print-current-version

#!/usr/bin/env python
#
# Print the value of `ostree.version` from the currently booted commit.
#
# Copyright 2015 Colin Walters <walters@verbum.org>
# Licensed under the new-BSD license (http://www.opensource.org/licenses/bsd-license.php)

from __future__ import print_function

import gi
gi.require_version('OSTree', '1.0')
from gi.repository import GLib, Gio, OSTree
import argparse

def fatal(msg):
    print >>sys.stderr, msg
    sys.exit(1)

parser = argparse.ArgumentParser(prog="print-current-version")
arg = parser.parse_args()

sysroot = OSTree.Sysroot.new_default()
sysroot.load(None)

_,repo = sysroot.get_repo(None)

deployment = sysroot.get_booted_deployment()
if deployment is None:
    fatal("Not in a booted OSTree system!")

commitid = deployment.get_csum()
_,commit = repo.load_variant(OSTree.ObjectType.COMMIT, commitid)
meta = commit.get_child_value(0)
version = meta.lookup_value('version', GLib.VariantType.new('s'))
if version is None:
    fatal("Currently booted commit {0} does not have a version".format(commitid))
print(version.get_string())