Coverage for python/lsst/daf/butler/registry/_dbAuth.py : 11%

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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/>.
22import fnmatch
23import os
24import stat
25import urllib.parse
26import yaml
28__all__ = ["DbAuth", "DbAuthError", "DbAuthPermissionsError"]
31class DbAuthError(RuntimeError):
32 """A problem has occurred retrieving database authentication information.
33 """
34 pass
37class DbAuthNotFoundError(DbAuthError):
38 """Credentials file does not exist or no match was found in it."""
41class DbAuthPermissionsError(DbAuthError):
42 """Credentials file has incorrect permissions."""
45class DbAuth:
46 """Retrieves authentication information for database connections.
48 The authorization configuration is taken from the ``authList`` parameter
49 or a (group- and world-inaccessible) YAML file located at a path specified
50 by the given environment variable or at a default path location.
52 Parameters
53 ----------
54 path : `str` or None, optional
55 Path to configuration file.
56 envVar : `str` or None, optional
57 Name of environment variable pointing to configuration file.
58 authList : `list` [`dict`] or None, optional
59 Authentication configuration.
61 Notes
62 -----
63 At least one of ``path``, ``envVar``, or ``authList`` must be provided;
64 generally ``path`` should be provided as a default location.
65 """
66 def __init__(self, path=None, envVar=None, authList=None):
67 if authList is not None:
68 self.authList = authList
69 return
70 if envVar is not None and envVar in os.environ:
71 secretPath = os.path.expanduser(os.environ[envVar])
72 elif path is None:
73 raise DbAuthNotFoundError(
74 "No default path provided to DbAuth configuration file")
75 else:
76 secretPath = os.path.expanduser(path)
77 if not os.path.isfile(secretPath):
78 raise DbAuthNotFoundError(f"No DbAuth configuration file: {secretPath}")
79 mode = os.stat(secretPath).st_mode
80 if mode & (stat.S_IRWXG | stat.S_IRWXO) != 0:
81 raise DbAuthPermissionsError(
82 "DbAuth configuration file {} has incorrect permissions: "
83 "{:o}".format(secretPath, mode))
85 try:
86 with open(secretPath) as secretFile:
87 self.authList = yaml.safe_load(secretFile)
88 except Exception as exc:
89 raise DbAuthError(f"Unable to load DbAuth configuration file: {secretPath}.") from exc
91 def getAuth(self, drivername, username, host, port, database):
92 """Retrieve a username and password for a database connection.
94 This function matches elements from the database connection URL with
95 glob-like URL patterns in a list of configuration dictionaries.
97 Parameters
98 ----------
99 drivername : `str`
100 Name of database backend driver from connection URL.
101 username : `str` or None
102 Username from connection URL if present.
103 host : `str`
104 Host name from connection URL if present.
105 port : `str` or `int` or None
106 Port from connection URL if present.
107 database : `str`
108 Database name from connection URL.
110 Returns
111 -------
112 username: `str`
113 Username to use for database connection; same as parameter if
114 present.
115 password: `str`
116 Password to use for database connection.
118 Raises
119 ------
120 DbAuthError
121 Raised if the input is missing elements, an authorization
122 dictionary is missing elements, the authorization file is
123 misconfigured, or no matching authorization is found.
125 Notes
126 -----
127 The list of authorization configuration dictionaries is tested in
128 order, with the first matching dictionary used. Each dictionary must
129 contain a ``url`` item with a pattern to match against the database
130 connection URL and a ``password`` item. If no username is provided in
131 the database connection URL, the dictionary must also contain a
132 ``username`` item.
134 Glob-style patterns (using "``*``" and "``?``" as wildcards) can be
135 used to match the host and database name portions of the connection
136 URL. For the username, port, and database name portions, omitting them
137 from the pattern matches against any value in the connection URL.
139 Examples
140 --------
142 The connection URL
143 ``postgresql://user@host.example.com:5432/my_database`` matches against
144 the identical string as a pattern. Other patterns that would match
145 include:
147 * ``postgresql://*``
148 * ``postgresql://*.example.com``
149 * ``postgresql://*.example.com/my_*``
150 * ``postgresql://host.example.com/my_database``
151 * ``postgresql://host.example.com:5432/my_database``
152 * ``postgresql://user@host.example.com/my_database``
154 Note that the connection URL
155 ``postgresql://host.example.com/my_database`` would not match against
156 the pattern ``postgresql://host.example.com:5432``, even if the default
157 port for the connection is 5432.
158 """
159 if drivername is None or drivername == "":
160 raise DbAuthError("Missing drivername parameter")
161 if host is None or host == "":
162 raise DbAuthError("Missing host parameter")
163 if database is None or database == "":
164 raise DbAuthError("Missing database parameter")
166 for authDict in self.authList:
168 # Check for mandatory entries
169 if "url" not in authDict:
170 raise DbAuthError("Missing URL in DbAuth configuration")
172 # Parse pseudo-URL from db-auth.yaml
173 components = urllib.parse.urlparse(authDict["url"])
175 # Check for same database backend type/driver
176 if components.scheme == "":
177 raise DbAuthError(
178 "Missing database driver in URL: " + authDict["url"])
179 if drivername != components.scheme:
180 continue
182 # Check for same database name
183 if components.path != "" and components.path != "/":
184 if not fnmatch.fnmatch(database, components.path.lstrip("/")):
185 continue
187 # Check username
188 if components.username is not None:
189 if username is None or username == "":
190 continue
191 if username != components.username:
192 continue
194 # Check hostname
195 if components.hostname is None:
196 raise DbAuthError("Missing host in URL: " + authDict["url"])
197 if not fnmatch.fnmatch(host, components.hostname):
198 continue
200 # Check port
201 if components.port is not None and \
202 (port is None or str(port) != str(components.port)):
203 continue
205 # Don't override username from connection string
206 if username is not None and username != "":
207 return (username, authDict["password"])
208 else:
209 if "username" not in authDict:
210 return (None, authDict["password"])
211 return (authDict["username"], authDict["password"])
213 raise DbAuthNotFoundError(
214 "No matching DbAuth configuration for: "
215 f"({drivername}, {username}, {host}, {port}, {database})")
217 def getUrl(self, url):
218 """Fill in a username and password in a database connection URL.
220 This function parses the URL and calls `getAuth`.
222 Parameters
223 ----------
224 url : `str`
225 Database connection URL.
227 Returns
228 -------
229 url : `str`
230 Database connection URL with username and password.
232 Raises
233 ------
234 DbAuthError
235 Raised if the input is missing elements, an authorization
236 dictionary is missing elements, the authorization file is
237 misconfigured, or no matching authorization is found.
239 See also
240 --------
241 getAuth
242 """
243 components = urllib.parse.urlparse(url)
244 username, password = self.getAuth(
245 components.scheme,
246 components.username, components.hostname, components.port,
247 components.path.lstrip("/"))
248 hostname = components.hostname
249 if ":" in hostname: # ipv6
250 hostname = f"[{hostname}]"
251 netloc = "{}:{}@{}".format(
252 urllib.parse.quote(username, safe=""),
253 urllib.parse.quote(password, safe=""), hostname)
254 if components.port is not None:
255 netloc += ":" + str(components.port)
256 return urllib.parse.urlunparse((
257 components.scheme, netloc, components.path, components.params,
258 components.query, components.fragment))