rdbms: Avoid selectDB() call in LoadMonitor new connections

[mediawiki.git] / includes / installer / PostgresInstaller.php

<?php
/**
 * PostgreSQL-specific installer.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Deployment
 */

use Wikimedia\Rdbms\Database;
use Wikimedia\Rdbms\DBQueryError;
use Wikimedia\Rdbms\DBConnectionError;

/**
 * Class for setting up the MediaWiki database using Postgres.
 *
 * @ingroup Deployment
 * @since 1.17
 */
class PostgresInstaller extends DatabaseInstaller {

        protected $globalNames = [
                'wgDBserver',
                'wgDBport',
                'wgDBname',
                'wgDBuser',
                'wgDBpassword',
                'wgDBmwschema',
        ];

        protected $internalDefaults = [
                '_InstallUser' => 'postgres',
        ];

        public $minimumVersion = '8.3';
        public $maxRoleSearchDepth = 5;

        protected $pgConns = [];

        function getName() {
                return 'postgres';
        }

        public function isCompiled() {
                return self::checkExtension( 'pgsql' );
        }

        function getConnectForm() {
                return $this->getTextBox(
                        'wgDBserver',
                        'config-db-host',
                        [],
                        $this->parent->getHelpBox( 'config-db-host-help' )
                ) .
                        $this->getTextBox( 'wgDBport', 'config-db-port' ) .
                        Html::openElement( 'fieldset' ) .
                        Html::element( 'legend', [], wfMessage( 'config-db-wiki-settings' )->text() ) .
                        $this->getTextBox(
                                'wgDBname',
                                'config-db-name',
                                [],
                                $this->parent->getHelpBox( 'config-db-name-help' )
                        ) .
                        $this->getTextBox(
                                'wgDBmwschema',
                                'config-db-schema',
                                [],
                                $this->parent->getHelpBox( 'config-db-schema-help' )
                        ) .
                        Html::closeElement( 'fieldset' ) .
                        $this->getInstallUserBox();
        }

        function submitConnectForm() {
                // Get variables from the request
                $newValues = $this->setVarsFromRequest( [
                        'wgDBserver',
                        'wgDBport',
                        'wgDBname',
                        'wgDBmwschema'
                ] );

                // Validate them
                $status = Status::newGood();
                if ( !strlen( $newValues['wgDBname'] ) ) {
                        $status->fatal( 'config-missing-db-name' );
                } elseif ( !preg_match( '/^[a-zA-Z0-9_]+$/', $newValues['wgDBname'] ) ) {
                        $status->fatal( 'config-invalid-db-name', $newValues['wgDBname'] );
                }
                if ( !preg_match( '/^[a-zA-Z0-9_]*$/', $newValues['wgDBmwschema'] ) ) {
                        $status->fatal( 'config-invalid-schema', $newValues['wgDBmwschema'] );
                }

                // Submit user box
                if ( $status->isOK() ) {
                        $status->merge( $this->submitInstallUserBox() );
                }
                if ( !$status->isOK() ) {
                        return $status;
                }

                $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return $status;
                }
                /**
                 * @var $conn Database
                 */
                $conn = $status->value;

                // Check version
                $version = $conn->getServerVersion();
                if ( version_compare( $version, $this->minimumVersion ) < 0 ) {
                        return Status::newFatal( 'config-postgres-old', $this->minimumVersion, $version );
                }

                $this->setVar( 'wgDBuser', $this->getVar( '_InstallUser' ) );
                $this->setVar( 'wgDBpassword', $this->getVar( '_InstallPassword' ) );

                return Status::newGood();
        }

        public function getConnection() {
                $status = $this->getPgConnection( 'create-tables' );
                if ( $status->isOK() ) {
                        $this->db = $status->value;
                }

                return $status;
        }

        public function openConnection() {
                return $this->openPgConnection( 'create-tables' );
        }

        /**
         * Open a PG connection with given parameters
         * @param string $user User name
         * @param string $password Password
         * @param string $dbName Database name
         * @param string $schema Database schema
         * @return Status
         */
        protected function openConnectionWithParams( $user, $password, $dbName, $schema ) {
                $status = Status::newGood();
                try {
                        $db = Database::factory( 'postgres', [
                                'host' => $this->getVar( 'wgDBserver' ),
                                'port' => $this->getVar( 'wgDBport' ),
                                'user' => $user,
                                'password' => $password,
                                'dbname' => $dbName,
                                'schema' => $schema,
                                'keywordTableMap' => [ 'user' => 'mwuser', 'text' => 'pagecontent' ],
                        ] );
                        $status->value = $db;
                } catch ( DBConnectionError $e ) {
                        $status->fatal( 'config-connection-error', $e->getMessage() );
                }

                return $status;
        }

        /**
         * Get a special type of connection
         * @param string $type See openPgConnection() for details.
         * @return Status
         */
        protected function getPgConnection( $type ) {
                if ( isset( $this->pgConns[$type] ) ) {
                        return Status::newGood( $this->pgConns[$type] );
                }
                $status = $this->openPgConnection( $type );

                if ( $status->isOK() ) {
                        /**
                         * @var $conn Database
                         */
                        $conn = $status->value;
                        $conn->clearFlag( DBO_TRX );
                        $conn->commit( __METHOD__ );
                        $this->pgConns[$type] = $conn;
                }

                return $status;
        }

        /**
         * Get a connection of a specific PostgreSQL-specific type. Connections
         * of a given type are cached.
         *
         * PostgreSQL lacks cross-database operations, so after the new database is
         * created, you need to make a separate connection to connect to that
         * database and add tables to it.
         *
         * New tables are owned by the user that creates them, and MediaWiki's
         * PostgreSQL support has always assumed that the table owner will be
         * $wgDBuser. So before we create new tables, we either need to either
         * connect as the other user or to execute a SET ROLE command. Using a
         * separate connection for this allows us to avoid accidental cross-module
         * dependencies.
         *
         * @param string $type The type of connection to get:
         *    - create-db:     A connection for creating DBs, suitable for pre-
         *                     installation.
         *    - create-schema: A connection to the new DB, for creating schemas and
         *                     other similar objects in the new DB.
         *    - create-tables: A connection with a role suitable for creating tables.
         *
         * @throws MWException
         * @return Status On success, a connection object will be in the value member.
         */
        protected function openPgConnection( $type ) {
                switch ( $type ) {
                        case 'create-db':
                                return $this->openConnectionToAnyDB(
                                        $this->getVar( '_InstallUser' ),
                                        $this->getVar( '_InstallPassword' ) );
                        case 'create-schema':
                                return $this->openConnectionWithParams(
                                        $this->getVar( '_InstallUser' ),
                                        $this->getVar( '_InstallPassword' ),
                                        $this->getVar( 'wgDBname' ),
                                        $this->getVar( 'wgDBmwschema' ) );
                        case 'create-tables':
                                $status = $this->openPgConnection( 'create-schema' );
                                if ( $status->isOK() ) {
                                        /**
                                         * @var $conn Database
                                         */
                                        $conn = $status->value;
                                        $safeRole = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
                                        $conn->query( "SET ROLE $safeRole" );
                                }

                                return $status;
                        default:
                                throw new MWException( "Invalid special connection type: \"$type\"" );
                }
        }

        public function openConnectionToAnyDB( $user, $password ) {
                $dbs = [
                        'template1',
                        'postgres',
                ];
                if ( !in_array( $this->getVar( 'wgDBname' ), $dbs ) ) {
                        array_unshift( $dbs, $this->getVar( 'wgDBname' ) );
                }
                $conn = false;
                $status = Status::newGood();
                foreach ( $dbs as $db ) {
                        try {
                                $p = [
                                        'host' => $this->getVar( 'wgDBserver' ),
                                        'user' => $user,
                                        'password' => $password,
                                        'dbname' => $db
                                ];
                                $conn = Database::factory( 'postgres', $p );
                        } catch ( DBConnectionError $error ) {
                                $conn = false;
                                $status->fatal( 'config-pg-test-error', $db,
                                        $error->getMessage() );
                        }
                        if ( $conn !== false ) {
                                break;
                        }
                }
                if ( $conn !== false ) {
                        return Status::newGood( $conn );
                } else {
                        return $status;
                }
        }

        protected function getInstallUserPermissions() {
                $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return false;
                }
                /**
                 * @var $conn Database
                 */
                $conn = $status->value;
                $superuser = $this->getVar( '_InstallUser' );

                $row = $conn->selectRow( '"pg_catalog"."pg_roles"', '*',
                        [ 'rolname' => $superuser ], __METHOD__ );

                return $row;
        }

        protected function canCreateAccounts() {
                $perms = $this->getInstallUserPermissions();
                if ( !$perms ) {
                        return false;
                }

                return $perms->rolsuper === 't' || $perms->rolcreaterole === 't';
        }

        protected function isSuperUser() {
                $perms = $this->getInstallUserPermissions();
                if ( !$perms ) {
                        return false;
                }

                return $perms->rolsuper === 't';
        }

        public function getSettingsForm() {
                if ( $this->canCreateAccounts() ) {
                        $noCreateMsg = false;
                } else {
                        $noCreateMsg = 'config-db-web-no-create-privs';
                }
                $s = $this->getWebUserBox( $noCreateMsg );

                return $s;
        }

        public function submitSettingsForm() {
                $status = $this->submitWebUserBox();
                if ( !$status->isOK() ) {
                        return $status;
                }

                $same = $this->getVar( 'wgDBuser' ) === $this->getVar( '_InstallUser' );

                if ( $same ) {
                        $exists = true;
                } else {
                        // Check if the web user exists
                        // Connect to the database with the install user
                        $status = $this->getPgConnection( 'create-db' );
                        if ( !$status->isOK() ) {
                                return $status;
                        }
                        $exists = $status->value->roleExists( $this->getVar( 'wgDBuser' ) );
                }

                // Validate the create checkbox
                if ( $this->canCreateAccounts() && !$same && !$exists ) {
                        $create = $this->getVar( '_CreateDBAccount' );
                } else {
                        $this->setVar( '_CreateDBAccount', false );
                        $create = false;
                }

                if ( !$create && !$exists ) {
                        if ( $this->canCreateAccounts() ) {
                                $msg = 'config-install-user-missing-create';
                        } else {
                                $msg = 'config-install-user-missing';
                        }

                        return Status::newFatal( $msg, $this->getVar( 'wgDBuser' ) );
                }

                if ( !$exists ) {
                        // No more checks to do
                        return Status::newGood();
                }

                // Existing web account. Test the connection.
                $status = $this->openConnectionToAnyDB(
                        $this->getVar( 'wgDBuser' ),
                        $this->getVar( 'wgDBpassword' ) );
                if ( !$status->isOK() ) {
                        return $status;
                }

                // The web user is conventionally the table owner in PostgreSQL
                // installations. Make sure the install user is able to create
                // objects on behalf of the web user.
                if ( $same || $this->canCreateObjectsForWebUser() ) {
                        return Status::newGood();
                } else {
                        return Status::newFatal( 'config-pg-not-in-role' );
                }
        }

        /**
         * Returns true if the install user is able to create objects owned
         * by the web user, false otherwise.
         * @return bool
         */
        protected function canCreateObjectsForWebUser() {
                if ( $this->isSuperUser() ) {
                        return true;
                }

                $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return false;
                }
                $conn = $status->value;
                $installerId = $conn->selectField( '"pg_catalog"."pg_roles"', 'oid',
                        [ 'rolname' => $this->getVar( '_InstallUser' ) ], __METHOD__ );
                $webId = $conn->selectField( '"pg_catalog"."pg_roles"', 'oid',
                        [ 'rolname' => $this->getVar( 'wgDBuser' ) ], __METHOD__ );

                return $this->isRoleMember( $conn, $installerId, $webId, $this->maxRoleSearchDepth );
        }

        /**
         * Recursive helper for canCreateObjectsForWebUser().
         * @param Database $conn
         * @param int $targetMember Role ID of the member to look for
         * @param int $group Role ID of the group to look for
         * @param int $maxDepth Maximum recursive search depth
         * @return bool
         */
        protected function isRoleMember( $conn, $targetMember, $group, $maxDepth ) {
                if ( $targetMember === $group ) {
                        // A role is always a member of itself
                        return true;
                }
                // Get all members of the given group
                $res = $conn->select( '"pg_catalog"."pg_auth_members"', [ 'member' ],
                        [ 'roleid' => $group ], __METHOD__ );
                foreach ( $res as $row ) {
                        if ( $row->member == $targetMember ) {
                                // Found target member
                                return true;
                        }
                        // Recursively search each member of the group to see if the target
                        // is a member of it, up to the given maximum depth.
                        if ( $maxDepth > 0 ) {
                                if ( $this->isRoleMember( $conn, $targetMember, $row->member, $maxDepth - 1 ) ) {
                                        // Found member of member
                                        return true;
                                }
                        }
                }

                return false;
        }

        public function preInstall() {
                $createDbAccount = [
                        'name' => 'user',
                        'callback' => [ $this, 'setupUser' ],
                ];
                $commitCB = [
                        'name' => 'pg-commit',
                        'callback' => [ $this, 'commitChanges' ],
                ];
                $plpgCB = [
                        'name' => 'pg-plpgsql',
                        'callback' => [ $this, 'setupPLpgSQL' ],
                ];
                $schemaCB = [
                        'name' => 'schema',
                        'callback' => [ $this, 'setupSchema' ]
                ];

                if ( $this->getVar( '_CreateDBAccount' ) ) {
                        $this->parent->addInstallStep( $createDbAccount, 'database' );
                }
                $this->parent->addInstallStep( $commitCB, 'interwiki' );
                $this->parent->addInstallStep( $plpgCB, 'database' );
                $this->parent->addInstallStep( $schemaCB, 'database' );
        }

        function setupDatabase() {
                $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return $status;
                }
                $conn = $status->value;

                $dbName = $this->getVar( 'wgDBname' );

                $exists = $conn->selectField( '"pg_catalog"."pg_database"', '1',
                        [ 'datname' => $dbName ], __METHOD__ );
                if ( !$exists ) {
                        $safedb = $conn->addIdentifierQuotes( $dbName );
                        $conn->query( "CREATE DATABASE $safedb", __METHOD__ );
                }

                return Status::newGood();
        }

        function setupSchema() {
                // Get a connection to the target database
                $status = $this->getPgConnection( 'create-schema' );
                if ( !$status->isOK() ) {
                        return $status;
                }
                $conn = $status->value;

                // Create the schema if necessary
                $schema = $this->getVar( 'wgDBmwschema' );
                $safeschema = $conn->addIdentifierQuotes( $schema );
                $safeuser = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
                if ( !$conn->schemaExists( $schema ) ) {
                        try {
                                $conn->query( "CREATE SCHEMA $safeschema AUTHORIZATION $safeuser" );
                        } catch ( DBQueryError $e ) {
                                return Status::newFatal( 'config-install-pg-schema-failed',
                                        $this->getVar( '_InstallUser' ), $schema );
                        }
                }

                // Select the new schema in the current connection
                $conn->determineCoreSchema( $schema );

                return Status::newGood();
        }

        function commitChanges() {
                $this->db->commit( __METHOD__ );

                return Status::newGood();
        }

        function setupUser() {
                if ( !$this->getVar( '_CreateDBAccount' ) ) {
                        return Status::newGood();
                }

                $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return $status;
                }
                $conn = $status->value;

                $safeuser = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
                $safepass = $conn->addQuotes( $this->getVar( 'wgDBpassword' ) );

                // Check if the user already exists
                $userExists = $conn->roleExists( $this->getVar( 'wgDBuser' ) );
                if ( !$userExists ) {
                        // Create the user
                        try {
                                $sql = "CREATE ROLE $safeuser NOCREATEDB LOGIN PASSWORD $safepass";

                                // If the install user is not a superuser, we need to make the install
                                // user a member of the new user's group, so that the install user will
                                // be able to create a schema and other objects on behalf of the new user.
                                if ( !$this->isSuperUser() ) {
                                        $sql .= ' ROLE' . $conn->addIdentifierQuotes( $this->getVar( '_InstallUser' ) );
                                }

                                $conn->query( $sql, __METHOD__ );
                        } catch ( DBQueryError $e ) {
                                return Status::newFatal( 'config-install-user-create-failed',
                                        $this->getVar( 'wgDBuser' ), $e->getMessage() );
                        }
                }

                return Status::newGood();
        }

        function getLocalSettings() {
                $port = $this->getVar( 'wgDBport' );
                $schema = $this->getVar( 'wgDBmwschema' );

                return "# Postgres specific settings
\$wgDBport = \"{$port}\";
\$wgDBmwschema = \"{$schema}\";";
        }

        public function preUpgrade() {
                global $wgDBuser, $wgDBpassword;

                # Normal user and password are selected after this step, so for now
                # just copy these two
                $wgDBuser = $this->getVar( '_InstallUser' );
                $wgDBpassword = $this->getVar( '_InstallPassword' );
        }

        public function createTables() {
                $schema = $this->getVar( 'wgDBmwschema' );

                $status = $this->getConnection();
                if ( !$status->isOK() ) {
                        return $status;
                }

                /** @var $conn DatabasePostgres */
                $conn = $status->value;

                if ( $conn->tableExists( 'archive' ) ) {
                        $status->warning( 'config-install-tables-exist' );
                        $this->enableLB();

                        return $status;
                }

                $conn->begin( __METHOD__ );

                if ( !$conn->schemaExists( $schema ) ) {
                        $status->fatal( 'config-install-pg-schema-not-exist' );

                        return $status;
                }
                $error = $conn->sourceFile( $this->getSchemaPath( $conn ) );
                if ( $error !== true ) {
                        $conn->reportQueryError( $error, 0, '', __METHOD__ );
                        $conn->rollback( __METHOD__ );
                        $status->fatal( 'config-install-tables-failed', $error );
                } else {
                        $conn->commit( __METHOD__ );
                }
                // Resume normal operations
                if ( $status->isOK() ) {
                        $this->enableLB();
                }

                return $status;
        }

        public function getGlobalDefaults() {
                // The default $wgDBmwschema is null, which breaks Postgres and other DBMSes that require
                // the use of a schema, so we need to set it here
                return array_merge( parent::getGlobalDefaults(), [
                        'wgDBmwschema' => 'mediawiki',
                ] );
        }

        public function setupPLpgSQL() {
                // Connect as the install user, since it owns the database and so is
                // the user that needs to run "CREATE LANGAUGE"
                $status = $this->getPgConnection( 'create-schema' );
                if ( !$status->isOK() ) {
                        return $status;
                }
                /**
                 * @var $conn Database
                 */
                $conn = $status->value;

                $exists = $conn->selectField( '"pg_catalog"."pg_language"', 1,
                        [ 'lanname' => 'plpgsql' ], __METHOD__ );
                if ( $exists ) {
                        // Already exists, nothing to do
                        return Status::newGood();
                }

                // plpgsql is not installed, but if we have a pg_pltemplate table, we
                // should be able to create it
                $exists = $conn->selectField(
                        [ '"pg_catalog"."pg_class"', '"pg_catalog"."pg_namespace"' ],
                        1,
                        [
                                'pg_namespace.oid=relnamespace',
                                'nspname' => 'pg_catalog',
                                'relname' => 'pg_pltemplate',
                        ],
                        __METHOD__ );
                if ( $exists ) {
                        try {
                                $conn->query( 'CREATE LANGUAGE plpgsql' );
                        } catch ( DBQueryError $e ) {
                                return Status::newFatal( 'config-pg-no-plpgsql', $this->getVar( 'wgDBname' ) );
                        }
                } else {
                        return Status::newFatal( 'config-pg-no-plpgsql', $this->getVar( 'wgDBname' ) );
                }

                return Status::newGood();
        }
}