includes/installer/PostgresInstaller.php

   1 <?php
   2 /**
   3  * PostgreSQL-specific installer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Deployment
  22  */
  23
  24 use Wikimedia\Rdbms\Database;
  25 use Wikimedia\Rdbms\DatabasePostgres;
  26 use Wikimedia\Rdbms\DBQueryError;
  27 use Wikimedia\Rdbms\DBConnectionError;
  28
  29 /**
  30  * Class for setting up the MediaWiki database using Postgres.
  31  *
  32  * @ingroup Deployment
  33  * @since 1.17
  34  */
  35 class PostgresInstaller extends DatabaseInstaller {
  36
  37         protected $globalNames = [
  38                 'wgDBserver',
  39                 'wgDBport',
  40                 'wgDBname',
  41                 'wgDBuser',
  42                 'wgDBpassword',
  43                 'wgDBmwschema',
  44         ];
  45
  46         protected $internalDefaults = [
  47                 '_InstallUser' => 'postgres',
  48         ];
  49
  50         public static $minimumVersion = '9.2';
  51         protected static $notMinimumVersionMessage = 'config-postgres-old';
  52         public $maxRoleSearchDepth = 5;
  53
  54         protected $pgConns = [];
  55
  56         function getName() {
  57                 return 'postgres';
  58         }
  59
  60         public function isCompiled() {
  61                 return self::checkExtension( 'pgsql' );
  62         }
  63
  64         function getConnectForm() {
  65                 return $this->getTextBox(
  66                         'wgDBserver',
  67                         'config-db-host',
  68                         [],
  69                         $this->parent->getHelpBox( 'config-db-host-help' )
  70                 ) .
  71                         $this->getTextBox( 'wgDBport', 'config-db-port' ) .
  72                         Html::openElement( 'fieldset' ) .
  73                         Html::element( 'legend', [], wfMessage( 'config-db-wiki-settings' )->text() ) .
  74                         $this->getTextBox(
  75                                 'wgDBname',
  76                                 'config-db-name',
  77                                 [],
  78                                 $this->parent->getHelpBox( 'config-db-name-help' )
  79                         ) .
  80                         $this->getTextBox(
  81                                 'wgDBmwschema',
  82                                 'config-db-schema',
  83                                 [],
  84                                 $this->parent->getHelpBox( 'config-db-schema-help' )
  85                         ) .
  86                         Html::closeElement( 'fieldset' ) .
  87                         $this->getInstallUserBox();
  88         }
  89
  90         function submitConnectForm() {
  91                 // Get variables from the request
  92                 $newValues = $this->setVarsFromRequest( [
  93                         'wgDBserver',
  94                         'wgDBport',
  95                         'wgDBname',
  96                         'wgDBmwschema'
  97                 ] );
  98
  99                 // Validate them
 100                 $status = Status::newGood();
 101                 if ( !strlen( $newValues['wgDBname'] ) ) {
 102                         $status->fatal( 'config-missing-db-name' );
 103                 } elseif ( !preg_match( '/^[a-zA-Z0-9_]+$/', $newValues['wgDBname'] ) ) {
 104                         $status->fatal( 'config-invalid-db-name', $newValues['wgDBname'] );
 105                 }
 106                 if ( !preg_match( '/^[a-zA-Z0-9_]*$/', $newValues['wgDBmwschema'] ) ) {
 107                         $status->fatal( 'config-invalid-schema', $newValues['wgDBmwschema'] );
 108                 }
 109
 110                 // Submit user box
 111                 if ( $status->isOK() ) {
 112                         $status->merge( $this->submitInstallUserBox() );
 113                 }
 114                 if ( !$status->isOK() ) {
 115                         return $status;
 116                 }
 117
 118                 $status = $this->getPgConnection( 'create-db' );
 119                 if ( !$status->isOK() ) {
 120                         return $status;
 121                 }
 122                 /**
 123                  * @var Database $conn
 124                  */
 125                 $conn = $status->value;
 126
 127                 // Check version
 128                 $version = $conn->getServerVersion();
 129                 $status = static::meetsMinimumRequirement( $version );
 130                 if ( !$status->isOK() ) {
 131                         return $status;
 132                 }
 133
 134                 $this->setVar( 'wgDBuser', $this->getVar( '_InstallUser' ) );
 135                 $this->setVar( 'wgDBpassword', $this->getVar( '_InstallPassword' ) );
 136
 137                 return Status::newGood();
 138         }
 139
 140         public function getConnection() {
 141                 $status = $this->getPgConnection( 'create-tables' );
 142                 if ( $status->isOK() ) {
 143                         $this->db = $status->value;
 144                 }
 145
 146                 return $status;
 147         }
 148
 149         public function openConnection() {
 150                 return $this->openPgConnection( 'create-tables' );
 151         }
 152
 153         /**
 154          * Open a PG connection with given parameters
 155          * @param string $user User name
 156          * @param string $password
 157          * @param string $dbName Database name
 158          * @param string $schema Database schema
 159          * @return Status
 160          */
 161         protected function openConnectionWithParams( $user, $password, $dbName, $schema ) {
 162                 $status = Status::newGood();
 163                 try {
 164                         $db = Database::factory( 'postgres', [
 165                                 'host' => $this->getVar( 'wgDBserver' ),
 166                                 'port' => $this->getVar( 'wgDBport' ),
 167                                 'user' => $user,
 168                                 'password' => $password,
 169                                 'dbname' => $dbName,
 170                                 'schema' => $schema,
 171                                 'keywordTableMap' => [ 'user' => 'mwuser', 'text' => 'pagecontent' ],
 172                         ] );
 173                         $status->value = $db;
 174                 } catch ( DBConnectionError $e ) {
 175                         $status->fatal( 'config-connection-error', $e->getMessage() );
 176                 }
 177
 178                 return $status;
 179         }
 180
 181         /**
 182          * Get a special type of connection
 183          * @param string $type See openPgConnection() for details.
 184          * @return Status
 185          */
 186         protected function getPgConnection( $type ) {
 187                 if ( isset( $this->pgConns[$type] ) ) {
 188                         return Status::newGood( $this->pgConns[$type] );
 189                 }
 190                 $status = $this->openPgConnection( $type );
 191
 192                 if ( $status->isOK() ) {
 193                         /**
 194                          * @var Database $conn
 195                          */
 196                         $conn = $status->value;
 197                         $conn->clearFlag( DBO_TRX );
 198                         $conn->commit( __METHOD__ );
 199                         $this->pgConns[$type] = $conn;
 200                 }
 201
 202                 return $status;
 203         }
 204
 205         /**
 206          * Get a connection of a specific PostgreSQL-specific type. Connections
 207          * of a given type are cached.
 208          *
 209          * PostgreSQL lacks cross-database operations, so after the new database is
 210          * created, you need to make a separate connection to connect to that
 211          * database and add tables to it.
 212          *
 213          * New tables are owned by the user that creates them, and MediaWiki's
 214          * PostgreSQL support has always assumed that the table owner will be
 215          * $wgDBuser. So before we create new tables, we either need to either
 216          * connect as the other user or to execute a SET ROLE command. Using a
 217          * separate connection for this allows us to avoid accidental cross-module
 218          * dependencies.
 219          *
 220          * @param string $type The type of connection to get:
 221          *    - create-db:     A connection for creating DBs, suitable for pre-
 222          *                     installation.
 223          *    - create-schema: A connection to the new DB, for creating schemas and
 224          *                     other similar objects in the new DB.
 225          *    - create-tables: A connection with a role suitable for creating tables.
 226          *
 227          * @throws MWException
 228          * @return Status On success, a connection object will be in the value member.
 229          */
 230         protected function openPgConnection( $type ) {
 231                 switch ( $type ) {
 232                         case 'create-db':
 233                                 return $this->openConnectionToAnyDB(
 234                                         $this->getVar( '_InstallUser' ),
 235                                         $this->getVar( '_InstallPassword' ) );
 236                         case 'create-schema':
 237                                 return $this->openConnectionWithParams(
 238                                         $this->getVar( '_InstallUser' ),
 239                                         $this->getVar( '_InstallPassword' ),
 240                                         $this->getVar( 'wgDBname' ),
 241                                         $this->getVar( 'wgDBmwschema' ) );
 242                         case 'create-tables':
 243                                 $status = $this->openPgConnection( 'create-schema' );
 244                                 if ( $status->isOK() ) {
 245                                         /**
 246                                          * @var Database $conn
 247                                          */
 248                                         $conn = $status->value;
 249                                         $safeRole = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
 250                                         $conn->query( "SET ROLE $safeRole" );
 251                                 }
 252
 253                                 return $status;
 254                         default:
 255                                 throw new MWException( "Invalid special connection type: \"$type\"" );
 256                 }
 257         }
 258
 259         public function openConnectionToAnyDB( $user, $password ) {
 260                 $dbs = [
 261                         'template1',
 262                         'postgres',
 263                 ];
 264                 if ( !in_array( $this->getVar( 'wgDBname' ), $dbs ) ) {
 265                         array_unshift( $dbs, $this->getVar( 'wgDBname' ) );
 266                 }
 267                 $conn = false;
 268                 $status = Status::newGood();
 269                 foreach ( $dbs as $db ) {
 270                         try {
 271                                 $p = [
 272                                         'host' => $this->getVar( 'wgDBserver' ),
 273                                         'user' => $user,
 274                                         'password' => $password,
 275                                         'dbname' => $db
 276                                 ];
 277                                 $conn = Database::factory( 'postgres', $p );
 278                         } catch ( DBConnectionError $error ) {
 279                                 $conn = false;
 280                                 $status->fatal( 'config-pg-test-error', $db,
 281                                         $error->getMessage() );
 282                         }
 283                         if ( $conn !== false ) {
 284                                 break;
 285                         }
 286                 }
 287                 if ( $conn !== false ) {
 288                         return Status::newGood( $conn );
 289                 } else {
 290                         return $status;
 291                 }
 292         }
 293
 294         protected function getInstallUserPermissions() {
 295                 $status = $this->getPgConnection( 'create-db' );
 296                 if ( !$status->isOK() ) {
 297                         return false;
 298                 }
 299                 /**
 300                  * @var Database $conn
 301                  */
 302                 $conn = $status->value;
 303                 $superuser = $this->getVar( '_InstallUser' );
 304
 305                 $row = $conn->selectRow( '"pg_catalog"."pg_roles"', '*',
 306                         [ 'rolname' => $superuser ], __METHOD__ );
 307
 308                 return $row;
 309         }
 310
 311         protected function canCreateAccounts() {
 312                 $perms = $this->getInstallUserPermissions();
 313                 if ( !$perms ) {
 314                         return false;
 315                 }
 316
 317                 return $perms->rolsuper === 't' || $perms->rolcreaterole === 't';
 318         }
 319
 320         protected function isSuperUser() {
 321                 $perms = $this->getInstallUserPermissions();
 322                 if ( !$perms ) {
 323                         return false;
 324                 }
 325
 326                 return $perms->rolsuper === 't';
 327         }
 328
 329         public function getSettingsForm() {
 330                 if ( $this->canCreateAccounts() ) {
 331                         $noCreateMsg = false;
 332                 } else {
 333                         $noCreateMsg = 'config-db-web-no-create-privs';
 334                 }
 335                 $s = $this->getWebUserBox( $noCreateMsg );
 336
 337                 return $s;
 338         }
 339
 340         public function submitSettingsForm() {
 341                 $status = $this->submitWebUserBox();
 342                 if ( !$status->isOK() ) {
 343                         return $status;
 344                 }
 345
 346                 $same = $this->getVar( 'wgDBuser' ) === $this->getVar( '_InstallUser' );
 347
 348                 if ( $same ) {
 349                         $exists = true;
 350                 } else {
 351                         // Check if the web user exists
 352                         // Connect to the database with the install user
 353                         $status = $this->getPgConnection( 'create-db' );
 354                         if ( !$status->isOK() ) {
 355                                 return $status;
 356                         }
 357                         // @phan-suppress-next-line PhanUndeclaredMethod
 358                         $exists = $status->value->roleExists( $this->getVar( 'wgDBuser' ) );
 359                 }
 360
 361                 // Validate the create checkbox
 362                 if ( $this->canCreateAccounts() && !$same && !$exists ) {
 363                         $create = $this->getVar( '_CreateDBAccount' );
 364                 } else {
 365                         $this->setVar( '_CreateDBAccount', false );
 366                         $create = false;
 367                 }
 368
 369                 if ( !$create && !$exists ) {
 370                         if ( $this->canCreateAccounts() ) {
 371                                 $msg = 'config-install-user-missing-create';
 372                         } else {
 373                                 $msg = 'config-install-user-missing';
 374                         }
 375
 376                         return Status::newFatal( $msg, $this->getVar( 'wgDBuser' ) );
 377                 }
 378
 379                 if ( !$exists ) {
 380                         // No more checks to do
 381                         return Status::newGood();
 382                 }
 383
 384                 // Existing web account. Test the connection.
 385                 $status = $this->openConnectionToAnyDB(
 386                         $this->getVar( 'wgDBuser' ),
 387                         $this->getVar( 'wgDBpassword' ) );
 388                 if ( !$status->isOK() ) {
 389                         return $status;
 390                 }
 391
 392                 // The web user is conventionally the table owner in PostgreSQL
 393                 // installations. Make sure the install user is able to create
 394                 // objects on behalf of the web user.
 395                 if ( $same || $this->canCreateObjectsForWebUser() ) {
 396                         return Status::newGood();
 397                 } else {
 398                         return Status::newFatal( 'config-pg-not-in-role' );
 399                 }
 400         }
 401
 402         /**
 403          * Returns true if the install user is able to create objects owned
 404          * by the web user, false otherwise.
 405          * @return bool
 406          */
 407         protected function canCreateObjectsForWebUser() {
 408                 if ( $this->isSuperUser() ) {
 409                         return true;
 410                 }
 411
 412                 $status = $this->getPgConnection( 'create-db' );
 413                 if ( !$status->isOK() ) {
 414                         return false;
 415                 }
 416                 $conn = $status->value;
 417                 $installerId = $conn->selectField( '"pg_catalog"."pg_roles"', 'oid',
 418                         [ 'rolname' => $this->getVar( '_InstallUser' ) ], __METHOD__ );
 419                 $webId = $conn->selectField( '"pg_catalog"."pg_roles"', 'oid',
 420                         [ 'rolname' => $this->getVar( 'wgDBuser' ) ], __METHOD__ );
 421
 422                 return $this->isRoleMember( $conn, $installerId, $webId, $this->maxRoleSearchDepth );
 423         }
 424
 425         /**
 426          * Recursive helper for canCreateObjectsForWebUser().
 427          * @param Database $conn
 428          * @param int $targetMember Role ID of the member to look for
 429          * @param int $group Role ID of the group to look for
 430          * @param int $maxDepth Maximum recursive search depth
 431          * @return bool
 432          */
 433         protected function isRoleMember( $conn, $targetMember, $group, $maxDepth ) {
 434                 if ( $targetMember === $group ) {
 435                         // A role is always a member of itself
 436                         return true;
 437                 }
 438                 // Get all members of the given group
 439                 $res = $conn->select( '"pg_catalog"."pg_auth_members"', [ 'member' ],
 440                         [ 'roleid' => $group ], __METHOD__ );
 441                 foreach ( $res as $row ) {
 442                         if ( $row->member == $targetMember ) {
 443                                 // Found target member
 444                                 return true;
 445                         }
 446                         // Recursively search each member of the group to see if the target
 447                         // is a member of it, up to the given maximum depth.
 448                         if ( $maxDepth > 0 &&
 449                                 $this->isRoleMember( $conn, $targetMember, $row->member, $maxDepth - 1 )
 450                         ) {
 451                                 // Found member of member
 452                                 return true;
 453                         }
 454                 }
 455
 456                 return false;
 457         }
 458
 459         public function preInstall() {
 460                 $createDbAccount = [
 461                         'name' => 'user',
 462                         'callback' => [ $this, 'setupUser' ],
 463                 ];
 464                 $commitCB = [
 465                         'name' => 'pg-commit',
 466                         'callback' => [ $this, 'commitChanges' ],
 467                 ];
 468                 $plpgCB = [
 469                         'name' => 'pg-plpgsql',
 470                         'callback' => [ $this, 'setupPLpgSQL' ],
 471                 ];
 472                 $schemaCB = [
 473                         'name' => 'schema',
 474                         'callback' => [ $this, 'setupSchema' ]
 475                 ];
 476
 477                 if ( $this->getVar( '_CreateDBAccount' ) ) {
 478                         $this->parent->addInstallStep( $createDbAccount, 'database' );
 479                 }
 480                 $this->parent->addInstallStep( $commitCB, 'interwiki' );
 481                 $this->parent->addInstallStep( $plpgCB, 'database' );
 482                 $this->parent->addInstallStep( $schemaCB, 'database' );
 483         }
 484
 485         function setupDatabase() {
 486                 $status = $this->getPgConnection( 'create-db' );
 487                 if ( !$status->isOK() ) {
 488                         return $status;
 489                 }
 490                 $conn = $status->value;
 491
 492                 $dbName = $this->getVar( 'wgDBname' );
 493
 494                 $exists = $conn->selectField( '"pg_catalog"."pg_database"', '1',
 495                         [ 'datname' => $dbName ], __METHOD__ );
 496                 if ( !$exists ) {
 497                         $safedb = $conn->addIdentifierQuotes( $dbName );
 498                         $conn->query( "CREATE DATABASE $safedb", __METHOD__ );
 499                 }
 500
 501                 return Status::newGood();
 502         }
 503
 504         function setupSchema() {
 505                 // Get a connection to the target database
 506                 $status = $this->getPgConnection( 'create-schema' );
 507                 if ( !$status->isOK() ) {
 508                         return $status;
 509                 }
 510                 /** @var DatabasePostgres $conn */
 511                 $conn = $status->value;
 512                 '@phan-var DatabasePostgres $conn';
 513
 514                 // Create the schema if necessary
 515                 $schema = $this->getVar( 'wgDBmwschema' );
 516                 $safeschema = $conn->addIdentifierQuotes( $schema );
 517                 $safeuser = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
 518                 if ( !$conn->schemaExists( $schema ) ) {
 519                         try {
 520                                 $conn->query( "CREATE SCHEMA $safeschema AUTHORIZATION $safeuser" );
 521                         } catch ( DBQueryError $e ) {
 522                                 return Status::newFatal( 'config-install-pg-schema-failed',
 523                                         $this->getVar( '_InstallUser' ), $schema );
 524                         }
 525                 }
 526
 527                 // Select the new schema in the current connection
 528                 $conn->determineCoreSchema( $schema );
 529
 530                 return Status::newGood();
 531         }
 532
 533         function commitChanges() {
 534                 $this->db->commit( __METHOD__ );
 535
 536                 return Status::newGood();
 537         }
 538
 539         function setupUser() {
 540                 if ( !$this->getVar( '_CreateDBAccount' ) ) {
 541                         return Status::newGood();
 542                 }
 543
 544                 $status = $this->getPgConnection( 'create-db' );
 545                 if ( !$status->isOK() ) {
 546                         return $status;
 547                 }
 548                 /** @var DatabasePostgres $conn */
 549                 $conn = $status->value;
 550                 '@phan-var DatabasePostgres $conn';
 551
 552                 $safeuser = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
 553                 $safepass = $conn->addQuotes( $this->getVar( 'wgDBpassword' ) );
 554
 555                 // Check if the user already exists
 556                 $userExists = $conn->roleExists( $this->getVar( 'wgDBuser' ) );
 557                 if ( !$userExists ) {
 558                         // Create the user
 559                         try {
 560                                 $sql = "CREATE ROLE $safeuser NOCREATEDB LOGIN PASSWORD $safepass";
 561
 562                                 // If the install user is not a superuser, we need to make the install
 563                                 // user a member of the new user's group, so that the install user will
 564                                 // be able to create a schema and other objects on behalf of the new user.
 565                                 if ( !$this->isSuperUser() ) {
 566                                         $sql .= ' ROLE' . $conn->addIdentifierQuotes( $this->getVar( '_InstallUser' ) );
 567                                 }
 568
 569                                 $conn->query( $sql, __METHOD__ );
 570                         } catch ( DBQueryError $e ) {
 571                                 return Status::newFatal( 'config-install-user-create-failed',
 572                                         $this->getVar( 'wgDBuser' ), $e->getMessage() );
 573                         }
 574                 }
 575
 576                 return Status::newGood();
 577         }
 578
 579         function getLocalSettings() {
 580                 $port = $this->getVar( 'wgDBport' );
 581                 $schema = $this->getVar( 'wgDBmwschema' );
 582
 583                 return "# Postgres specific settings
 584 \$wgDBport = \"{$port}\";
 585 \$wgDBmwschema = \"{$schema}\";";
 586         }
 587
 588         public function preUpgrade() {
 589                 global $wgDBuser, $wgDBpassword;
 590
 591                 # Normal user and password are selected after this step, so for now
 592                 # just copy these two
 593                 $wgDBuser = $this->getVar( '_InstallUser' );
 594                 $wgDBpassword = $this->getVar( '_InstallPassword' );
 595         }
 596
 597         public function createTables() {
 598                 $schema = $this->getVar( 'wgDBmwschema' );
 599
 600                 $status = $this->getConnection();
 601                 if ( !$status->isOK() ) {
 602                         return $status;
 603                 }
 604
 605                 /** @var DatabasePostgres $conn */
 606                 $conn = $status->value;
 607                 '@phan-var DatabasePostgres $conn';
 608
 609                 if ( $conn->tableExists( 'archive' ) ) {
 610                         $status->warning( 'config-install-tables-exist' );
 611                         $this->enableLB();
 612
 613                         return $status;
 614                 }
 615
 616                 $conn->begin( __METHOD__ );
 617
 618                 if ( !$conn->schemaExists( $schema ) ) {
 619                         $status->fatal( 'config-install-pg-schema-not-exist' );
 620
 621                         return $status;
 622                 }
 623                 $error = $conn->sourceFile( $this->getSchemaPath( $conn ) );
 624                 if ( $error !== true ) {
 625                         $conn->reportQueryError( $error, 0, '', __METHOD__ );
 626                         $conn->rollback( __METHOD__ );
 627                         $status->fatal( 'config-install-tables-failed', $error );
 628                 } else {
 629                         $conn->commit( __METHOD__ );
 630                 }
 631                 // Resume normal operations
 632                 if ( $status->isOK() ) {
 633                         $this->enableLB();
 634                 }
 635
 636                 return $status;
 637         }
 638
 639         public function getGlobalDefaults() {
 640                 // The default $wgDBmwschema is null, which breaks Postgres and other DBMSes that require
 641                 // the use of a schema, so we need to set it here
 642                 return array_merge( parent::getGlobalDefaults(), [
 643                         'wgDBmwschema' => 'mediawiki',
 644                 ] );
 645         }
 646
 647         public function setupPLpgSQL() {
 648                 // Connect as the install user, since it owns the database and so is
 649                 // the user that needs to run "CREATE LANGUAGE"
 650                 $status = $this->getPgConnection( 'create-schema' );
 651                 if ( !$status->isOK() ) {
 652                         return $status;
 653                 }
 654                 /**
 655                  * @var Database $conn
 656                  */
 657                 $conn = $status->value;
 658
 659                 $exists = $conn->selectField( '"pg_catalog"."pg_language"', 1,
 660                         [ 'lanname' => 'plpgsql' ], __METHOD__ );
 661                 if ( $exists ) {
 662                         // Already exists, nothing to do
 663                         return Status::newGood();
 664                 }
 665
 666                 // plpgsql is not installed, but if we have a pg_pltemplate table, we
 667                 // should be able to create it
 668                 $exists = $conn->selectField(
 669                         [ '"pg_catalog"."pg_class"', '"pg_catalog"."pg_namespace"' ],
 670                         1,
 671                         [
 672                                 'pg_namespace.oid=relnamespace',
 673                                 'nspname' => 'pg_catalog',
 674                                 'relname' => 'pg_pltemplate',
 675                         ],
 676                         __METHOD__ );
 677                 if ( $exists ) {
 678                         try {
 679                                 $conn->query( 'CREATE LANGUAGE plpgsql' );
 680                         } catch ( DBQueryError $e ) {
 681                                 return Status::newFatal( 'config-pg-no-plpgsql', $this->getVar( 'wgDBname' ) );
 682                         }
 683                 } else {
 684                         return Status::newFatal( 'config-pg-no-plpgsql', $this->getVar( 'wgDBname' ) );
 685                 }
 686
 687                 return Status::newGood();
 688         }
 689 }