ci: cut rc/<X.Y.0> off main every Friday at 3am Pacific (#43121)

* ci: cut rc/<X.Y.0> off main every Friday at 3am Pacific

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* ci: refuse to cut rc branch from a ref other than main

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* ci: move rc version check into .github/scripts/read_rc_version.py with tests

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* ci: fall back to tomli for the rc version script on Python 3.10

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* test: type the read_rc_version test helper

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

---------

Co-authored-by: yuneng <yuneng@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/scripts/read_rc_version.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+"""Print `version=X.Y.0` from [project].version in pyproject.toml for $GITHUB_OUTPUT.
+
+Usage
+-----
+    python3 read_rc_version.py [path/to/pyproject.toml] >> "$GITHUB_OUTPUT"
+
+Exit code 1 with a `::error::` line on stderr when the version is not an X.Y.0 release.
+"""
+
+from __future__ import annotations
+
+import pathlib
+import re
+import sys
+from typing import Final
+
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    import tomli as tomllib
+
+RELEASE_VERSION: Final = re.compile(r"[0-9]+\.[0-9]+\.0")
+
+
+def read_version(pyproject: pathlib.Path) -> str:
+    with pyproject.open("rb") as f:
+        return tomllib.load(f)["project"]["version"]
+
+
+def main(argv: list[str]) -> int:
+    pyproject: Final = pathlib.Path(argv[1]) if len(argv) > 1 else pathlib.Path("pyproject.toml")
+    version: Final = read_version(pyproject)
+    if RELEASE_VERSION.fullmatch(version) is None:
+        print(  # noqa: T201  # the ::error:: line to stderr is the workflow's failure signal
+            f"::error::pyproject.toml version {version} is not an X.Y.0 release version", file=sys.stderr
+        )
+        return 1
+    print(f"version={version}")  # noqa: T201  # stdout line is appended to $GITHUB_OUTPUT
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))

.github/workflows/create-rc-branch.yml

@@ -0,0 +1,66 @@
+name: Create RC Branch
+
+on:
+  schedule:
+    - cron: "0 3 * * 5"
+      timezone: "America/Los_Angeles"
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  create-rc-branch:
+    name: Create RC Branch
+    if: github.event_name != 'schedule' || github.repository == 'BerriAI/litellm'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Require main
+        env:
+          REF: ${{ github.ref }}
+        run: |
+          if [ "$REF" != "refs/heads/main" ]; then
+            echo "::error::rc branches are cut from refs/heads/main only, got $REF"
+            exit 1
+          fi
+
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        with:
+          persist-credentials: false
+
+      - name: Read release version
+        id: version
+        run: python3 .github/scripts/read_rc_version.py >> "$GITHUB_OUTPUT"
+
+      - name: Create rc branch
+        env:
+          VERSION: ${{ steps.version.outputs.version }}
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          script: |
+            const branchName = `rc/${process.env.VERSION}`;
+            const ref = `heads/${branchName}`;
+
+            const existing = await github.rest.git.getRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref,
+            }).catch((error) => {
+              if (error.status === 404) {
+                return null;
+              }
+              throw error;
+            });
+            if (existing !== null) {
+              core.setFailed(`Branch ${branchName} already exists at ${existing.data.object.sha}; leaving it untouched`);
+              return;
+            }
+
+            await github.rest.git.createRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `refs/${ref}`,
+              sha: context.sha,
+            });
+            core.info(`Created branch ${branchName} at ${context.sha}`);

tests/test_litellm/test_read_rc_version.py

@@ -0,0 +1,49 @@
+"""Tests for .github/scripts/read_rc_version.py."""
+
+import importlib.util
+import sys
+from pathlib import Path
+from typing import Final
+
+import pytest
+
+_REPO_ROOT: Final = Path(__file__).resolve().parents[2]
+_MODULE_PATH: Final = _REPO_ROOT / ".github" / "scripts" / "read_rc_version.py"
+_spec: Final = importlib.util.spec_from_file_location("read_rc_version", _MODULE_PATH)
+read_rc_version: Final = importlib.util.module_from_spec(_spec)
+sys.modules[_spec.name] = read_rc_version
+_spec.loader.exec_module(read_rc_version)
+
+
+def _run(tmp_path: Path, version: str, capsys: pytest.CaptureFixture[str]) -> tuple[int, str, str]:
+    pyproject: Final = tmp_path / "pyproject.toml"
+    pyproject.write_text(f'[project]\nname = "litellm"\nversion = "{version}"\n', encoding="utf-8")
+    code: Final = read_rc_version.main(["read_rc_version.py", str(pyproject)])
+    captured: Final = capsys.readouterr()
+    return code, captured.out, captured.err
+
+
+@pytest.mark.parametrize("version", ["1.104.0", "2.0.0", "10.250.0"])
+def test_an_x_y_0_version_is_printed_as_a_github_output_line(
+    tmp_path: Path, capsys: pytest.CaptureFixture[str], version: str
+) -> None:
+    code, out, err = _run(tmp_path, version, capsys)
+    assert (code, out, err) == (0, f"version={version}\n", "")
+
+
+@pytest.mark.parametrize("version", ["1.104.1", "1.104.0rc1", "1.104", "v1.104.0", "1.104.0.dev1"])
+def test_a_non_release_version_exits_1_without_printing_a_version(
+    tmp_path: Path, capsys: pytest.CaptureFixture[str], version: str
+) -> None:
+    code, out, err = _run(tmp_path, version, capsys)
+    assert code == 1
+    assert out == ""
+    assert err == f"::error::pyproject.toml version {version} is not an X.Y.0 release version\n"
+
+
+def test_the_repo_pyproject_is_read_when_no_path_is_given(
+    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+) -> None:
+    monkeypatch.chdir(_REPO_ROOT)
+    assert read_rc_version.main(["read_rc_version.py"]) == 0
+    assert capsys.readouterr().out == f"version={read_rc_version.read_version(_REPO_ROOT / 'pyproject.toml')}\n"