split-repo.py

import click
from subprocess import run
import os


@click.command()
@click.argument("source_repo", type=str)
@click.argument("source_branch", default="master", type=str)
@click.argument("target_repo", type=str)
@click.argument("target_directory", type=str)
@click.argument("target_branch", type=str, default="master")
def main(
    source_repo: str,
    source_branch: str,
    target_repo: str,
    target_directory: str,
    target_branch: str,
):
    """Extract directory from repo and push it new repo with full history.

    Args:
        source_repo (str): url to source repo
        source_branch (str): source repo branch
        target_repo (str): url to target repo
        target_directory (str): directory to be extracted
        target_branch (str): branch for the target
    """

    run(["git", "clone", source_repo, target_directory])
    os.chdir(target_directory)

    if source_branch != "master":
        run(["git", "checkout", f"origin/{source_branch}"])
        run(["git", "checkout", "-b", source_branch])

    run(
        [
            "git",
            "filter-branch",
            "--prune-empty",
            "--subdirectory-filter",
            target_directory,
            source_branch,
        ]
    )

    for line in run(
        ["git", "remote", "-v"], capture_output=True, text=True
    ).stdout.splitlines():
        if source_repo not in line:
            click.echo(
                f"Source repo origins are not matching given source repo, bailing... {source_repo} not in {line}",
                err=True,
            )
            return

    run(["git", "remote", "set-url", "origin", target_repo])

    for line in run(
        ["git", "remote", "-v"], capture_output=True, text=True
    ).stdout.splitlines():
        if target_repo not in line:
            click.echo(
                f"Target repo origins are not matching given target repo, bailing... {source_repo} not in {line}",
                err=True,
            )
            return

    if source_branch != target_branch:
        run(["git", "branch", "-m", target_branch, f"{target_branch}-old"])
        run(["git", "branch", "-m", source_branch, target_branch])

    run(["git", "push", "-u", "origin", target_branch])


if __name__ == "__main__":
    main()