TeamCity Python build step to query GitHub GraphQL endpoint

query_github_graphql.py

import json
import requests
import subprocess


def query_github_graphql(url: str, api_token: str, owner: str, service: str, pull_request: int):
    headers = {'Authorization': 'bearer {}'.format(api_token), 'Content-Type': 'application/json'}
    payload = {'query': '{repository(owner:\"%s\", name: \"%s\"){pullRequest(number: %d){headRefName,baseRefName}}}' % (owner, service, pull_request)}
    response = requests.post(url=url, json=payload, headers=headers)
    print(response.text)

    response_dict = json.loads(response.text)

    target_branch = response_dict['data']['repository']['pullRequest']['baseRefName']
    pull_request_branch = response_dict['data']['repository']['pullRequest']['headRefName']

    subprocess.call(['echo', '##teamcity[setParameter name=\'targetBranch\' value=\'%s\']' % target_branch])
    subprocess.call(['echo', '##teamcity[setParameter name=\'pullRequestBranch\' value=\'%s\']' % pull_request_branch])


if '__main__' == __name__:
    query_github_graphql('%endpoint_url%', '%token%', '%owner%', '%repo%', %pull_request_number%)