devtools: add dist-tarball.sh

This patch adds a new devtool called dist-tarball.sh that creates a
reproducible xz-compressed tarball from a cloned git repository.

devtools/dist-tarball.sh

@@ -0,0 +1,129 @@
+#!/usr/bin/env bash
+#   BAREOS® - Backup Archiving REcovery Open Sourced
+#
+#   Copyright (C) 2021-2021 Bareos GmbH & Co. KG
+#
+#   This program is Free Software; you can redistribute it and/or
+#   modify it under the terms of version three of the GNU Affero General Public
+#   License as published by the Free Software Foundation and included
+#   in the file LICENSE.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+#   Affero General Public License for more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with this program; if not, write to the Free Software
+#   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+#   02110-1301, USA.
+
+set -e
+set -u
+
+# We need our environment so that
+#  * sort uses binary sort order
+#  * all timestamps are treated as UTC
+LANG=C
+TZ=UTC
+export LANG TZ
+
+cleanup_version_files=0
+at_exit() {
+  if [ "$cleanup_version_files" -gt 0 ]; then
+    rm -f cmake/BareosVersion.cmake
+  fi
+}
+trap at_exit EXIT
+
+git="${GIT:-$(command -v git)}"
+cmake="${CMAKE:-$(command -v cmake)}"
+
+# As we use extended features of GNU tar and the -z option from GNU sort, we
+# check if gtar/gsort are available and prefer them over tar/sort
+if [ -n "${TAR:-}" ]; then
+  tar="$TAR"
+else
+  for cmd in gtar tar; do
+    tar="$(command -v "$cmd" || :)"
+    [ -n "$tar" ] && break
+  done
+fi
+
+if [ -n "${SORT:-}" ]; then
+  sort="$SORT"
+else
+  for cmd in gsort sort; do
+    sort="$(command -v "$cmd" || :)"
+    [ -n "$sort" ] && break
+  done
+fi
+
+md5sum="$(command -v md5sum || :)"
+md5cmd="$(command -v md5 || :)"
+if [ -n "${md5sum}" ]; then
+  list_file_cmd=( "$md5sum" --tag --binary )
+elif [ -n "${md5cmd}" ]; then
+  list_file_cmd=( "${md5cmd}" )
+else
+  list_file_cmd=( ls -l )
+fi
+
+if ! xz="$(command -v xz)"; then
+  echo "Cannot find »xz« compressor executable." >&2
+  exit 2
+fi
+
+# The directory we're going to pack up
+topdir="$(dirname "$0")/.."
+
+# The directory where the tarball will be written to
+destdir=${1:-/tmp}
+if [ ! -d "${destdir}" ]; then
+  echo "Not a directory $destdir" >&2
+  exit 1
+fi
+
+abs_destdir="$(realpath "${destdir}")"
+
+pushd "${topdir}" >/dev/null
+
+changed_files="$("$git" diff --name-only; "$git" diff --name-only --cached)"
+
+if [ -n "${changed_files}" ]; then
+  echo "You have modified/deleted files in your working-copy" >&2
+  "$sort" -u <<< "${changed_files}"
+  exit 2
+fi
+
+# get version of Bareos to name tarball and directory
+version="$("$cmake" -P get_version.cmake | sed -e 's/^-- //')"
+# get timestamp of latest commit to use as mtime for all files in tarball
+timestamp="$("$git" show --quiet --date='format-local:%Y-%m-%d %H:%M:%S' --format='%cd')"
+
+basename="bareos-${version}"
+archive_file="${abs_destdir}/${basename}.tar.xz"
+
+args=(--transform "s#^./#${basename}/#" \
+      --format=ustar \
+      --numeric-owner \
+      --owner=0 \
+      --group=0 \
+      --mode="go-w" \
+      "--mtime=$timestamp" \
+      --null \
+      --no-recursion \
+    )
+
+if [ ! -r cmake/BareosVersion.cmake ]; then
+  cleanup_version_files=1
+  cmake -P write_version_files.cmake >/dev/null
+fi
+
+(echo -ne 'cmake/BareosVersion.cmake\0'; "$git" ls-files -z) | \
+"$sort" -u -z | \
+"$tar" "${args[@]}" -cf - --files-from - | \
+"$xz" -c -6 > "${archive_file}"
+
+echo -n "Wrote tarball: "
+"${list_file_cmd[@]}" "${archive_file}"