borgmatic/borgmatic/hooks/mysql.py

226 lines
8.9 KiB
Python

import copy
import logging
import os
from borgmatic.execute import (
execute_command,
execute_command_and_capture_output,
execute_command_with_processes,
)
from borgmatic.hooks import dump
logger = logging.getLogger(__name__)
def make_dump_path(location_config): # pragma: no cover
'''
Make the dump path from the given location configuration and the name of this hook.
'''
return dump.make_database_dump_path(
location_config.get('borgmatic_source_directory'), 'mysql_databases'
)
SYSTEM_DATABASE_NAMES = ('information_schema', 'mysql', 'performance_schema', 'sys')
def database_names_to_dump(database, extra_environment, log_prefix, dry_run):
'''
Given a requested database config, return the corresponding sequence of database names to dump.
In the case of "all", query for the names of databases on the configured host and return them,
excluding any system databases that will cause problems during restore.
'''
if database['name'] != 'all':
return (database['name'],)
if dry_run:
return ()
show_command = (
('mysql',)
+ (tuple(database['list_options'].split(' ')) if 'list_options' in database else ())
+ (('--host', database['hostname']) if 'hostname' in database else ())
+ (('--port', str(database['port'])) if 'port' in database else ())
+ (('--protocol', 'tcp') if 'hostname' in database or 'port' in database else ())
+ (('--user', database['username']) if 'username' in database else ())
+ ('--skip-column-names', '--batch')
+ ('--execute', 'show schemas')
)
logger.debug(f'{log_prefix}: Querying for "all" MySQL databases to dump')
show_output = execute_command_and_capture_output(
show_command, extra_environment=extra_environment
)
return tuple(
show_name
for show_name in show_output.strip().splitlines()
if show_name not in SYSTEM_DATABASE_NAMES
)
def execute_dump_command(
database, log_prefix, dump_path, database_names, extra_environment, dry_run, dry_run_label
):
'''
Kick off a dump for the given MySQL/MariaDB database (provided as a configuration dict) to a
named pipe constructed from the given dump path and database names. Use the given log prefix in
any log entries.
Return a subprocess.Popen instance for the dump process ready to spew to a named pipe. But if
this is a dry run, then don't actually dump anything and return None.
'''
database_name = database['name']
dump_filename = dump.make_database_dump_filename(
dump_path, database['name'], database.get('hostname')
)
if os.path.exists(dump_filename):
logger.warning(
f'{log_prefix}: Skipping duplicate dump of MySQL database "{database_name}" to {dump_filename}'
)
return None
dump_command = (
('mysqldump',)
+ (tuple(database['options'].split(' ')) if 'options' in database else ())
+ (('--add-drop-database',) if database.get('add_drop_database', True) else ())
+ (('--host', database['hostname']) if 'hostname' in database else ())
+ (('--port', str(database['port'])) if 'port' in database else ())
+ (('--protocol', 'tcp') if 'hostname' in database or 'port' in database else ())
+ (('--user', database['username']) if 'username' in database else ())
+ ('--databases',)
+ database_names
# Use shell redirection rather than execute_command(output_file=open(...)) to prevent
# the open() call on a named pipe from hanging the main borgmatic process.
+ ('>', dump_filename)
)
logger.debug(
f'{log_prefix}: Dumping MySQL database "{database_name}" to {dump_filename}{dry_run_label}'
)
if dry_run:
return None
dump.create_named_pipe_for_dump(dump_filename)
return execute_command(
dump_command, shell=True, extra_environment=extra_environment, run_to_completion=False,
)
def dump_databases(databases, log_prefix, location_config, dry_run):
'''
Dump the given MySQL/MariaDB databases to a named pipe. The databases are supplied as a sequence
of dicts, one dict describing each database as per the configuration schema. Use the given log
prefix in any log entries. Use the given location configuration dict to construct the
destination path.
Return a sequence of subprocess.Popen instances for the dump processes ready to spew to a named
pipe. But if this is a dry run, then don't actually dump anything and return an empty sequence.
'''
dry_run_label = ' (dry run; not actually dumping anything)' if dry_run else ''
processes = []
logger.info('{}: Dumping MySQL databases{}'.format(log_prefix, dry_run_label))
for database in databases:
dump_path = make_dump_path(location_config)
extra_environment = {'MYSQL_PWD': database['password']} if 'password' in database else None
dump_database_names = database_names_to_dump(
database, extra_environment, log_prefix, dry_run
)
if not dump_database_names:
if dry_run:
continue
raise ValueError('Cannot find any MySQL databases to dump.')
if database['name'] == 'all' and database.get('format'):
for dump_name in dump_database_names:
renamed_database = copy.copy(database)
renamed_database['name'] = dump_name
processes.append(
execute_dump_command(
renamed_database,
log_prefix,
dump_path,
(dump_name,),
extra_environment,
dry_run,
dry_run_label,
)
)
else:
processes.append(
execute_dump_command(
database,
log_prefix,
dump_path,
dump_database_names,
extra_environment,
dry_run,
dry_run_label,
)
)
return [process for process in processes if process]
def remove_database_dumps(databases, log_prefix, location_config, dry_run): # pragma: no cover
'''
Remove all database dump files for this hook regardless of the given databases. Use the log
prefix in any log entries. Use the given location configuration dict to construct the
destination path. If this is a dry run, then don't actually remove anything.
'''
dump.remove_database_dumps(make_dump_path(location_config), 'MySQL', log_prefix, dry_run)
def make_database_dump_pattern(
databases, log_prefix, location_config, name=None
): # pragma: no cover
'''
Given a sequence of configurations dicts, a prefix to log with, a location configuration dict,
and a database name to match, return the corresponding glob patterns to match the database dump
in an archive.
'''
return dump.make_database_dump_filename(make_dump_path(location_config), name, hostname='*')
def restore_database_dump(database_config, log_prefix, location_config, dry_run, extract_process):
'''
Restore the given MySQL/MariaDB database from an extract stream. The database is supplied as a
one-element sequence containing a dict describing the database, as per the configuration schema.
Use the given log prefix in any log entries. If this is a dry run, then don't actually restore
anything. Trigger the given active extract process (an instance of subprocess.Popen) to produce
output to consume.
'''
dry_run_label = ' (dry run; not actually restoring anything)' if dry_run else ''
if len(database_config) != 1:
raise ValueError('The database configuration value is invalid')
database = database_config[0]
restore_command = (
('mysql', '--batch')
+ (tuple(database['restore_options'].split(' ')) if 'restore_options' in database else ())
+ (('--host', database['hostname']) if 'hostname' in database else ())
+ (('--port', str(database['port'])) if 'port' in database else ())
+ (('--protocol', 'tcp') if 'hostname' in database or 'port' in database else ())
+ (('--user', database['username']) if 'username' in database else ())
)
extra_environment = {'MYSQL_PWD': database['password']} if 'password' in database else None
logger.debug(
'{}: Restoring MySQL database {}{}'.format(log_prefix, database['name'], dry_run_label)
)
if dry_run:
return
# Don't give Borg local path so as to error on warnings, as "borg extract" only gives a warning
# if the restore paths don't exist in the archive.
execute_command_with_processes(
restore_command,
[extract_process],
output_log_level=logging.DEBUG,
input_file=extract_process.stdout,
extra_environment=extra_environment,
)