admin/make-release.sh: automate release creation

This does the absolute bare minimum to produce a release.

This logic best resembles the expectations for legacy (pre-0.5) releases
of Lutok.

Various files are omitted as they are not required in order to build
from a full `autoreconf`'ed source distribution.

Signed-off-by: Enji Cooper <ngie@FreeBSD.org>

.gitignore

@@ -21,4 +21,5 @@ config.status
 configure
 libtool
 lutok.pc
+releases
 stamp-h1

admin/make-release.exclude

@@ -0,0 +1,11 @@
+*/.cirrus.yml
+*/.github/*
+*/.gitignore
+*/.travis.yml
+*/admin*
+*/autom4te.cache/*
+*/m4/libtool.m4
+*/m4/ltoptions.m4
+*/m4/ltsugar.m4
+*/m4/ltversion.m4
+*/m4/lt~obsolete.m4

admin/make-release.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+#
+# Create release artifacts from a release tag.
+#
+# Example:
+# 	./admin/make-release.sh atf-0.23
+
+set -eux
+
+tag=$1
+
+cd "$(dirname "$(dirname "$0")")"
+
+mkdir -p releases
+release_root=$(realpath releases)
+
+release_dir="${release_root}/${tag}"
+release_artifact="${release_root}/${tag}.tar.gz"
+
+rm -Rf "${release_dir}"
+mkdir -p "${release_dir}"
+git archive "${tag}" | tar xzvf - -C "${release_dir}"
+cd "${release_dir}"
+autoreconf -is
+cd "${release_root}"
+bsdtar \
+    --exclude-from=${release_dir}/admin/make-release.exclude \
+    --uname "" --gname "" \
+    --uid 0 --gid 0 \
+    -cvpzf "${release_artifact}" "${tag}"
+sha256 "${release_artifact##*/}" > "${release_artifact}.sha256"