delete_obsolete

#!/usr/bin/python

import argparse
import boto3
import datetime
import humanize

import grandfatherson


def delete_obsolete(bucket, pattern, hours, days, weeks, months, years, dryrun=False):
    report = dict()
    b = boto3.resource('s3').Bucket(bucket)
    backups = dict()
    for k in b.objects.all():
        report[k.key] = set()
        try:
            dt = datetime.datetime.strptime(k.key, pattern)
            backups[dt] = k
        except ValueError:
            report[k.key].add('i')
    if len(backups) > 1:
        backup_list = sorted(backups.keys())
        for b in sorted(
                grandfatherson.to_delete(backup_list, hours=hours, days=days, weeks=weeks, months=months, years=years,
                                         now=backup_list[-2])):
            report[backups[b].key].add('d')
            if not dryrun:
                backups[b].delete()
    if dryrun:
        for b in sorted(report):
            flags = ''.join(report[b])
            print '%-3s   %s' % (flags, b)


def list_keys(bucket):
    b = boto3.resource('s3').Bucket(bucket)
    for k in sorted(b.objects.all(), key=lambda x: x.last_modified):
        print '%s   %-8s   %s' % (k.last_modified, humanize.naturalsize(k.size), k.key)


ap = argparse.ArgumentParser(add_help=False)
ap.add_argument('bucket', help='the bucket')
ap.add_argument('--help', action='help')
ap.add_argument('-p', '--pattern', help='strptime pattern of the backup archives')
ap.add_argument('-n', '--dryrun', action='store_true',
                help='don\'t actually delete archives, just show what would be done')
ap.add_argument('-h', '--hours', type=int, default=24, help='hours of backup to retain, default %(default)s')
ap.add_argument('-d', '--days', type=int, default=7, help='days of backup to retain, default %(default)s')
ap.add_argument('-w', '--weeks', type=int, default=3, help='weeks of backup to retain, default %(default)s')
ap.add_argument('-m', '--months', type=int, default=3, help='months of backup to retain, default %(default)s')
ap.add_argument('-y', '--years', type=int, default=1, help='years of backup to retain, default %(default)s')
args = ap.parse_args()

if args.pattern:
    delete_obsolete(args.bucket, args.pattern, args.hours, args.days, args.weeks, args.months, args.years,
                    dryrun=args.dryrun)
else:
    list_keys(args.bucket)