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/>. 

21 

22from __future__ import annotations 

23 

24import fnmatch 

25import os 

26import stat 

27import urllib.parse 

28 

29import yaml 

30 

31__all__ = ["DbAuth", "DbAuthError", "DbAuthPermissionsError"] 

32 

33 

34class DbAuthError(RuntimeError): 

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

36 authentication information. 

37 """ 

38 

39 pass 

40 

41 

42class DbAuthNotFoundError(DbAuthError): 

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

44 

45 

46class DbAuthPermissionsError(DbAuthError): 

47 """Credentials file has incorrect permissions.""" 

48 

49 

50class DbAuth: 

51 """Retrieves authentication information for database connections. 

52 

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

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

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

56 

57 Parameters 

58 ---------- 

59 path : `str` or None, optional 

60 Path to configuration file. 

61 envVar : `str` or None, optional 

62 Name of environment variable pointing to configuration file. 

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

64 Authentication configuration. 

65 

66 Notes 

67 ----- 

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

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

70 """ 

71 

72 def __init__( 

73 self, 

74 path: str | None = None, 

75 envVar: str | None = None, 

76 authList: list[dict[str, str]] | None = None, 

77 ): 

78 if authList is not None: 

79 self.authList = authList 

80 return 

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

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

83 elif path is None: 

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

85 else: 

86 secretPath = os.path.expanduser(path) 

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

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

89 mode = os.stat(secretPath).st_mode 

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

91 raise DbAuthPermissionsError( 

92 f"DbAuth configuration file {secretPath} has incorrect permissions: {mode:o}" 

93 ) 

94 

95 try: 

96 with open(secretPath) as secretFile: 

97 self.authList = yaml.safe_load(secretFile) 

98 except Exception as exc: 

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

100 

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

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

103 # for that condition. 

104 def getAuth( 

105 self, 

106 dialectname: str | None, 

107 username: str | None, 

108 host: str | None, 

109 port: int | str | None, 

110 database: str | None, 

111 ) -> tuple[str | None, str]: 

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

113 

114 This function matches elements from the database connection URL with 

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

116 

117 Parameters 

118 ---------- 

119 dialectname : `str` 

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

121 or mssql. 

122 username : `str` or None 

123 Username from connection URL if present. 

124 host : `str` 

125 Host name from connection URL if present. 

126 port : `str` or `int` or None 

127 Port from connection URL if present. 

128 database : `str` 

129 Database name from connection URL. 

130 

131 Returns 

132 ------- 

133 username: `str` 

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

135 present. 

136 password: `str` 

137 Password to use for database connection. 

138 

139 Raises 

140 ------ 

141 DbAuthError 

142 Raised if the input is missing elements, an authorization 

143 dictionary is missing elements, the authorization file is 

144 misconfigured, or no matching authorization is found. 

145 

146 Notes 

147 ----- 

148 The list of authorization configuration dictionaries is tested in 

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

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

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

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

153 ``username`` item. 

154 

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

156 specify dialect+driver. 

157 

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

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

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

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

162 

163 Examples 

164 -------- 

165 

166 The connection URL 

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

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

169 include: 

170 

171 * ``postgresql://*`` 

172 * ``postgresql://*.example.com`` 

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

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

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

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

177 

178 Note that the connection URL 

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

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

181 port for the connection is 5432. 

182 """ 

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

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

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

186 raise DbAuthError("Missing dialectname parameter") 

187 if host is None or host == "": 

188 raise DbAuthError("Missing host parameter") 

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

190 raise DbAuthError("Missing database parameter") 

191 

192 for authDict in self.authList: 

193 # Check for mandatory entries 

194 if "url" not in authDict: 

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

196 

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

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

199 

200 # Check for same database backend type/dialect 

201 if components.scheme == "": 

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

203 

204 if "+" in components.scheme: 

205 raise DbAuthError( 

206 "Authorization dictionary URLs should only specify " 

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

208 ) 

209 

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

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

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

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

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

215 if dialect != components.scheme: 

216 continue 

217 

218 # Check for same database name 

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

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

221 continue 

222 

223 # Check username 

224 if components.username is not None: 

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

226 continue 

227 if username != components.username: 

228 continue 

229 

230 # Check hostname 

231 if components.hostname is None: 

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

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

234 continue 

235 

236 # Check port 

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

238 continue 

239 

240 # Don't override username from connection string 

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

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

243 else: 

244 if "username" not in authDict: 

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

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

247 

248 raise DbAuthNotFoundError( 

249 f"No matching DbAuth configuration for: ({dialectname}, {username}, {host}, {port}, {database})" 

250 ) 

251 

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

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

254 

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

256 

257 Parameters 

258 ---------- 

259 url : `str` 

260 Database connection URL. 

261 

262 Returns 

263 ------- 

264 url : `str` 

265 Database connection URL with username and password. 

266 

267 Raises 

268 ------ 

269 DbAuthError 

270 Raised if the input is missing elements, an authorization 

271 dictionary is missing elements, the authorization file is 

272 misconfigured, or no matching authorization is found. 

273 

274 See also 

275 -------- 

276 getAuth 

277 """ 

278 components = urllib.parse.urlparse(url) 

279 username, password = self.getAuth( 

280 components.scheme, 

281 components.username, 

282 components.hostname, 

283 components.port, 

284 components.path.lstrip("/"), 

285 ) 

286 hostname = components.hostname 

287 assert hostname is not None 

288 if ":" in hostname: # ipv6 

289 hostname = f"[{hostname}]" 

290 assert username is not None 

291 netloc = "{}:{}@{}".format( 

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

293 ) 

294 if components.port is not None: 

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

296 return urllib.parse.urlunparse( 

297 ( 

298 components.scheme, 

299 netloc, 

300 components.path, 

301 components.params, 

302 components.query, 

303 components.fragment, 

304 ) 

305 )