Add script used to generate devstats repo groups

This isn't perfect, but it's probably better living here
than in a random gist I have laying around.

hack/generate-devstats-repo-sql.py

@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+
+# Copyright 2019 The Kubernetes 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.
+
+"""
+Output devstats repo_groups.sql based on subproject defintions in sigs.yaml
+
+This is likely missing a few repos because:
+    - some repos lack an owner (eg: kubernetes/kubernetes)
+    - it doesn't enumerate all repos from all kubernetes-owned orgs
+    - it ignores the fact that committees can own repos, only grouping by sig
+
+The sql generated is NOT intended to overwrite/replace the file that lives at
+github.com/cncf/devstats/scripts/kubernetes/repo_groups.sql, but instead aid a
+human in doing some manual updates to the file. Future improvements to this
+script could eliminate that part of the process, but it's where we are today.
+"""
+
+import argparse
+import ruamel.yaml as yaml
+import json
+import re
+import sys
+
+update_gha_repos_template = """
+update gha_repos set repo_group = 'SIG {}' where name in (
+{}
+);
+"""
+
+def repos_from_sig(sig):
+    """Returns a list of org/repos given a sig"""
+    repos = {}
+    subprojects = sig.get('subprojects', [])
+    if subprojects is None:
+        subprojects = []
+    for sp in subprojects:
+        for uri in sp['owners']:
+            owners_path = re.sub(r"https://raw.githubusercontent.com/(.*)/master/(.*)",r"\1/\2",uri)
+            path_parts = owners_path.split('/')
+            # org/repo is owned by sig if org/repo/OWNERS os in one of their subprojects
+            if path_parts[2] == 'OWNERS':
+                repo = '/'.join(path_parts[0:2])
+                repos[repo] = True
+    return sorted(repos.keys())
+
+def write_repo_groups_sql(sigs, fp):
+    for sig in sigs['sigs']:
+        repos = repos_from_sig(sig)
+        if len(repos):
+            fp.write(
+                update_gha_repos_template.format(
+                    sig['name'],
+                    ',\n'.join(['  \'{}\''.format(r) for r in repos])))
+
+def main(sigs_yaml, repo_groups_sql):
+    with open(sigs_yaml) as fp:
+        sigs = yaml.round_trip_load(fp)
+
+    if repo_groups_sql is not None:
+        with open(repo_groups_sql, 'w') as fp:
+            write_repo_groups_sql(sigs, fp)
+    else:
+        write_repo_groups_sql(sigs, sys.stdout)
+
+if __name__ == '__main__':
+    PARSER = argparse.ArgumentParser(
+        description='Do things with sigs.yaml')
+    PARSER.add_argument(
+        '--sigs-yaml',
+        default='./sigs.yaml',
+        help='Path to sigs.yaml')
+    PARSER.add_argument(
+        '--repo-groups-sql',
+        help='Path to output repo_groups.sql if provided')
+    ARGS = PARSER.parse_args()
+
+    main(ARGS.sigs_yaml, ARGS.repo_groups_sql)
+