gen_pr_req.py

"""
This is a utility hard-coded to Indra at the moment, but we should
move all of these constants into env vars so it can run for any build.
"""
from github import Github, Repository
import os

TOKEN = 'GITHUB_TOKEN'
REPO = 'PR_REPO'

INDRA_REPO = 'IndraABM'

token = os.getenv(TOKEN, None)

BASE_BRANCH = 'master'

HEAD_BRANCH = 'staging'

ORGANIZATION = 'TandonDevOps'

repo_name = os.getenv(REPO, INDRA_REPO)

"""
Since I (Abhinav) am using my own github account, the PR's are authored by me.
Due to this, I cannot add myself as a reviewer automatically.
Solution: Create a GitHub app/bot to create the PR.
"""
REV_FILE = 'rev_file'

rev_file = os.getenv(REV_FILE, 'db/reviewers.txt')

DEF_REVIEWERS = ['Denisfench', 'gcallah', 'NathanConroy']


def get_reviewers():
    reviewers = []
    try:
        with open(rev_file, 'r') as f:
            for line in f:
                reviewers.append(line.strip())
        return reviewers
    except FileNotFoundError:
        return DEF_REVIEWERS


def pr_already_exists(repo: Repository.Repository):
    pull_requests = repo.get_pulls(base=BASE_BRANCH, head=HEAD_BRANCH)
    if pull_requests.totalCount != 0:
        return True, pull_requests
    else:
        return False, None


def generate_pr():
    if not token:
        raise EnvironmentError(
            "Could not find github token. It is required to make an API "
            "call to create a PR. "
            "Please set it in your environment and re-start the build.")

    hub = Github(token)
    org = hub.get_organization(login=ORGANIZATION)
    repo = org.get_repo(name=repo_name)
    # Do not try to create a new PR if there is a PR out already.
    pr_exists, pull_requests = pr_already_exists(repo)
    if not pr_exists:
        head_branch = repo.get_branch(HEAD_BRANCH)
        base_branch = repo.get_branch(BASE_BRANCH)
        head_commit = head_branch.commit
        body = head_commit.commit.message
        title = 'Auto PR due to push to staging'
        pr = repo.create_pull(base=base_branch.name, head=head_branch.name,
                              body=body,
                              maintainer_can_modify=True, title=title,)

        pr.create_review_request(reviewers=get_reviewers(),
                                 team_reviewers=[])
        print(f'Created PR: {pr.html_url}')
    else:
        print('PR already exists. The push should have updated the PR.')
        for pr in pull_requests:
            print(pr.html_url)


if __name__ == "__main__":
    generate_pr()