How to Implement a Vault Dynamic Database Credentials Mock in Python

import time
import json
from dataclasses import dataclass, field
from typing import Dict


@dataclass
class DynamicCredential:
    username: str
    password: str
    lease_duration: int
    created_at: float = field(default_factory=time.time)

    def is_valid(self) -> bool:
        return time.time() - self.created_at < self.lease_duration

    def to_dict(self) -> Dict[str, str]:
        return {
            "username": self.username,
            "password": self.password,
            "lease_duration": str(self.lease_duration),
            "created_at": str(self.created_at),
            "valid": str(self.is_valid()),
        }


class VaultMock:
    def __init__(self):
        self._credentials: Dict[str, DynamicCredential] = {}

    def create_database_creds(self, role: str, lease_duration: int = 3600) -> DynamicCredential:
        cred = DynamicCredential(
            username=f"v-{role}-{int(time.time())}",
            password="generated-password-" + str(abs(hash(role)))[:8],
            lease_duration=lease_duration,
        )
        self._credentials[cred.username] = cred
        return cred

    def revoke_creds(self, username: str) -> bool:
        return self._credentials.pop(username, None) is not None

    def list_active(self) -> list[str]:
        return [u for u, c in self._credentials.items() if c.is_valid()]


if __name__ == "__main__":
    vault = VaultMock()
    db_creds = vault.create_database_creds("readonly", lease_duration=5)
    print(json.dumps(db_creds.to_dict(), indent=2))

    print("Active:", vault.list_active())
    time.sleep(6)
    print("After expiry, active:", vault.list_active())
    print("Revoked:", vault.revoke_creds(db_creds.username))