Coverage for python/lsst/daf/butler/registry/_dbAuth.py: 17%

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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/>. 

21 

22from __future__ import annotations 

23 

24import fnmatch 

25import os 

26import stat 

27import urllib.parse 

28from typing import Dict, List, Optional, Tuple, Union 

29 

30import yaml 

31 

32__all__ = ["DbAuth", "DbAuthError", "DbAuthPermissionsError"] 

33 

34 

35class DbAuthError(RuntimeError): 

36 """Exception raised when a problem has occurred retrieving database 

37 authentication information. 

38 """ 

39 

40 pass 

41 

42 

43class DbAuthNotFoundError(DbAuthError): 

44 """Credentials file does not exist or no match was found in it.""" 

45 

46 

47class DbAuthPermissionsError(DbAuthError): 

48 """Credentials file has incorrect permissions.""" 

49 

50 

51class DbAuth: 

52 """Retrieves authentication information for database connections. 

53 

54 The authorization configuration is taken from the ``authList`` parameter 

55 or a (group- and world-inaccessible) YAML file located at a path specified 

56 by the given environment variable or at a default path location. 

57 

58 Parameters 

59 ---------- 

60 path : `str` or None, optional 

61 Path to configuration file. 

62 envVar : `str` or None, optional 

63 Name of environment variable pointing to configuration file. 

64 authList : `list` [`dict`] or None, optional 

65 Authentication configuration. 

66 

67 Notes 

68 ----- 

69 At least one of ``path``, ``envVar``, or ``authList`` must be provided; 

70 generally ``path`` should be provided as a default location. 

71 """ 

72 

73 def __init__( 

74 self, 

75 path: Optional[str] = None, 

76 envVar: Optional[str] = None, 

77 authList: Optional[List[Dict[str, str]]] = None, 

78 ): 

79 if authList is not None: 

80 self.authList = authList 

81 return 

82 if envVar is not None and envVar in os.environ: 

83 secretPath = os.path.expanduser(os.environ[envVar]) 

84 elif path is None: 

85 raise DbAuthNotFoundError("No default path provided to DbAuth configuration file") 

86 else: 

87 secretPath = os.path.expanduser(path) 

88 if not os.path.isfile(secretPath): 

89 raise DbAuthNotFoundError(f"No DbAuth configuration file: {secretPath}") 

90 mode = os.stat(secretPath).st_mode 

91 if mode & (stat.S_IRWXG | stat.S_IRWXO) != 0: 

92 raise DbAuthPermissionsError( 

93 "DbAuth configuration file {} has incorrect permissions: {:o}".format(secretPath, mode) 

94 ) 

95 

96 try: 

97 with open(secretPath) as secretFile: 

98 self.authList = yaml.safe_load(secretFile) 

99 except Exception as exc: 

100 raise DbAuthError(f"Unable to load DbAuth configuration file: {secretPath}.") from exc 

101 

102 # dialectname, hose, and database are tagged as Optional only because other 

103 # routines delegate to this one in order to raise a consistent exception 

104 # for that condition. 

105 def getAuth( 

106 self, 

107 dialectname: Optional[str], 

108 username: Optional[str], 

109 host: Optional[str], 

110 port: Optional[Union[int, str]], 

111 database: Optional[str], 

112 ) -> Tuple[Optional[str], str]: 

113 """Retrieve a username and password for a database connection. 

114 

115 This function matches elements from the database connection URL with 

116 glob-like URL patterns in a list of configuration dictionaries. 

117 

118 Parameters 

119 ---------- 

120 dialectname : `str` 

121 Database dialect, for example sqlite, mysql, postgresql, oracle, 

122 or mssql. 

123 username : `str` or None 

124 Username from connection URL if present. 

125 host : `str` 

126 Host name from connection URL if present. 

127 port : `str` or `int` or None 

128 Port from connection URL if present. 

129 database : `str` 

130 Database name from connection URL. 

131 

132 Returns 

133 ------- 

134 username: `str` 

135 Username to use for database connection; same as parameter if 

136 present. 

137 password: `str` 

138 Password to use for database connection. 

139 

140 Raises 

141 ------ 

142 DbAuthError 

143 Raised if the input is missing elements, an authorization 

144 dictionary is missing elements, the authorization file is 

145 misconfigured, or no matching authorization is found. 

146 

147 Notes 

148 ----- 

149 The list of authorization configuration dictionaries is tested in 

150 order, with the first matching dictionary used. Each dictionary must 

151 contain a ``url`` item with a pattern to match against the database 

152 connection URL and a ``password`` item. If no username is provided in 

153 the database connection URL, the dictionary must also contain a 

154 ``username`` item. 

155 

156 The ``url`` item must begin with a dialect and is not allowed to 

157 specify dialect+driver. 

158 

159 Glob-style patterns (using "``*``" and "``?``" as wildcards) can be 

160 used to match the host and database name portions of the connection 

161 URL. For the username, port, and database name portions, omitting them 

162 from the pattern matches against any value in the connection URL. 

163 

164 Examples 

165 -------- 

166 

167 The connection URL 

168 ``postgresql://user@host.example.com:5432/my_database`` matches against 

169 the identical string as a pattern. Other patterns that would match 

170 include: 

171 

172 * ``postgresql://*`` 

173 * ``postgresql://*.example.com`` 

174 * ``postgresql://*.example.com/my_*`` 

175 * ``postgresql://host.example.com/my_database`` 

176 * ``postgresql://host.example.com:5432/my_database`` 

177 * ``postgresql://user@host.example.com/my_database`` 

178 

179 Note that the connection URL 

180 ``postgresql://host.example.com/my_database`` would not match against 

181 the pattern ``postgresql://host.example.com:5432``, even if the default 

182 port for the connection is 5432. 

183 """ 

184 # Check inputs, squashing MyPy warnings that they're unnecessary 

185 # (since they're only unnecessary if everyone else runs MyPy). 

186 if dialectname is None or dialectname == "": 

187 raise DbAuthError("Missing dialectname parameter") 

188 if host is None or host == "": 

189 raise DbAuthError("Missing host parameter") 

190 if database is None or database == "": 

191 raise DbAuthError("Missing database parameter") 

192 

193 for authDict in self.authList: 

194 

195 # Check for mandatory entries 

196 if "url" not in authDict: 

197 raise DbAuthError("Missing URL in DbAuth configuration") 

198 

199 # Parse pseudo-URL from db-auth.yaml 

200 components = urllib.parse.urlparse(authDict["url"]) 

201 

202 # Check for same database backend type/dialect 

203 if components.scheme == "": 

204 raise DbAuthError("Missing database dialect in URL: " + authDict["url"]) 

205 

206 if "+" in components.scheme: 

207 raise DbAuthError( 

208 "Authorization dictionary URLs should only specify " 

209 f"dialects, got: {components.scheme}. instead." 

210 ) 

211 

212 # dialect and driver are allowed in db string, since functionality 

213 # could change. Connecting to a DB using different driver does not 

214 # change dbname/user/pass and other auth info so we ignore it. 

215 # https://docs.sqlalchemy.org/en/13/core/engines.html#database-urls 

216 dialect = dialectname.split("+")[0] 

217 if dialect != components.scheme: 

218 continue 

219 

220 # Check for same database name 

221 if components.path != "" and components.path != "/": 

222 if not fnmatch.fnmatch(database, components.path.lstrip("/")): 

223 continue 

224 

225 # Check username 

226 if components.username is not None: 

227 if username is None or username == "": 

228 continue 

229 if username != components.username: 

230 continue 

231 

232 # Check hostname 

233 if components.hostname is None: 

234 raise DbAuthError("Missing host in URL: " + authDict["url"]) 

235 if not fnmatch.fnmatch(host, components.hostname): 

236 continue 

237 

238 # Check port 

239 if components.port is not None and (port is None or str(port) != str(components.port)): 

240 continue 

241 

242 # Don't override username from connection string 

243 if username is not None and username != "": 

244 return (username, authDict["password"]) 

245 else: 

246 if "username" not in authDict: 

247 return (None, authDict["password"]) 

248 return (authDict["username"], authDict["password"]) 

249 

250 raise DbAuthNotFoundError( 

251 "No matching DbAuth configuration for: " 

252 f"({dialectname}, {username}, {host}, {port}, {database})" 

253 ) 

254 

255 def getUrl(self, url: str) -> str: 

256 """Fill in a username and password in a database connection URL. 

257 

258 This function parses the URL and calls `getAuth`. 

259 

260 Parameters 

261 ---------- 

262 url : `str` 

263 Database connection URL. 

264 

265 Returns 

266 ------- 

267 url : `str` 

268 Database connection URL with username and password. 

269 

270 Raises 

271 ------ 

272 DbAuthError 

273 Raised if the input is missing elements, an authorization 

274 dictionary is missing elements, the authorization file is 

275 misconfigured, or no matching authorization is found. 

276 

277 See also 

278 -------- 

279 getAuth 

280 """ 

281 components = urllib.parse.urlparse(url) 

282 username, password = self.getAuth( 

283 components.scheme, 

284 components.username, 

285 components.hostname, 

286 components.port, 

287 components.path.lstrip("/"), 

288 ) 

289 hostname = components.hostname 

290 assert hostname is not None 

291 if ":" in hostname: # ipv6 

292 hostname = f"[{hostname}]" 

293 assert username is not None 

294 netloc = "{}:{}@{}".format( 

295 urllib.parse.quote(username, safe=""), urllib.parse.quote(password, safe=""), hostname 

296 ) 

297 if components.port is not None: 

298 netloc += ":" + str(components.port) 

299 return urllib.parse.urlunparse( 

300 ( 

301 components.scheme, 

302 netloc, 

303 components.path, 

304 components.params, 

305 components.query, 

306 components.fragment, 

307 ) 

308 )