Docker context import script

docker_import.py

from pathlib import Path
import subprocess
import click
import os
import sys

REQUIRED_FILES = ["cert.pem", "ca.pem", "key.pem"]

def get_user_data_dir(app_name: str) -> Path:
    """
    Return a cross-platform directory for storing user-specific application data.
    """
    if sys.platform == "win32":
        base = Path(os.environ.get("APPDATA", Path.home() / "AppData" / "Roaming"))
    elif sys.platform == "darwin":
        base = Path.home() / "Library" / "Application Support"
    else:
        base = Path(os.environ.get("XDG_DATA_HOME", Path.home() / ".local" / "share"))

    return base / app_name

@click.command()
@click.argument(
    "root_dir",
    type=click.Path(exists=True, file_okay=False, dir_okay=True, path_type=Path)
)
def main(root_dir: Path):
    """
    Create Docker contexts for hosts under ROOT_DIR using TLS certificates.
    Copies certificates into a user-data directory for safe reference.
    """
    click.echo(f"Scanning root directory: {root_dir}")

    local_base_dir = get_user_data_dir("docker_contexts")
    local_base_dir.mkdir(parents=True, exist_ok=True)

    for host_path in root_dir.iterdir():
        if not host_path.is_dir():
            continue  # skip files

        host_name = host_path.name

        # Validate required files
        missing = [f for f in REQUIRED_FILES if not (host_path / f).is_file()]
        if missing:
            click.secho(f"Skipping {host_name}, missing files: {', '.join(missing)}", fg="red")
            continue

        # Copy certificates to user-data directory
        local_host_dir = local_base_dir / host_name
        local_host_dir.mkdir(parents=True, exist_ok=True)

        for f in REQUIRED_FILES:
            src_file = host_path / f
            dst_file = local_host_dir / f
            dst_file.write_bytes(src_file.read_bytes())

        # Build docker context create command
        ca = local_host_dir / "ca.pem"
        cert = local_host_dir / "cert.pem"
        key = local_host_dir / "key.pem"

        cmd = [
            "docker", "context", "create", host_name,
            "--docker",
            f"host=tcp://{host_name}:2376,ca={ca},cert={cert},key={key}"
        ]

        click.secho(f"Creating Docker context for host: {host_name}", fg="green")
        try:
            subprocess.run(cmd, check=True)
            click.secho(f"Context {host_name} created successfully ✅", fg="green")
        except subprocess.CalledProcessError as e:
            click.secho(f"Failed to create context for {host_name}: {e}", fg="red")

if __name__ == "__main__":
    main()