image-diff

#!/usr/bin/python3

# This file is part of Cockpit.
#
# Copyright (C) 2020 Red Hat, Inc.
#
# Cockpit 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 2.1 of the License, or
# (at your option) any later version.
#
# Cockpit 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 Cockpit; If not, see <http://www.gnu.org/licenses/>.

import argparse

from machine import testvm


def get_packages(machine):
    # List all packages, irrespective of package manager (rpm or dpkg or pacman).
    # If both are missing, then the command will fail.
    #
    # We'd ideally like to get source packages everywhere, but it's a
    # bit more difficult on RPM. (TODO)
    pkgcmd = """if type dpkg-query > /dev/null 2>&1; then
                    dpkg-query -W 2>/dev/null;
                elif type rpm > /dev/null 2>&1; then
                    rpm -qa --qf '%{NAME}\t%{EVR}\n' 2>/dev/null;
                else pacman -Q | sed 's/ /\t/' 2>/dev/null; fi"""

    output = machine.execute(pkgcmd).strip()
    return dict(line.split('\t') for line in output.splitlines())


parser = argparse.ArgumentParser(description='Compare package versions on VM images')
parser.add_argument('old', help='the "old" image to compare')
parser.add_argument('new', help='the "new" image to compare')
args = parser.parse_args()

# boot the machines in parallel
old_vm = testvm.VirtMachine(image=args.old)
new_vm = testvm.VirtMachine(image=args.new)

old_vm.start()
new_vm.start()

old_vm.wait_boot()
new_vm.wait_boot()

old_pkgs = get_packages(old_vm)
new_pkgs = get_packages(new_vm)

old_vm.kill()
new_vm.kill()

print('Removed:')
for name in sorted(set(old_pkgs) - set(new_pkgs)):
    print(f'  {name} ({old_pkgs[name]})')
print()

print('Added:')
for name in sorted(set(new_pkgs) - set(old_pkgs)):
    print(f'  {name} ({new_pkgs[name]})')
print()

print('Changed:')
for name in sorted(set.intersection(set(new_pkgs), set(old_pkgs))):
    if new_pkgs[name] != old_pkgs[name]:
        print(f'  {name} ({old_pkgs[name]} -> {new_pkgs[name]})')
print()