Add milestones script

Adds a script to help with adding or removing Dawn milestones.

Bug: chromium:1432491
Change-Id: I0882503f4ceb7ba3454e13ec1669c053055ac975
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/133165
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Brian Sheedy <bsheedy@google.com>
Reviewed-by: Garrett Beaty <gbeaty@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>

infra/config/scripts/milestones.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+#
+# Copyright 2023 The Dawn Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Script for updating the active milestones for the Dawn project.
+
+This is largely based on the Chromium equivalent in
+chromium/src/infra/config/scripts/milestones.py.
+
+To activate a new branch, run the following from the root of the repo (where MMM
+is the milestone number and BBBB is the branch number):
+```
+infra/config/scripts/milestones.py activate --milestone MMM --branch BBBB
+infra/config/global/main.star
+```
+
+To deactivate a branch, run the following from the root of the repo (where MMM
+is the milestone number):
+```
+infra/config/scripts/milestones.py deactivate --milestone MMM
+infra/config/global/main.star
+```
+"""
+
+import argparse
+import json
+import os
+
+INFRA_CONFIG_GLOBAL_DIR = os.path.realpath(
+    os.path.join(os.path.dirname(__file__), '..', 'global'))
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description='Update the active milestones for the Dawn project')
+    parser.set_defaults(func=None)
+    parser.add_argument('--milestones-json',
+                        default=os.path.join(INFRA_CONFIG_GLOBAL_DIR,
+                                             'milestones.json'),
+                        help='Path to the milestones.json file to modify')
+
+    subparsers = parser.add_subparsers()
+
+    activate_parser = subparsers.add_parser(
+        'activate', help='Add an additional active milestone.')
+    activate_parser.set_defaults(func=cmd_activate)
+    activate_parser.add_argument(
+        '--milestone',
+        required=True,
+        type=int,
+        help='The milestone identifier/release channel number')
+    activate_parser.add_argument(
+        '--branch',
+        required=True,
+        help='The branch name, which should correspond to a ref in refs/heads')
+
+    deactivate_parser = subparsers.add_parser(
+        'deactivate', help='Remove an active milestone')
+    deactivate_parser.set_defaults(func=cmd_deactivate)
+    deactivate_parser.add_argument(
+        '--milestone',
+        required=True,
+        type=int,
+        help='The milestone identifier/release channel number')
+
+    args = parser.parse_args()
+    if not args.func:
+        parser.error('No sub-command specified')
+    return args
+
+
+def _sort_milestones(milestones):
+    # We have to manually sort here instead of relying on
+    # json.dump(..., sort_keys=True) later since we only want to sort the top
+    # level keys, not all keys.
+    milestones = {
+        str(k): milestones[str(k)]
+        for k in sorted([int(s) for s in milestones])
+    }
+    return milestones
+
+
+def add_milestone(milestones, milestone_num, branch):
+    if str(milestone_num) in milestones:
+        raise RuntimeError('Milestone %d already exists' % milestone_num)
+
+    milestones[str(milestone_num)] = {
+        'name': f'm{milestone_num}',
+        'chromium_project': f'chromium-m{milestone_num}',
+        'ref': f'refs/heads/{branch}',
+        'platforms': [
+            'linux',
+            'mac',
+            'win',
+        ],
+    }
+
+    return _sort_milestones(milestones)
+
+
+def remove_milestone(milestones, milestone_num):
+    if str(milestone_num) not in milestones:
+        raise RuntimeError('Milestone %d does not exist' % milestone_num)
+    del milestones[str(milestone_num)]
+    # Not strictly necessary, but returning a value keeps this consistent with
+    # add_milestone.
+    return milestones
+
+
+def cmd_activate(args):
+    with open(args.milestones_json) as infile:
+        milestones = json.load(infile)
+    milestones = add_milestone(milestones, args.milestone, args.branch)
+    with open(args.milestones_json, 'w') as outfile:
+        json.dump(milestones, outfile, indent=4)
+
+
+def cmd_deactivate(args):
+    with open(args.milestones_json) as infile:
+        milestones = json.load(infile)
+    milestones = remove_milestone(milestones, args.milestone)
+    with open(args.milestones_json, 'w') as outfile:
+        json.dump(milestones, outfile, indent=4)
+
+
+def main():
+    args = parse_args()
+    args.func(args)
+
+
+if __name__ == '__main__':
+    main()