[PATCH 1/3] Add export project as mbox management command

[Stephen Finucane]

On Mon, 2019-07-15 at 16:50 +0200, Mete Polat wrote:
> Introduces a new management command which can export all patches in a
> project as one mbox file. Export of multiple projects is supported.
> Additionaly allows to compress the output.

This looks good. Just two small comments below.

> Signed-off-by: Mete Polat <metepolat2000 at gmail.com>
> ---
> Also supports python2 with the force_bytes() function.
> 
>  .../management/commands/exportproject.py      | 71 +++++++++++++++++++
>  1 file changed, 71 insertions(+)
>  create mode 100644 patchwork/management/commands/exportproject.py
> 
> diff --git a/patchwork/management/commands/exportproject.py b/patchwork/management/commands/exportproject.py
> new file mode 100644
> index 0000000..7e18234
> --- /dev/null
> +++ b/patchwork/management/commands/exportproject.py
> @@ -0,0 +1,71 @@
> +# Patchwork - automated patch tracking system
> +# Copyright (C) 2019, Bayerische Motoren Werke Aktiengesellschaft (BMW AG) 
> +#
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +
> +import os
> +import tarfile
> +from uuid import uuid4
> +
> +from django.core.management import BaseCommand, CommandError
> +from django.utils.encoding import force_bytes
> +
> +from patchwork.models import Project, Patch
> +from patchwork.views.utils import patch_to_mbox
> +
> +
> +class Command(BaseCommand):
> +    help = 'Export patchwork projects as mbox files and optionally compress '
> +    'the result.'
> +
> +    def add_arguments(self, parser):
> +        parser.add_argument(
> +            '-c', '--compress', action='store_true',
> +            help='Bundle and compress projects.'
> +        )
> +        parser.add_argument(
> +            '-l', '--level', action='store', type=int, default=9,
> +            help='Set a compression level between 0 and 9 (default). 0 is no '
> +                 'compression. '
> +        )

Do we need this knob? It seems defaulting to 9 if the '-c' flag is
provided would be fine for 90% of users?

> +        parser.add_argument(
> +            'project_linkname', nargs='*',
> +            help='Project linknames. Export all projects if none specified.'
> +        )
> +
> +    def handle(self, *args, **options):
> +        if options['project_linkname']:
> +            projects = []
> +            for p_linkname in options['project_linkname']:
> +                try:
> +                    projects.append(Project.objects.get(linkname=p_linkname))
> +                except Project.DoesNotExist:
> +                    raise CommandError('%s: Project not found' % p_linkname)
> +        else:
> +            projects = Project.objects.all()
> +
> +        compress = options['compress']
> +        level = options['level']
> +
> +        tar = None
> +        if compress:
> +            name = projects[0].linkname if len(projects) == 1 else 'patchwork'

Any reason not to use 'projects[0].linkname' if len(projects) == 1 too?

> +            name += '.tar' if level == 0 else '.tar.gz'
> +            tar = tarfile.open(name, 'w:gz', compresslevel=level)
> +
> +        try:
> +            for project in projects:
> +                name = project.linkname + '.mbox'
> +                tmp_name = '%s_%s' % (project.linkname, uuid4().hex)
> +                with open(tmp_name, 'wb') as mbox:
> +                    for patch in Patch.objects.filter(patch_project=project):
> +                        mbox.write(force_bytes(patch_to_mbox(patch) + '\n'))
> +                    mbox.close()
> +                    if compress:
> +                        tar.add(tmp_name, arcname=name)
> +                        os.remove(tmp_name)
> +                    else:
> +                        os.rename(tmp_name, name)
> +        finally:
> +            if tar is not None:
> +                tar.close()