git-repo-sign-with-ssh

#!/usr/bin/env python3

import sys
import os
import subprocess

def run(cmd_args):
    sys.stderr.write('%r\n' % cmd_args)
    subprocess.check_call(cmd_args)

def run_stdout(cmd_args):
    p = subprocess.run(cmd_args, capture_output=True, encoding='utf8', check=True)
    return p.stdout

def program_name():
    return os.path.basename(sys.argv[0])

def main(args):
    n = program_name()

    signing_key = run_stdout(['git', 'config', '--local', 'user.signingkey'])
    if not signing_key.strip():
        signing_key = run_stdout(['git', 'config', '--local', 'user.signingkey', '~/.ssh/id_ed25519-scottt.tw-2023.pub'])

    run(['git', 'config', 'commit.gpgsign', 'true'])
    run(['git', 'config', 'gpg.format', 'ssh'])

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