Mini Shell
#!/usr/bin/python3
"""Tool for manipulating the nfsdcld sqlite database
"""
__copyright__ = """
Copyright (C) 2019 Scott Mayhew <smayhew@redhat.com>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
"""
import argparse
import os
import sqlite3
import sys
class CldDb():
def __init__(self, path):
self.con = sqlite3.connect(path)
self.con.row_factory = sqlite3.Row
for row in self.con.execute('select value from parameters '
'where key = "version"'):
self.version = int(row['value'])
for row in self.con.execute('select * from grace'):
self.current = int(row['current'])
self.recovery = int(row['recovery'])
def __del__(self):
self.con.close()
def __str__(self):
return ('Schema version: {self.version} '
'current epoch: {self.current} '
'recovery epoch: {self.recovery}'.format(self=self))
def _print_clients(self, epoch):
if epoch:
for row in self.con.execute('select * from "rec-{:016x}"'
.format(epoch)):
if self.version >= 4:
if row['princhash'] is not None:
princhash = row['princhash'].hex()
else:
princhash = "(null)"
print('id = {}, princhash = {}'
.format(row['id'].decode(), princhash))
else:
print('id = {}'.format(row['id'].decode()))
def print_current_clients(self):
print('Clients in current epoch:')
self._print_clients(self.current)
def print_recovery_clients(self):
if self.recovery:
print('Clients in recovery epoch:')
self._print_clients(self.recovery)
def check_bad_table_names(self):
bad_names = []
for row in self.con.execute('select name from sqlite_master '
'where type = "table" '
'and name like "%rec-%" '
'and length(name) < 20'):
bad_names.append(row['name'])
return bad_names
def fix_bad_table_names(self):
try:
self.con.execute('begin exclusive transaction')
bad_names = self.check_bad_table_names()
for bad_name in bad_names:
epoch = int(bad_name.split('-')[1], base=16)
if epoch == self.current or epoch == self.recovery:
if epoch == self.current:
which = 'current'
else:
which = 'recovery'
print('found invalid table name {} for {} epoch'
.format(bad_name, which))
self.con.execute('alter table "{}" '
'rename to "rec-{:016x}"'
.format(bad_name, epoch))
print('renamed to rec-{:016x}'.format(epoch))
else:
print('found invalid table name {} for unknown epoch {}'
.format(bad_name, epoch))
self.con.execute('drop table "{}"'.format(bad_name))
print('dropped table {}'.format(bad_name))
except sqlite3.Error:
self.con.rollback()
else:
self.con.commit()
def has_princ_data(self):
if self.version < 4:
return False
for row in self.con.execute('select count(*) '
'from "rec-{:016x}" '
'where princhash not null'
.format(self.current)):
count = row[0]
if self.recovery:
for row in self.con.execute('select count(*) '
'from "rec-{:016x}" '
'where princhash not null'
.format(self.current)):
count = count + row[0]
if count:
return True
return False
def _downgrade_table_v4_to_v3(self, epoch):
if not self.con.in_transaction:
raise sqlite3.Error
try:
self.con.execute('create table "new_rec-{:016x}" '
'(id blob primary key)'.format(epoch))
self.con.execute('insert into "new_rec-{:016x}" '
'select id from "rec-{:016x}"'
.format(epoch, epoch))
self.con.execute('drop table "rec-{:016x}"'.format(epoch))
self.con.execute('alter table "new_rec-{:016x}" '
'rename to "rec-{:016x}"'
.format(epoch, epoch))
except sqlite3.Error:
raise
def downgrade_schema_v4_to_v3(self):
try:
self.con.execute('begin exclusive transaction')
for row in self.con.execute('select value from parameters '
'where key = "version"'):
version = int(row['value'])
if version != self.version:
raise sqlite3.Error
for row in self.con.execute('select * from grace'):
current = int(row['current'])
recovery = int(row['recovery'])
if current != self.current:
raise sqlite3.Error
if recovery != self.recovery:
raise sqlite3.Error
self._downgrade_table_v4_to_v3(current)
if recovery:
self._downgrade_table_v4_to_v3(recovery)
self.con.execute('update parameters '
'set value = "3" '
'where key = "version"')
self.version = 3
except sqlite3.Error:
self.con.rollback()
print('Downgrade failed')
else:
self.con.commit()
print('Downgrade successful')
def nfsdcld_active():
rc = os.system('ps -C nfsdcld >/dev/null 2>/dev/null')
if rc == 0:
return True
return False
def fix_table_names_command(db, args):
if nfsdcld_active():
print('Warning: nfsdcld is running!')
ans = input('Continue? ')
if ans.lower() not in ['y', 'yes']:
print('Operation canceled.')
return
bad_names = db.check_bad_table_names()
if not bad_names:
print('No invalid table names found.')
return
db.fix_bad_table_names()
def downgrade_schema_command(db, args):
if nfsdcld_active():
print('Warning: nfsdcld is running!')
ans = input('Continue? ')
if ans.lower() not in ['y', 'yes']:
print('Operation canceled')
return
if db.version != 4:
print('Cannot downgrade database from schema version {}.'
.format(db.version))
return
if args.version != 3:
print('Cannot downgrade to version {}.'.format(args.version))
return
bad_names = db.check_bad_table_names()
if bad_names:
print('Invalid table names detected.')
print('Please run "{} fix-table-names" before downgrading the schema.'
.format(sys.argv[0]))
return
if db.has_princ_data():
print('Warning: database has principal data, which will be erased.')
ans = input('Continue? ')
if ans.lower() not in ['y', 'yes']:
print('Operation canceled')
return
db.downgrade_schema_v4_to_v3()
def print_command(db, args):
print(str(db))
if not args.summary:
bad_names = db.check_bad_table_names()
if bad_names:
print('Invalid table names detected.')
print('Please run "{} fix-table-names".'.format(sys.argv[0]))
return
db.print_current_clients()
db.print_recovery_clients()
def main():
parser = argparse.ArgumentParser()
parser.add_argument('-p', '--path',
default='/var/lib/nfs/nfsdcld/main.sqlite',
help='path to the database '
'(default: /var/lib/nfs/nfsdcld/main.sqlite)')
subparsers = parser.add_subparsers(help='sub-command help')
fix_parser = subparsers.add_parser('fix-table-names',
help='fix invalid table names')
fix_parser.set_defaults(func=fix_table_names_command)
downgrade_parser = subparsers.add_parser('downgrade-schema',
help='downgrade database schema')
downgrade_parser.add_argument('-v', '--version', type=int, choices=[3],
default=3,
help='version to downgrade to')
downgrade_parser.set_defaults(func=downgrade_schema_command)
print_parser = subparsers.add_parser('print',
help='print database info')
print_parser.add_argument('-s', '--summary', default=False,
action='store_true',
help='print summary only')
print_parser.set_defaults(func=print_command)
args = parser.parse_args()
if not os.path.exists(args.path):
return parser.print_usage()
clddb = CldDb(args.path)
return args.func(clddb, args)
if __name__ == '__main__':
if len(sys.argv) == 1:
sys.argv.extend(['print', '--summary'])
main()
Zerion Mini Shell 1.0