prune_deleted_nova.py

#!/usr/bin/env python
#
# Prune deleted instance content out of a nova database
#
# Authors: Jesse Keating <[email protected]>
#
# License: MIT

import argparse
import MySQLdb
import os
import sys

def error(msg='An error occurred'):
    # this should probably use logging instead of sys
    sys.stderr.write(msg + '\n')
    sys.exit(1)

# What do I need to know?
# database user, default of root
# database password, default of None
# if no user/pass, read ~/.my.cnf
# database name, default of nova
parser = argparse.ArgumentParser(description='Nova Pruner')
parser.add_argument('--host', default='localhost',
                    help='Host of the database server (default: %(default)s)')
parser.add_argument('--user', help='Login user')
parser.add_argument('--password', help='Login password')
parser.add_argument('--dbname', default='nova',
                    help='Name of the Nova database (default: %(default)s)')

args = parser.parse_args()

# see if we need to mine a my.cnf file
login_user = args.user
login_password = args.password or ''

# create a db object
if login_user:
    db = MySQLdb.connect(host=args.host, db=args.dbname, user=login_user,
                         passwd=login_password)
else:
    mycnf = os.path.expanduser('~/.my.cnf')
    if os.path.exists(mycnf):
        db = MySQLdb.connect(host=args.host, db=args.dbname,
                             read_default_file=mycnf)
    else:
        error(msg='User was not provided, nor is ~/.my.cnf readable.')

# walk through each block of things to delete
## things to delete from
# migrations
# instance_extra
# block_device_mapping
# instance_actions_events
# instance_actions
# instance_info_caches
# instance_system_metadata
# instance_faults
# instances
queries = ["DELETE migrations FROM migrations JOIN instances ON \
           migrations.instance_uuid = instances.uuid WHERE \
           instances.vm_state = %s",
           "DELETE instance_extra from instance_extra JOIN instances ON \
           instance_extra.instance_uuid = instances.uuid WHERE \
           instances.vm_state = %s",
           "DELETE block_device_mapping FROM block_device_mapping JOIN \
           instances ON block_device_mapping.instance_uuid = instances.uuid \
           WHERE instances.vm_state = %s",
           "DELETE instance_actions_events FROM instance_actions_events JOIN \
           instance_actions JOIN instances ON instance_actions.instance_uuid \
           = instances.uuid WHERE instances.vm_state = %s",
           "DELETE instance_actions from instance_actions JOIN instances ON \
           instance_actions.instance_uuid = instances.uuid WHERE \
           instances.vm_state = %s",
           "DELETE instance_info_caches from instance_info_caches JOIN \
           instances ON instance_info_caches.instance_uuid = instances.uuid \
           WHERE instances.vm_state = %s",
           "DELETE instance_system_metadata from instance_system_metadata JOIN \
           instances ON instance_system_metadata.instance_uuid = instances.uuid \
           WHERE instances.vm_state = %s",
           "DELETE instance_faults from instance_faults JOIN instances ON \
           instance_faults.instance_uuid = instances.uuid WHERE \
           instances.vm_state = %s",
           "DELETE from instances where vm_state = %s"]

# get a cursor
curse = db.cursor()

exit_code = 0

# Do all the deletes
try:
    for query in queries:
        curse.execute(query, ('deleted'))

    # commit them all
    db.commit()
except Exception, e:
    sys.stderr.write(e + '\n')
    exit_code = 1
finally:
    curse.close()
    db.close()

sys.exit(exit_code)