rpkg is now deprecated. This commit makes the rpm target consistent with
the one in Podman.

Using skip-ci as we don't need to run cirrus tests for this change.

Signed-off-by: Lokesh Mandvekar <lsm5@redhat.com>

Makefile

@@ -218,5 +218,13 @@ lint: install.tools
 # CAUTION: This is not a replacement for RPMs provided by your distro.
 # Only intended to build and test the latest unreleased changes.
 .PHONY: rpm
-rpm:
-	rpkg local
+rpm:  ## Build rpm packages
+	$(MAKE) -C rpm
+
+# Remember that rpms install exec to /usr/bin/buildah while a `make install`
+# installs them to /usr/local/bin/buildah which is likely before. Always use
+# a full path to test installed buildah or you risk to call another executable.
+.PHONY: rpm-install
+rpm-install: package  ## Install rpm packages
+	$(call err_if_empty,PKG_MANAGER) -y install rpm/RPMS/*/*.rpm
+	/usr/bin/buildah version

rpm/Makefile

@@ -0,0 +1,12 @@
+.PHONY: rpm
+rpm:
+	$(shell /usr/bin/bash ./update-spec-version.sh)
+	spectool -g buildah.spec
+	rpmbuild -ba \
+		--define '_sourcedir $(shell pwd)' \
+		--define '_rpmdir %{_sourcedir}/RPMS' \
+		--define '_srcrpmdir %{_sourcedir}/SRPMS' \
+		--define '_builddir %{_sourcedir}/BUILD' \
+		buildah.spec
+	@echo ___RPMS can be found in rpm/RPMS/.___
+	@echo ___Undo any changes to Version, Source0 and %autosetup in rpm/buildah.spec before committing.___

rpm/update-spec-version.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+# This script will update the Version field in the spec which is set to 0 by
+# default. Useful for local manual rpm builds where the Version needs to be set
+# correctly.
+
+set -eox pipefail
+
+PACKAGE=buildah
+SPEC_FILE=$PACKAGE.spec
+VERSION=$(grep 'Version = ' ../define/types.go | cut -d\" -f2)
+RPM_VERSION=$(echo $VERSION | sed -e 's/^v//' -e 's/-/~/g')
+
+# Update spec file to use local changes
+sed -i "s/^Version:.*/Version: $RPM_VERSION/" $SPEC_FILE
+sed -i "s/^Source:.*/Source: $PACKAGE-$VERSION.tar.gz/" $SPEC_FILE
+sed -i "s/^%autosetup.*/%autosetup -Sgit -n %{name}-$VERSION/" $SPEC_FILE
+
+# Generate Source0 archive from HEAD
+(cd .. && git archive --format=tar.gz --prefix=$PACKAGE-$VERSION/ HEAD -o rpm/$PACKAGE-$VERSION.tar.gz)