Use manual trigger to prepare release PRs (#8150)

Co-authored-by: Ran Benita <ran@unusedvar.com>

.github/workflows/prepare-release-pr.yml

@@ -0,0 +1,42 @@
+name: prepare release pr
+
+on:
+  workflow_dispatch:
+    inputs:
+      branch:
+        description: 'Branch to base the release from'
+        required: true
+        default: ''
+      major:
+        description: 'Major release? (yes/no)'
+        required: true
+        default: 'no'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: "3.8"
+
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install --upgrade setuptools tox
+
+    - name: Prepare release PR (minor/patch release)
+      if: github.event.inputs.branch.major == 'no'
+      run: |
+        tox -e prepare-release-pr -- ${{ github.event.inputs.branch }} ${{ secrets.chatops }}
+
+    - name: Prepare release PR (major release)
+      if: github.event.inputs.branch.major == 'yes'
+      run: |
+        tox -e prepare-release-pr -- ${{ github.event.inputs.branch }} ${{ secrets.chatops }} --major

scripts/prepare-release-pr.py

@@ -0,0 +1,151 @@
+"""
+This script is part of the pytest release process which is triggered manually in the Actions
+tab of the repository.
+
+The user will need to enter the base branch to start the release from (for example
+``6.1.x`` or ``master``) and if it should be a major release.
+
+The appropriate version will be obtained based on the given branch automatically.
+
+After that, it will create a release using the `release` tox environment, and push a new PR.
+
+**Secret**: currently the secret is defined in the @pytestbot account,
+which the core maintainers have access to. There we created a new secret named `chatops`
+with write access to the repository.
+"""
+import argparse
+import re
+from pathlib import Path
+from subprocess import check_call
+from subprocess import check_output
+from subprocess import run
+
+from colorama import Fore
+from colorama import init
+from github3.repos import Repository
+
+
+class InvalidFeatureRelease(Exception):
+    pass
+
+
+SLUG = "pytest-dev/pytest"
+
+PR_BODY = """\
+Created automatically from manual trigger.
+
+Once all builds pass and it has been **approved** by one or more maintainers, the build
+can be released by pushing a tag `{version}` to this repository.
+"""
+
+
+def login(token: str) -> Repository:
+    import github3
+
+    github = github3.login(token=token)
+    owner, repo = SLUG.split("/")
+    return github.repository(owner, repo)
+
+
+def prepare_release_pr(base_branch: str, is_major: bool, token: str) -> None:
+    print()
+    print(f"Processing release for branch {Fore.CYAN}{base_branch}")
+
+    check_call(["git", "checkout", f"origin/{base_branch}"])
+
+    try:
+        version = find_next_version(base_branch, is_major)
+    except InvalidFeatureRelease as e:
+        print(f"{Fore.RED}{e}")
+        raise SystemExit(1)
+
+    print(f"Version: {Fore.CYAN}{version}")
+
+    release_branch = f"release-{version}"
+
+    run(
+        ["git", "config", "user.name", "pytest bot"],
+        text=True,
+        check=True,
+        capture_output=True,
+    )
+    run(
+        ["git", "config", "user.email", "pytestbot@gmail.com"],
+        text=True,
+        check=True,
+        capture_output=True,
+    )
+
+    run(
+        ["git", "checkout", "-b", release_branch, f"origin/{base_branch}"],
+        text=True,
+        check=True,
+        capture_output=True,
+    )
+
+    print(f"Branch {Fore.CYAN}{release_branch}{Fore.RESET} created.")
+
+    # important to use tox here because we have changed branches, so dependencies
+    # might have changed as well
+    cmdline = ["tox", "-e", "release", "--", version, "--skip-check-links"]
+    print("Running", " ".join(cmdline))
+    run(
+        cmdline, text=True, check=True, capture_output=True,
+    )
+
+    oauth_url = f"https://{token}:x-oauth-basic@github.com/{SLUG}.git"
+    run(
+        ["git", "push", oauth_url, f"HEAD:{release_branch}", "--force"],
+        text=True,
+        check=True,
+        capture_output=True,
+    )
+    print(f"Branch {Fore.CYAN}{release_branch}{Fore.RESET} pushed.")
+
+    body = PR_BODY.format(version=version)
+    repo = login(token)
+    pr = repo.create_pull(
+        f"Prepare release {version}", base=base_branch, head=release_branch, body=body,
+    )
+    print(f"Pull request {Fore.CYAN}{pr.url}{Fore.RESET} created.")
+
+
+def find_next_version(base_branch: str, is_major: bool) -> str:
+    output = check_output(["git", "tag"], encoding="UTF-8")
+    valid_versions = []
+    for v in output.splitlines():
+        m = re.match(r"\d.\d.\d+$", v.strip())
+        if m:
+            valid_versions.append(tuple(int(x) for x in v.split(".")))
+
+    valid_versions.sort()
+    last_version = valid_versions[-1]
+
+    changelog = Path("changelog")
+
+    features = list(changelog.glob("*.feature.rst"))
+    breaking = list(changelog.glob("*.breaking.rst"))
+    is_feature_release = features or breaking
+
+    if is_major:
+        return f"{last_version[0]+1}.0.0"
+    elif is_feature_release:
+        return f"{last_version[0]}.{last_version[1] + 1}.0"
+    else:
+        return f"{last_version[0]}.{last_version[1]}.{last_version[2] + 1}"
+
+
+def main() -> None:
+    init(autoreset=True)
+    parser = argparse.ArgumentParser()
+    parser.add_argument("base_branch")
+    parser.add_argument("token")
+    parser.add_argument("--major", action="store_true", default=False)
+    options = parser.parse_args()
+    prepare_release_pr(
+        base_branch=options.base_branch, is_major=options.major, token=options.token
+    )
+
+
+if __name__ == "__main__":
+    main()

tox.ini

@@ -157,6 +157,13 @@ passenv = {[testenv:release]passenv}
 deps = {[testenv:release]deps}
 commands = python scripts/release-on-comment.py {posargs}
 
+[testenv:prepare-release-pr]
+decription = prepare a release PR from a manual trigger in GitHub actions
+usedevelop = {[testenv:release]usedevelop}
+passenv = {[testenv:release]passenv}
+deps = {[testenv:release]deps}
+commands = python scripts/prepare-release-pr.py {posargs}
+
 [testenv:publish-gh-release-notes]
 description = create GitHub release after deployment
 basepython = python3