Add script to automatically backport PR to release branch (#1097)

pyproject.toml

@@ -80,6 +80,7 @@ task-tags = ["Example", "todo", "TODO", "FIXME"]
 "manage.py" = ["INP"]
 "*/tests/*" = ["T20"]
 "boefjes/boefjes/plugins/*" = ["PTH"]
+"scripts/*.py" = ["INP001", "T201"]
 
 [tool.ruff.flake8-tidy-imports]
 [tool.ruff.flake8-tidy-imports.banned-api]

scripts/backport.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+
+import argparse
+import sys
+from pathlib import Path
+
+import yaml
+from git import Repo
+from gitdb.exc import BadName
+from github import Github
+
+
+def get_pr_num_from_message(message):
+    title = message.split("\n")[0]
+    if "(#" not in title:
+        return None
+
+    return int(title.split("(#")[-1].strip(")"))
+
+
+def get_commit_and_pr(repo, commit_or_pr):
+    # Make sure we have the latest version of the main branch to search for the
+    # commit
+    repo.heads["main"].checkout()
+    repo.remotes["origin"].pull()
+
+    try:
+        # If argument is an integer treat it as PR number, else commit ID
+        pr = int(commit_or_pr)
+    except ValueError:
+        try:
+            commit = repo.commit(commit_or_pr)
+            pr = get_pr_num_from_message(commit.message)
+        except BadName:
+            # Lookup commit ID
+            print(f"Can't find commit {commit_or_pr}")
+            sys.exit(1)
+    else:
+        for commit in repo.iter_commits("main"):
+            if get_pr_num_from_message(commit.message) == pr:
+                break
+        else:
+            print(f"Can't find PR {pr}")
+            sys.exit(1)
+
+    return commit, pr
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description="Backport PR to release branch. Will cherry pick the commit and create GitHub PR."
+    )
+    parser.add_argument("release", type=str, help="Release to backport to")
+    parser.add_argument("commit_or_pr", type=str, help="Commit ID or PR number to backport")
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    repo = Repo(".")
+    commit, pr = get_commit_and_pr(repo, args.commit_or_pr)
+
+    branch_name = f"backport-{pr}-{args.release}"
+
+    release_branch = f"release-{args.release}"
+
+    if branch_name in repo.heads:
+        print(f"Not creating branch {branch_name} because it already exists")
+        repo.heads[branch_name].checkout()
+    else:
+        # Checkout release branch
+        repo.heads[release_branch].checkout()
+
+        # Make sure we have the latest release of the release branch
+        repo.remotes["origin"].pull()
+
+        new_branch = repo.create_head(branch_name)
+        new_branch.checkout()
+
+        repo.git.cherry_pick(commit)
+
+    repo.remotes["origin"].push()
+
+    with (Path.home() / ".config" / "gh" / "hosts.yml").open() as f:
+        token = yaml.safe_load(f.read())["github.com"]["oauth_token"]
+
+    g = Github(token)
+
+    # Remote can be of the form https://github.com/user/repo.git or git@github.com:user/repo.git
+    github_repo = repo.remotes["origin"].url.replace("https://github.com/", "").replace("git@github.com:", "")
+    github_repo = github_repo.removesuffix(".git")
+
+    repo = g.get_repo(github_repo)
+
+    orig_title = commit.message.split("\n")[0]
+    title = orig_title.replace(f"#{pr}", args.release)
+    body = f"Backport of #{pr} to release {args.release}"
+
+    created_pr = repo.create_pull(title=title, body=body, head=branch_name, base=release_branch)
+
+    print("Successfully created PR:", created_pr.html_url)
+
+
+if __name__ == "__main__":
+    main()