Prevent push to Upstream Git

pre-push.py

#!/usr/bin/env python3

import argparse

DISALLOWED_PUSH = ['upstream']


def assert_safe_push(remote, branch):
    if remote in DISALLOWED_PUSH:
        print('Error: push to {remote} is not allowed'.format(**{'remote': remote}))
        exit(1)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('remote')
    parser.add_argument('branch')
    args = parser.parse_args()
    assert_safe_push(args.remote, args.branch)


if __name__ == '__main__':
    main()

Edit the DISALLOWED_PUSH variable to prevent pushes to any repo(s) that you want.

Installation

1. Copy this into your repo's .git/hooks/ directory
2. Rename it to pre-push: mv pre-push.py pre-push
3. Make it executable: chmod +x pre-push