Discussion on: Postgres backup using Docker

#!/bin/sh

echo "$(date): backup process started"
echo "$(date): pg_dump started for ${POSTGRES_DB}"

export BACKUP_ROOT=/backups

FILE=$BACKUP_ROOT/$POSTGRES_DB-$(date +\%FT\%H-%M-%S).sql.gz
pg_dump | /bin/gzip > $FILE

echo "$(date): pg_dump completed"

python3 del.py

echo "$(date): deleted similar files / cluttered old files"

import os
import filecmp
from datetime import datetime, timedelta

os.chdir(os.environ["BACKUP_ROOT"])

latest, *recent = sorted(os.listdir())[::-1]
latest_ctime = datetime.fromtimestamp(os.stat(latest).st_ctime)

previous_file_ctime = latest_ctime
for f in recent:
  ctime = datetime.fromtimestamp(os.stat(f).st_ctime)

  if latest_ctime - ctime < timedelta(days=7):
    if filecmp.cmp(latest, f):
      os.unlink(f)  # Remove similar files
  elif previous_file_ctime - ctime < timedelta(days=7):
    os.unlink(f)  # Remove less than 1 week apart
  elif latest_ctime - ctime < timedelta(days=180):
    os.unlink(f)  # Remove older than 180 days

  previous_file_ctime = ctime