#!/usr/bin/env python3
"""
Create or update a GitHub Release from CHANGELOG.md when a tag is pushed.
Trigger: tags like vX.Y.Z (see .github/workflows/release.yml).
Behavior:
- Extracts the CHANGELOG section starting with '## X.Y.Z' (optionally followed by ' - <date>')
- Creates the GitHub Release if it doesn't exist
- Updates the Release body if it already exists (idempotent)
No external deps (stdlib only).
"""
from __future__ import annotations
import json
import os
import re
import urllib.error
import urllib.request
from pathlib import Path
def _req(method: str, url: str, token: str, body: dict | None = None) -> tuple[int, str]:
data = None if body is None else json.dumps(body).encode("utf-8")
req = urllib.request.Request(url, data=data, method=method)
req.add_header("Authorization", f"token {token}")
req.add_header("Accept", "application/vnd.github+json")
req.add_header("X-GitHub-Api-Version", "2022-11-28")
if data is not None:
req.add_header("Content-Type", "application/json")
try:
with urllib.request.urlopen(req) as resp: # nosec B310 (GitHub endpoint)
return resp.status, resp.read().decode("utf-8")
except urllib.error.HTTPError as e:
return e.code, e.read().decode("utf-8")
def _extract_section(changelog: str, version: str) -> str:
"""
Extract section starting with '## {version}' (optionally followed by date),
up to next '## ' heading.
"""
lines = changelog.splitlines()
start: int | None = None
header_re = re.compile(rf"^##\s+{re.escape(version)}(\s+-.*)?$")
for i, ln in enumerate(lines):
if header_re.match(ln.strip()):
start = i
break
if start is None:
raise RuntimeError(f"CHANGELOG section for version {version} not found")
end = len(lines)
for j in range(start + 1, len(lines)):
if lines[j].startswith("## "):
end = j
break
return "\n".join(lines[start:end]).strip() + "\n"
def main() -> int:
token = os.environ.get("GITHUB_TOKEN")
repo = os.environ.get("GITHUB_REPOSITORY") # owner/name
tag = os.environ.get("GITHUB_REF_NAME") # vX.Y.Z
if not token or not repo or not tag:
raise SystemExit("Missing GITHUB_TOKEN, GITHUB_REPOSITORY, or GITHUB_REF_NAME")
if not tag.startswith("v"):
print(f"Tag {tag} does not start with v; skipping")
return 0
version = tag[1:]
body = _extract_section(Path("CHANGELOG.md").read_text(encoding="utf-8"), version)
api = f"https://api.github.com/repos/{repo}"
payload = {"tag_name": tag, "name": tag, "body": body, "draft": False, "prerelease": False}
st, txt = _req("GET", f"{api}/releases/tags/{tag}", token)
if st == 200:
rel = json.loads(txt)
rel_id = rel.get("id")
if not rel_id:
raise RuntimeError("Release exists but id missing")
st2, txt2 = _req("PATCH", f"{api}/releases/{rel_id}", token, payload)
if st2 not in (200, 201):
raise RuntimeError(f"Failed to update release: HTTP {st2} {txt2}")
print(f"OK: updated release for {tag}")
return 0
if st != 404:
raise RuntimeError(f"Failed to check release: HTTP {st} {txt}")
st3, txt3 = _req("POST", f"{api}/releases", token, payload)
if st3 not in (200, 201):
raise RuntimeError(f"Failed to create release: HTTP {st3} {txt3}")
print(f"OK: created release for {tag}")
return 0
if __name__ == "__main__":
raise SystemExit(main())
