Files
jobtrackingapp/scripts/parse-backup-connection.py
T

69 lines
3.1 KiB
Python

"""Read a deployment connection string from stdin; emit five fields plus a sentinel.
This is a single-host dump contract, not a replacement for MySqlConnector. Reject
ambiguous aliases/control characters instead of choosing a different backup target.
Never include input values in errors or pass the connection string as an argument.
"""
import re
import sys
ALIASES = {
**dict.fromkeys(['server', 'host', 'data source', 'datasource', 'address', 'addr', 'network address'], 'host'),
**dict.fromkeys(['user id', 'userid', 'username', 'uid', 'user name', 'user'], 'user'),
**dict.fromkeys(['password', 'pwd'], 'password'),
**dict.fromkeys(['database', 'initial catalog'], 'database'),
'port': 'port',
}
PAIR = re.compile(r'''\s*([^=;]+?)\s*=\s*(?:"((?:""|[^"])*)"|'((?:''|[^'])*)'|([^;]*))\s*(?:;|$)''')
def parse(connection):
if any(ord(c) < 32 or ord(c) == 127 for c in connection):
raise ValueError('Control characters are unsupported in backup connection settings.')
fields = {}
position = 0
while position < len(connection):
if connection[position] == ';' or connection[position].isspace():
position += 1
continue
match = PAIR.match(connection, position)
if not match:
raise ValueError('Malformed backup connection settings.')
key, double, single, plain = match.groups()
if double is not None:
value = double.replace('""', '"')
elif single is not None:
value = single.replace("''", "'")
else:
value = plain.strip()
if value.startswith(('"', "'")):
raise ValueError('Malformed quoted backup connection value.')
canonical = ALIASES.get(key.strip().lower())
if canonical:
if canonical in fields:
raise ValueError('Duplicate backup connection setting or alias.')
fields[canonical] = value
position = match.end()
if any(not fields.get(key, '').strip() for key in ['host', 'database', 'user']):
raise ValueError('Backup connection requires host, database and user.')
port = fields.get('port', '3306')
if not re.fullmatch(r'[0-9]+', port) or not 1 <= int(port) <= 65535:
raise ValueError('Backup connection port must be between 1 and 65535.')
if any(c in fields['host'] for c in ',/\\'):
raise ValueError('Backup requires one TCP host, not a host list or socket path.')
if any(c in fields['database'] for c in '/\\'):
raise ValueError('Database name cannot contain backup path separators.')
return [fields['host'], str(int(port)), fields['database'], fields['user'], fields.get('password', '')]
if __name__ == '__main__':
try:
values = parse(sys.stdin.buffer.read().decode('utf-8'))
except (ValueError, UnicodeError):
print('Invalid or unsupported backup connection settings.', file=sys.stderr)
sys.exit(1)
sys.stdout.reconfigure(encoding='utf-8', newline='\n')
# Sentinel keeps an empty final password intact through shell command substitution.
sys.stdout.write('\n'.join([*values, 'END']) + '\n')