website_deploy_hook.py

#!/usr/bin/env python3


from subprocess import check_call, CalledProcessError, STDOUT
import os
import json
import io
import sys

APP_DIR = ""
DEPLOYMENT_DIR = ""
JEKYLL_COMMAND = "jekyll"
os.environ['HOME'] = ""

EVENT_TYPE = 'event'

aliases = {
    EVENT_TYPE: ('X-GitHub-Event', 'X_GITHUB_EVENT', 'HTTP_X_GITHUB_EVENT')
}


class Event:

    def __init__(self, url, prerelease, draft, tag_name, **kwargs):

        self.url = url
        self.is_release = not prerelease and not draft
        self.tag_name = tag_name

    def checkout(self):
        check_call(["git", "fetch", "--all"], stdout=sys.stdout, stderr=STDOUT)
        check_call(["git", "checkout", "tags/" + self.tag_name], stdout=sys.stdout, stderr=STDOUT)

    def build(self, target=None):
        check_call([JEKYLL_COMMAND, 'build'] + (['--destination', target] if target is not None else []), stdout=sys.stdout, stderr=STDOUT)


def get_header(name):
    header_aliases = aliases[name]
    for alias in header_aliases:
        if alias in os.environ:
            return os.environ[alias]
    else:
        raise KeyError('For key {}'.format(name))


def update_site(event):
    os.chdir(APP_DIR)

    try:
        event.checkout()
    except CalledProcessError as e:
        print("Exception during fetch/checkout, error code: {}".format(e.returncode))
        return

    try:
        event.build(target=DEPLOYMENT_DIR)
    except CalledProcessError as e:
        print("Exception during jekyll build, error code: {}".format(e.returncode))
        return

    print('Successfully deployed tag {} to {}'.format(event.tag_name, DEPLOYMENT_DIR))


def handle(payload):
    event = Event(**payload['release'])

    if event.is_release:
        update_site(event)
    else:
        print('No update. (prerelease/draft)')


def receive():

    event_type = get_header(EVENT_TYPE)

    if event_type == 'ping':
        print('ping received')
    elif event_type == 'release':
        payload = io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8').read()

        payload = json.loads(payload)
        handle(payload)
    else:
        print('Unrecognized event {}'.format(event_type))


def main():
    print('Content-Type: text/plain; charset=utf-8')
    print('')
    sys.stdout.flush()
    try:
        receive()
    except Exception as e:
        print('Unexpected exception: {}'.format(e))


if __name__ == '__main__':
    main()