Coverage for python/lsst/daf/butler/registry/connectionString.py : 27%

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1# This file is part of daf_butler.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
22__all__ = ("DB_AUTH_ENVVAR", "DB_AUTH_PATH", "ConnectionStringFactory")
24from sqlalchemy.engine import url
25from ._dbAuth import DbAuth, DbAuthNotFoundError
27DB_AUTH_ENVVAR = "LSST_DB_AUTH"
28"""Default name of the environmental variable that will be used to locate DB
29credentials configuration file. """
31DB_AUTH_PATH = "~/.lsst/db-auth.yaml"
32"""Default path at which it is expected that DB credentials are found."""
35class ConnectionStringFactory:
36 """Factory for `sqlalchemy.engine.url.URL` instances.
38 The factory constructs a connection string URL object by parsing the
39 connection string, the 'db' key in the registry configuration.
40 Username, password, host, port or database can be specified as keys in the
41 config explicitly. If username or password are missing a matching DB is
42 found in the credentials file pointed to by `DB_AUTH_ENVVAR` or
43 `DB_AUTH_PATH` values.
44 """
46 keys = ('username', 'password', 'host', 'port', 'database')
48 @classmethod
49 def fromConfig(cls, registryConfig):
50 """Parses the `db`, and, if they exist, username, password, host, port
51 and database keys from the given config.
53 If no username and password are found in the connection string, or in
54 the config, they are retrieved from a file at `DB_AUTH_PATH` or
55 `DB_AUTH_ENVVAR`. Sqlite dialect does not require a password.
57 The `db` key value of the given config specifies the default connection
58 string, such that if no additional connection string parameters are
59 provided or retrieved, the `db` key is returned unmodified.
61 Parameters
62 ----------
63 config : `ButlerConfig`, `RegistryConfig`, `Config` or `str`
64 Registry configuration
66 Returns
67 -------
68 connectionString : `sqlalchemy.engine.url.URL`
69 URL object representing the connection string.
71 Raises
72 ------
73 DbAuthPermissionsError
74 If the credentials file has incorrect permissions.
75 DbAuthError
76 A problem occured when retrieving DB authentication.
78 Notes
79 -----
80 Matching requires dialect, host and database keys. If dialect is not
81 specified in the db string and host and database keys are not found in
82 the db string, or as explicit keys in the config, the matcher returns
83 an unchanged connection string.
84 Insufficiently specified connection strings are interpreted as an
85 indication that a 3rd party authentication mechanism, such as Oracle
86 Wallet, is being used and therefore are left unmodified.
87 """
88 # this import can not live on the top because of circular import issue
89 from lsst.daf.butler.registry import RegistryConfig
90 regConf = RegistryConfig(registryConfig)
91 conStr = url.make_url(regConf['db'])
93 for key in cls.keys:
94 if getattr(conStr, key) is None:
95 setattr(conStr, key, regConf.get(key))
97 # Allow 3rd party authentication mechanisms by assuming connection
98 # string is correct when we can not recognize (dialect, host, database)
99 # matching keys.
100 if any((conStr.drivername is None,
101 conStr.host is None,
102 conStr.database is None)):
103 return conStr
105 # Ignore when credentials are not set up, or when no matches are found
106 try:
107 dbAuth = DbAuth(DB_AUTH_PATH, DB_AUTH_ENVVAR)
108 auth = dbAuth.getAuth(conStr.drivername, conStr.username, conStr.host,
109 conStr.port, conStr.database)
110 except DbAuthNotFoundError:
111 # credentials file doesn't exist or no matches were found
112 pass
113 else:
114 # only assign auth when *no* errors were raised
115 conStr.username = auth[0]
116 conStr.password = auth[1]
118 return conStr