lua-resty-auto-ssl: Delete expired (or near expired) certs from redis

cert_cleanup.py

import redis
import json
from datetime import datetime, timedelta
from redis.exceptions import ResponseError

r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)

now = datetime.now()
three_days_from_now = now + timedelta(days=3)
keys_to_purge = []
flagged_key_count = 0
valid_key_count = 0

print("")
print("======== %s ========" % now.strftime('%m/%d/%Y, %H:%M:%S'))

for key in r.scan_iter():
    try:
        cert_data = r.get(key)
        cert_dict = json.loads(cert_data)
        expiry = cert_dict.get('expiry', None)
        if expiry:
            key_expires_on = datetime.fromtimestamp(expiry)

            # Sanity check in case the 'expiry' format changes in the future
            # Validates timestamp between 2017 - 2030
            if expiry < 1500000000 or expiry > 1900000000:
                raise Exception("Invalid Timestamp Detected. Aborting")
            
            if key_expires_on < three_days_from_now:
                print("Key %s is expiring within 3 days. Adding to purge list" % key)
                keys_to_purge.append(key)
                flagged_key_count += 1
            else:
                valid_key_count += 1
    except ResponseError:
        # Wrong datatype - skip
        # print("Invalid datatype for key ", key)
        continue
    except json.decoder.JSONDecodeError:
        print("Warn: Unable to decode %s. Possibly a challenge key." % key)
    except Exception as e:
        print("Failed on Key %s" % key)
        raise e

print("Flagged Key Count:", flagged_key_count)
print("Valid Key Count:", valid_key_count)

# Purge keys marked to purge, but first, more validation
if len(keys_to_purge) > 25:
    raise Exception("Too many keys (%s) will be purged with this operation. Aborting." % len(keys_to_purge))
else:
    # Purge Keys
    for key in keys_to_purge:
        print("Deleting", key)
        r.delete(key)