Script para fazer backup/dump de base de dados PostgreSQL

backup-database.py

import argparse
import datetime as dt
import getpass
import os
import subprocess
import zlib
from pathlib import Path


def compute_crc32(filepath: Path) -> dict[str, str]:
    crc = 0
    with open(filepath, "rb") as f:
        while chunk := f.read(8192):
            crc = zlib.crc32(chunk, crc)

    return "{:08X}".format(crc & 0xFFFFFFFF)


def create_backup(username: str, database_name: str, dest_dir: Path):
    now = dt.datetime.now()
    filepath = dest_dir / f"{database_name}-backup-{now:%Y-%m-%d-%H-%M}"
    cmd = [
        "pg_dump",
        "-U",
        username,
        "-d",
        database_name,
        "-f",
        str(filepath),
    ]
    subprocess.run(cmd)
    crc32 = compute_crc32(filepath)
    new_filepath = dest_dir / f"{filepath.name}[{crc32}].sql"
    filepath.rename(new_filepath)
    return new_filepath


def compress(filepath: Path, remove_original: bool = False):
    dest_filepath = filepath.parent / f"{filepath.name}.7z"
    # https://stackoverflow.com/a/28474846
    cmd = [
        "7z",
        "a",
        "-m0=lzma2",
        "-mx=9",
        "-aoa",
        str(dest_filepath.absolute()),
        str(filepath.absolute()),
    ]
    subprocess.run(cmd)
    if remove_original:
        filepath.unlink()


def get_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("-U", "--user", dest="user", required=True)
    parser.add_argument("-d", "--database", dest="database", required=True)
    parser.add_argument("-dest-dir", type=Path, required=True)
    parser.add_argument("--remove-uncompressed-sql", action="store_true")
    return parser.parse_args()


def main():
    args = get_args()
    pgpassword = getpass.getpass(prompt="Password:")
    os.environ.update({"PGPASSWORD": pgpassword})
    filepath = create_backup(
        username=args.user,
        database_name=args.database,
        dest_dir=args.dest_dir,
    )
    compress(filepath, remove_original=args.remove_uncompressed_sql)


if __name__ == "__main__":
    main()