do-release-tags

#!/usr/bin/env python
#
# Ensure that the specified refs match a releases.yml file
# that is stored in git.
#
# Copyright 2016 Colin Walters <walters@verbum.org>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 2 of the License, or (at your option) any later version.
# 
#  This library 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
#  Lesser General Public License for more details.
# 
#  You should have received a copy of the GNU Lesser General Public
#  License along with this library. If not, see <http://www.gnu.org/licenses/>.

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

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

parser = argparse.ArgumentParser(prog=sys.argv[0])
parser.add_argument("--autocreate", help="Create refs that don't already exist",
		    action='store_true')
parser.add_argument("--ignore-no-previous-promotion", help="Releases file",
		    action='store_true')
parser.add_argument("--repo", help="Repo path",
                    action='store', required=True)
parser.add_argument("--releases", help="Releases file",
		    action='store', required=True)

args = parser.parse_args()

r = OSTree.Repo.new(Gio.File.new_for_path(args.repo))
r.open(None)

releasedata = yaml.load(open(args.releases))
baseref = releasedata['baseref']
changed = False
for (name,newcommit) in releasedata['releases'].iteritems():
    ref = baseref + name
    [_, current] = r.resolve_rev(ref, True)
    if current is None:
        if args.autocreate:
            print("Creating new ref {}.".format(ref))
            newparent = None
        else:
            fatal("error: Ref {} does not currently exist".format(ref))
    else:
        _,currentcommitdata,_ = r.load_commit(current)
        currentcommitmeta = currentcommitdata.get_child_value(0)
        currentpromotedv = currentcommitmeta.lookup_value("promotion-of", GLib.VariantType.new("s"))
        if currentpromotedv is None:
            msg = "Missing promotion-of metadata key in {}".format(current)
            if args.ignore_no_previous_promotion:
                print("warning: " + msg)
                currentpromoted = '(missing)'
                newparent = None
            else:
                fatal(msg)
        else:
            currentpromoted = currentpromotedv.get_string()
            newparent = current
            if currentpromoted == newcommit:
                print("No changes in {} = {}, promoted from {}".format(ref, current, currentpromoted))
                continue
        print("Previously: {} = {}, promoted from {}".format(ref, current, currentpromoted))
    _,newcommitdata,_ = r.load_commit(newcommit)
    _,newcommitroot,_ = r.read_commit(newcommit, None)
    newcommitmeta = newcommitdata.get_child_value(0)
    versionv = newcommitmeta.lookup_value("version", GLib.VariantType.new("s"))
    if versionv:
        version = versionv.get_string()

    promotedmetadict = GLib.VariantDict.new(newcommitmeta)
    promotedmetadict.insert_value("promotion-of", GLib.Variant.new_string(newcommit))
    body = 'PromotionOf: {}'.format(newcommit)

    mtree = OSTree.MutableTree.new()
    _,promotedcommit = r.write_commit(newparent, '', body, promotedmetadict.end(), newcommitroot, None)
    r.set_ref_immediate(None, ref, promotedcommit)
    if version:
        print "Promoted commit {} (version {}) => {}".format(newcommit, version, promotedcommit)
    changed = True
if not changed:
    print("Processed {}: No changes".format(args.releases))