backup-tool/app/__main__.py

import argparse
import sys
from parser import read_specs_file


# Define parser
parser = argparse.ArgumentParser(
    description="Backup directories and Docker volumes."
)
parser.add_argument(
    "-f",
    "--file",
    action="append",
    dest="file",
    required=True,
    help="File containing spec definitions.",
)
parser.add_argument(
    "-j",
    "--json",
    action="store_const",
    const=True,
    default=False,
    help="Print out the parsed specs as JSON and exit",
)
parser.add_argument(
    "spec", nargs="*", help="The specs to process. Defaults to all."
)

# Parse arguments
args = parser.parse_args()
specs = sum([read_specs_file(path) for path in args.file], [])

# Filter specs if needed
if args.spec:
    specs = list(filter(lambda s: s.name in args.spec, specs))

# Dump parsed data as json
if args.json:
    import json

    print(json.dumps([spec.to_dict() for spec in specs], indent=4))

else:
    # Run the backups
    if not specs:
        print("No specs, exiting.")
        sys.exit(0)

    for spec in specs:
        spec.backup()