Create a gridmapdir from a groupmap file and accounts

make_gridmapdir.py

#!/usr/bin/env python3
from typing import NamedTuple, Iterable, Dict, List

import argparse
import pathlib
import re


CLI = argparse.ArgumentParser()
CLI.add_argument(
    "--gridmapfile",
    help="path to gridmapfile",
    default="/etc/grid-security/grid-mapfile",
    type=pathlib.Path,
)
CLI.add_argument(
    "--gridmapdir",
    help="path to gridmapdir",
    default="/etc/grid-security/gridmapdir/",
    type=pathlib.Path,
)
CLI.add_argument(
    "-n",
    "--no-op",
    help="only report actions, do not perform them",
    action="store_true",
)


class Group(NamedTuple):
    pattern: str
    pool_name: str


def get_groups(gridmapfile: pathlib.Path) -> Iterable[Group]:
    with gridmapfile.open() as groupmap:
        for line in map(str.strip, groupmap):
            if not line:
                continue
            pattern, basename = line.rsplit(None, 1)
            if basename[0] == '.':
                yield Group(pattern=pattern, pool_name=basename[1:])


def get_accounts() -> Dict[str, List[str]]:
    pool_pattern = re.compile(r"^(\w+?)(\d+)$")
    pools: Dict[str, List[str]] = {}
    with open("/etc/passwd") as passwd:
        for line in map(str.strip, passwd):
            if not line:
                continue
            name, *_ = line.split(":", 1)
            try:
                pool_name, number = pool_pattern.match(name).groups()
            except AttributeError:
                continue
            else:
                pools.setdefault(pool_name, []).append(name)
    return {pool_name: sorted(names) for pool_name, names in pools.items()}


def create_accountmap(path: pathlib.Path):
    try:
        path.touch(exist_ok=False)
    except FileExistsError:
        return False
    else:
        return True


def create_accountmap_noop(path: pathlib.Path):
    return not path.exists()


def ensure_gridmap(gridmapfile: pathlib.Path, gridmapdir: pathlib.Path, no_op=True):
    groups = {group.pool_name for group in get_groups(gridmapfile)}
    accounts = get_accounts()
    ensure_account = create_accountmap_noop if no_op else create_accountmap
    for group in groups:
        created = existed = 0
        total = len(accounts.get(group, []))
        print("Ensuring", group, f"[{total}]")
        for account in accounts.get(group, []):
            path = gridmapdir / account
            if ensure_account(path):
                print("++ create:", path)
                created += 1
            else:
                print("== exists:", path, end="\r")
                existed += 1
        print(f"=============================== [{created} / {total}] ====")


def main():
    options = CLI.parse_args()
    ensure_gridmap(
        gridmapfile=options.gridmapfile,
        gridmapdir=options.gridmapdir,
        no_op=options.no_op,
    )


if __name__ == "__main__":
    main()