Add host to known hosts by GIT url - supports both https and ssh url / to be used with eg. Ansible

add-known-host-by-git-url.py

#!/usr/bin/env python3

# Apache License 2.0
#
# Read full license text at: http://www.apache.org/licenses/LICENSE-2.0
# Copyleft (c) 2020 RiotKit Tech Collective
#
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import re
import sys
import os
import subprocess
from urllib.parse import urlparse


def get_known_host(url: str):
    if url.startswith('http'):
        return urlparse(url).netloc
    else:
        match = re.findall('@([A-Za-z-0-9.-_]+):', url)
        return match[0]


def should_append_to_known_hosts(host: str):
    path = os.path.expanduser('~/.ssh/known_hosts')

    if not os.path.isfile(path):
        return True

    patterns = [
        host + ',',
        host + ']:',
        host + ' '
    ]

    with open(path, 'rb') as f:
        content = f.read().decode('utf-8')

        for pattern in patterns:
            if pattern in content:
                return False

    return True


def main(url: str):
    host = get_known_host(url)

    if should_append_to_known_hosts(host):
        try:
            subprocess.check_call('ssh-keyscan -t rsa %s >> ~/.ssh/known_hosts' % host, shell=True)
        except subprocess.CalledProcessError as e:
            print(str(e))
            sys.exit(1)


if __name__ == '__main__':
    main(sys.argv[1])
    sys.exit(0)