Add pyl files to generate the tests config.

The config is only added for the bot luci.webrtc.ci:"Linux64 Release" as a proof of concept.

Bug: webrtc:13899
Change-Id: I5ac37da5f63ca4b1c346dffe43e635b2c55e0c01
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/257160
Reviewed-by: Christoffer Jansson <jansson@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Cr-Commit-Position: refs/heads/main@{#36417}

infra/specs/generate_buildbot_json.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env vpython3
+# Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+"""Script to generate the test spec JSON files and the mixins.pyl file from the
+ADDITIONAL_MIXINS dictonary. Calls Chromium's generate_buildbot_json.
+"""
+
+import json
+import os
+import sys
+
+_SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+_SRC_DIR = os.path.dirname(os.path.dirname(_SCRIPT_DIR))
+sys.path.insert(0, _SRC_DIR)
+sys.path.insert(0, os.path.join(_SRC_DIR, 'testing', 'buildbot'))
+
+from testing.buildbot import generate_buildbot_json
+
+# Add custom mixins here.
+ADDITIONAL_MIXINS = {
+    'result_adapter': {
+        'resultdb': {
+            'result_format': 'json'
+        },
+    },
+}
+MIXIN_FILE_NAME = os.path.join(_SCRIPT_DIR, 'mixins.pyl')
+MIXINS_PYL_TEMPLATE = """\
+# GENERATED FILE - DO NOT EDIT.
+# Generated by {script_name} using data from
+# {data_source}
+#
+# Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+{mixin_data}
+"""
+
+
+def main():
+  chromium_args = generate_buildbot_json.BBJSONGenerator.parse_args(argv=None)
+  chromium_generator = generate_buildbot_json.BBJSONGenerator(chromium_args)
+  chromium_generator.load_configuration_files()
+
+  override_args = ['--pyl-files-dir', _SCRIPT_DIR]
+  webrtc_args = generate_buildbot_json.BBJSONGenerator.parse_args(override_args)
+  webrtc_generator = generate_buildbot_json.BBJSONGenerator(webrtc_args)
+  webrtc_generator.load_configuration_files()
+  webrtc_generator.resolve_configuration_files()
+
+  seen_mixins = set()
+  for waterfall in webrtc_generator.waterfalls:
+    seen_mixins = seen_mixins.union(waterfall.get('mixins', set()))
+    for bot_name, tester in waterfall['machines'].items():
+      del bot_name
+      seen_mixins = seen_mixins.union(tester.get('mixins', set()))
+  for suite in webrtc_generator.test_suites.values():
+    for test in suite.values():
+      seen_mixins = seen_mixins.union(test.get('mixins', set()))
+
+  found_mixins = ADDITIONAL_MIXINS.copy()
+  for mixin in seen_mixins:
+    if mixin not in found_mixins:
+      found_mixins[mixin] = chromium_generator.mixins[mixin]
+
+  format_data = {
+      'script_name': os.path.basename(__file__),
+      'data_source': 'waterfall.pyl and Chromium\'s mixins.pyl',
+      'mixin_data': json.dumps(dict(sorted(found_mixins.items())), indent=2),
+  }
+  with open(MIXIN_FILE_NAME, 'w') as f:
+    f.write(MIXINS_PYL_TEMPLATE.format(**format_data))
+    f.close()
+
+  return webrtc_generator.main()
+
+
+if __name__ == '__main__':  # pragma: no cover
+  sys.exit(main())