Renaming main git branches from debian/master to debian/latest

[Amin Bandali <bandali@canonical.com>]

Hi folks,

Jeremy (Cc'd) and I propose to rename the main git development branch
for Debian GNOME team from 'debian/master' to 'debian/latest', and
similarly from 'ubuntu/master' to 'ubuntu/latest' where they exist.

Rationale
---------

- This aligns with the 2020 update to DEP-14.

- debian/latest would also parallel upstream/latest, which we use for
  our git-buildpackage workflow.

- This follows the industry-wide efforts towards deprecation of the
  term 'master' where possible.

Implementation details
----------------------

We believe it would be best if we make this change across all of our
repositories under the gnome-team group on Salsa, on a single day.

We propose to do this on Monday, 4 September 2023.

Once the change is carried out, you'd need to manually checkout the
debian/latest branch or just do a new 'gbp clone' to continue working
on gnome-team packages.

GitHub added a feature to simplify renaming branches, but GitLab
doesn't have this yet.  So, to automate this, we can use sed, git
itself, and the glab CLI tool by GitLab to make the following changes:

1. Change debian-branch in debian/gbp.conf from 'debian/master' to
   'debian/latest'.  This will cause many gbp commands to fail until
   the user switches to the debian/latest branch, so it's a helpful
   hint.

2. Push that change to both debian/master and debian/latest.

3. Update each repo's settings on Salsa to use debian/latest as the
   default branch.

4. Update each repo's settings on Salsa to "protect" debian/master to
   prevent any future pushes to the branch, effectively archiving it.

5. If ubuntu/master exists, follow similar steps as 1, 2, and 4.

6. Update the gnome-team group settings on Salsa to use debian/latest
   as the default branch for new projects (repos) going forward.

I have written a small script, git-debian-latest.sh, to carry out
steps 1 through 5.  You can find it attached to this message.

I welcome and appreciate your feedback/suggestions, and I would be
happy to try and address any questions or concerns you may have.

Thanks,
-a


References
----------

https://dep-team.pages.debian.net/deps/dep14/
https://github.com/github/renaming
https://inclusivenaming.org
https://gitlab.com/gitlab-org/cli

#!/bin/sh

# Copyright (C) 2023 Canonical Ltd.
#
# Author: Amin Bandali <bandali@ubuntu.com>
# This file:
#  https://people.ubuntu.com/~bandali/gnome-team/git-debian-latest.sh
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3, as
# published by the Free Software Foundation.
#
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

set -ux

# glab repo clone -g gnome-team --paginate

master_to_latest()
{
    sed -i "/debian-branch/s|$1/master|$1/latest|" debian/gbp.conf
    git add debian/gbp.conf
    git commit -m"Change debian-branch from $1/master to $1/latest"
    git push origin "$1/master"
    git branch -m "$1/latest"
    git push -u origin "$1/latest"
}

for dir in ./*/
do
    (
        cd $dir
        if [ -d .git ] && [ "$(git branch --show-current)" = "debian/master" ]
        then
            # debian/master -> debian/latest
            master_to_latest debian
            if git show-ref -q ubuntu/master
            then
                # ubuntu/master -> ubuntu/latest
                git branch ubuntu/master origin/ubuntu/master
                git checkout ubuntu/master
                master_to_latest ubuntu
            fi

            # make debian/latest the default branch
            glab api -XPUT /projects/:id -F 'default_branch=debian/latest'

            # prevent pushes and merges into debian/master
            glab api -XPOST /projects/:id/protected_branches \
                 -F 'name=debian/master' \
                 -F 'push_access_level=0' \
                 -F 'merge_access_level=0'
            if git show-ref -q ubuntu/master
            then
                # prevent pushes and merges into ubuntu/master
                glab api -XPOST /projects/:id/protected_branches \
                     -F 'name=ubuntu/master' \
                     -F 'push_access_level=0' \
                     -F 'merge_access_level=0'
            fi
        fi
    )
done