Automated backporting machinery (#12029)

* Add automated cherry-pick machinery

* Added script for backporting machinery

* Implement dry-run mode

* Comment old methods

* Fix python2

* Add ya.make for sandbox tasks

* Remove old stuff

utils/github/backport.py

@@ -0,0 +1,104 @@
+# -*- coding: utf-8 -*-
+
+from query import Query as RemoteRepo
+from local import BareRepository as LocalRepo
+import cherrypick
+
+import argparse
+import logging
+import re
+import sys
+
+
+class Backport:
+    def __init__(self, token, owner, name, team):
+        '''
+        `refs` is a list of (ref_path, base_commit) sorted by ancestry starting from the least recent ref.
+        '''
+        self._gh = RemoteRepo(token, owner=owner, name=name, team=team, max_page_size=30)
+        self.default_branch_name = self._gh.default_branch
+
+    def getPullRequests(self, from_commit):
+        return self._gh.get_pull_requests(from_commit)
+
+
+def run(token, repo_bare, til, number, run_cherrypick):
+    bp = Backport(token, 'ClickHouse', 'ClickHouse', 'core')
+    repo = LocalRepo(repo_bare, bp.default_branch_name)
+
+    branches = repo.get_release_branches()[-number:]  # [(branch_name, base_commit)]
+
+    if not branches:
+        logging.info('No release branches found!')
+        return
+
+    for branch in branches:
+        logging.info('Found release branch: %s', branch[0])
+
+    if not til:
+        til = branches[0][1]
+    prs = bp.getPullRequests(til)
+
+    backport_map = {}
+
+    RE_MUST_BACKPORT = re.compile(r'^v(\d+\.\d+)-must-backport$')
+    RE_NO_BACKPORT = re.compile(r'^v(\d+\.\d+)-no-backport$')
+
+    # pull-requests are sorted by ancestry from the least recent.
+    for pr in prs:
+        while repo.comparator(branches[-1][1]) >= repo.comparator(pr['mergeCommit']['oid']):
+            branches.pop()
+
+        assert len(branches)
+
+        branch_set = set([branch[0] for branch in branches])
+
+        # First pass. Find all must-backports
+        for label in pr['labels']['nodes']:
+            if label['name'].startswith('pr-') and label['color'] == 'ff0000':
+                backport_map[pr['number']] = branch_set.copy()
+                continue
+            m = RE_MUST_BACKPORT.match(label['name'])
+            if m:
+                if pr['number'] not in backport_map:
+                    backport_map[pr['number']] = set()
+                backport_map[pr['number']].add(m.group(1))
+
+        # Second pass. Find all no-backports
+        for label in pr['labels']['nodes']:
+            if label['name'] == 'pr-no-backport' and pr['number'] in backport_map:
+                del backport_map[pr['number']]
+                break
+            m = RE_NO_BACKPORT.match(label['name'])
+            if m and pr['number'] in backport_map and m.group(1) in backport_map[pr['number']]:
+                backport_map[pr['number']].remove(m.group(1))
+
+    for pr, branches in backport_map.items():
+        logging.info('PR #%s needs to be backported to:', pr)
+        for branch in branches:
+            logging.info('\t%s %s', branch, run_cherrypick(token, pr, branch))
+
+    # print API costs
+    logging.info('\nGitHub API total costs per query:')
+    for name, value in bp._gh.api_costs.items():
+        logging.info('%s : %s', name, value)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--token',     type=str, required=True, help='token for Github access')
+    parser.add_argument('--repo-bare', type=str, required=True, help='path to bare repository', metavar='PATH')
+    parser.add_argument('--repo-full', type=str, required=True, help='path to full repository', metavar='PATH')
+    parser.add_argument('--til',       type=str,                help='check PRs from HEAD til this commit', metavar='COMMIT')
+    parser.add_argument('-n',          type=int, dest='number', help='number of last release branches to consider')
+    parser.add_argument('--dry-run',   action='store_true',     help='do not create or merge any PRs', default=False)
+    parser.add_argument('--verbose', '-v', action='store_true', help='more verbose output', default=False)
+    args = parser.parse_args()
+
+    if args.verbose:
+        logging.basicConfig(format='%(message)s', stream=sys.stdout, level=logging.DEBUG)
+    else:
+        logging.basicConfig(format='%(message)s', stream=sys.stdout, level=logging.INFO)
+
+    cherrypick_run = lambda token, pr, branch: cherrypick.run(token, pr, branch, args.repo_full, args.dry_run)
+    run(args.token, args.repo_bare, args.til, args.number, cherrypick_run)