From d69d7e82b8bbb567668c935ace848c7dcf750b08 Mon Sep 17 00:00:00 2001 From: Thomas Lange Date: Thu, 24 Jun 2021 21:09:24 +0200 Subject: Implement database schema Migrator This commit implements the new database schema Migrator which keeps track of the on-disk schema and the schema used by the codebase. It tries to makes future database schema upgrades user-friendlier. --- core/application.php | 5 ++ core/migrations.php | 43 ++++++++++ core/namespace/Application.php | 14 ++++ core/namespace/Migrator.php | 182 +++++++++++++++++++++++++++++++++++++++++ theme/admin/html/main.php | 2 +- theme/admin/html/migration.php | 59 +++++++++++++ theme/admin/lang/de.php | 10 +++ theme/admin/lang/en.php | 10 +++ theme/admin/rsrc/css/main.css | 31 +++++-- theme/admin/rsrc/css/main.scss | 32 ++++++-- 10 files changed, 369 insertions(+), 19 deletions(-) create mode 100644 core/migrations.php create mode 100644 core/namespace/Migrator.php create mode 100644 theme/admin/html/migration.php diff --git a/core/application.php b/core/application.php index 21ab203..d6c9bd0 100644 --- a/core/application.php +++ b/core/application.php @@ -141,6 +141,11 @@ require 'functions.php'; $Language = Application::getLanguage(); $Database = Application::getDatabase(); +#=============================================================================== +# Include migration detection +#=============================================================================== +require 'migrations.php'; + #=============================================================================== # Check if "304 Not Modified" and ETag header should be sent #=============================================================================== diff --git a/core/migrations.php b/core/migrations.php new file mode 100644 index 0000000..f2c9714 --- /dev/null +++ b/core/migrations.php @@ -0,0 +1,43 @@ +isMigrationNeeded()) { + @session_start(); + + Application::set('TEMPLATE.NAME', Application::get('ADMIN.TEMPLATE')); + Application::set('TEMPLATE.LANG', Application::get('ADMIN.LANGUAGE')); + Application::getLanguage(TRUE); // Force recreation of Language object + + if(HTTP::issetPOST(['token' => Application::getSecurityToken()], 'run')) { + if(!$migrated = $Migrator->runMigrations()) { + Application::exit('CONFUSED: No migrations were performed?!'); + } + } + + $Template = Template\Factory::build('migration'); + $Template->set('MIGRATION', [ + 'LIST' => $Migrator->getMigrations(), + 'SUCCESSFUL' => $migrated ?? [], + 'SCHEMA_VERSION' => [ + 'DATABASE' => $Migrator->getVersionFromTable(), + 'CODEBASE' => $Migrator::CURRENT_SCHEMA_VERSION + ], + ]); + + Application::exit($Template); +} + +#=============================================================================== +# Check for an unsupported downgrade attempt +#=============================================================================== +else if($Migrator->isDowngradeAttempt()) { + throw new Exception('MIGRATOR: The schema version used by *your* database is + higher than the schema version defined in the codebase. It is officially + not supported to automatically downgrade the database schema version!'); +} diff --git a/core/namespace/Application.php b/core/namespace/Application.php index 3cecf3b..829f758 100644 --- a/core/namespace/Application.php +++ b/core/namespace/Application.php @@ -6,6 +6,7 @@ class Application { #=============================================================================== private static $Database; private static $Language; + private static $Migrator; private static $repositories = []; #=============================================================================== @@ -80,6 +81,19 @@ class Application { return self::$Language; } + #=============================================================================== + # Return singleton Migrator instance + #=============================================================================== + public static function getMigrator(): Migrator { + if(!self::$Migrator instanceof Migrator) { + $Migrator = new Migrator(self::getDatabase()); + $Migrator->setMigrationsDir(ROOT.'core/db/migrations/'); + self::$Migrator = $Migrator; + } + + return self::$Migrator; + } + #=============================================================================== # Return singleton repository instance #=============================================================================== diff --git a/core/namespace/Migrator.php b/core/namespace/Migrator.php new file mode 100644 index 0000000..3096862 --- /dev/null +++ b/core/namespace/Migrator.php @@ -0,0 +1,182 @@ +Database = $Database; + + try { + $Statement = $Database->query('SELECT schema_version FROM migration'); + + if(!$this->version = $Statement->fetchColumn()) { + throw new Exception('The migration table does exist, but there is + no row containing the currently used on-disk schema version!'); + } + } catch(PDOException $Exception) { + if($Exception->getCode() === '42S02') /* Table not found */ { + $this->version = $this->determineFallbackSchemaVersion(); + $this->createMigrationTable($this->version); + } else { + throw $Exception; + } + } + } + + #=============================================================================== + # Specify the directory which contains the migration files + #=============================================================================== + public function setMigrationsDir(string $directory): void { + if(!is_readable($this->directory = rtrim($directory, '/'))) { + throw new Exception('Migrator cannot read migration directory.'); + }; + } + + #=============================================================================== + # Check if new migrations needs to be applied + #=============================================================================== + public function isMigrationNeeded(): bool { + $databaseSchema = $this->version; + $codebaseSchema = self::CURRENT_SCHEMA_VERSION; + return $databaseSchema < $codebaseSchema; + } + + #=============================================================================== + # Check if this is an unsupported downgrade attempt + #=============================================================================== + public function isDowngradeAttempt(): bool { + $databaseSchema = $this->version; + $codebaseSchema = self::CURRENT_SCHEMA_VERSION; + return $databaseSchema > $codebaseSchema; + } + + #=============================================================================== + # Add a migration to the queue + #=============================================================================== + private function enqueue(int $sequence, string $migration): void { + $this->migrations[$sequence] = $migration; + } + + #=============================================================================== + # Remove a migration from the queue + #=============================================================================== + private function dequeue(int $sequence): void { + unset($this->migrations[$sequence]); + } + + #=============================================================================== + # Get the currently used on-disk schema version + #=============================================================================== + public function getVersionFromTable(): int { + return $this->version; + } + + #=============================================================================== + # Get an array with all migration commands + #=============================================================================== + public function getMigrations(): array { + $databaseSchema = $this->version; + $codebaseSchema = self::CURRENT_SCHEMA_VERSION; + + if(!$this->isMigrationNeeded()) { + return []; + } + + foreach(range($databaseSchema+1, $codebaseSchema) as $number) { + $file = sprintf("%s/%d.sql", $this->directory, $number); + + if(!is_readable($file)) { + throw new Exception("Migrator cannot read migration file: »{$file}«"); + } + $this->enqueue($number, file_get_contents($file)); + } + + return $this->migrations; + } + + #=============================================================================== + # Run migrations sequentially + #=============================================================================== + public function runMigrations(): array { + foreach($this->getMigrations() as $sequence => $migration) { + try { + if($this->Database->query($migration)) { + $this->dequeue($sequence); + $this->updateMigrationTable($sequence); + $migrated[] = $sequence; + } + } catch(PDOException $Exception) { + $error = 'Migration from %d to %d failed with PDO error:
'; + $error .= sprintf($error, $sequence-1, $sequence); + $error .= sprintf('%s', $Exception->getMessage()); + + if(!empty($migrated ?? [])) { + $error .= '
The following migrations were successful: '; + $error .= ''.implode(', ', $migrated).''; + } + + throw new Exception($error); + } + } + + return $migrated ?? []; + } + + #=============================================================================== + # Update the migration table with the specified schema version + #=============================================================================== + private function updateMigrationTable(int $version): int { + $query = 'UPDATE migration SET schema_version = ?'; + $Statement = $this->Database->prepare($query); + + if($Statement->execute([$version])) { + return $this->version = $version; + } + } + + #=============================================================================== + # Create the migration table with the specified schema version + #=============================================================================== + private function createMigrationTable(int $version): bool { + $create = 'CREATE TABLE migration (schema_version smallint(4) NOT NULL) + ENGINE=InnoDB DEFAULT CHARSET=utf8mb4'; + $insert = 'INSERT INTO migration (schema_version) VALUES (?)'; + + $this->Database->query($create); + $Statement = $this->Database->prepare($insert); + + return $Statement->execute([$version]); + } + + #=============================================================================== + # Determine on-disk schema version if migration table does not exist + #=============================================================================== + private function determineFallbackSchemaVersion(): int { + # If the migration table does not yet exist, the user may have upgraded from + # an older release of the application and sits somewhere between 0 and 4. So + # we run some checks against the tables to determine the schema version. + $test[4] = 'SHOW COLUMNS FROM post WHERE Field = "argv" AND Type = "varchar(250)"'; + $test[3] = 'SHOW INDEX FROM post WHERE Key_name = "search"'; + $test[2] = 'SHOW INDEX FROM post WHERE Key_name = "time_insert"'; + $test[1] = 'SHOW COLUMNS FROM post WHERE Field = "argv"'; + + foreach($test as $version => $query) { + try { + $Statement = $this->Database->query($query); + + if ($Statement && $Statement->fetch()) { + return $version; + } + } catch(PDOException $Exception) {} + } + + return 0; + } +} diff --git a/theme/admin/html/main.php b/theme/admin/html/main.php index a7772ed..db637da 100644 --- a/theme/admin/html/main.php +++ b/theme/admin/html/main.php @@ -10,7 +10,7 @@
-
+
diff --git a/theme/admin/html/migration.php b/theme/admin/html/migration.php new file mode 100644 index 0000000..14405c4 --- /dev/null +++ b/theme/admin/html/migration.php @@ -0,0 +1,59 @@ + + + + + + + + <?=$Language->text('maintenance_mode')?> + + +
+
+
+ +
+
text('maintenance_mode')?>
+
+
+
+ +
+

text('maintenance_mode')?>

+ +

text('migration_successful')?>

+
    + +
  • Migration
    • + +
+ +

text("migration_upgrade", [$database_schema, $codebase_schema])?>

+
+
    + $commands): ?> +
  • +

    Migration

    +

    text('migration_notice', [$migration-1, $migration])?>

    +
    +
    • + +
+ + +
+ +
+ + + diff --git a/theme/admin/lang/de.php b/theme/admin/lang/de.php index 0a848a6..3c7e834 100644 --- a/theme/admin/lang/de.php +++ b/theme/admin/lang/de.php @@ -143,3 +143,13 @@ $LANGUAGE['markdown_code'] = 'Codeblock'; $LANGUAGE['markdown_quote'] = 'Zitat'; $LANGUAGE['markdown_list_ul'] = 'Liste [ungeordnet]'; $LANGUAGE['markdown_list_ol'] = 'Liste [geordnet]'; + +#=============================================================================== +# Migrations +#=============================================================================== +$LANGUAGE['maintenance_mode'] = 'Wartungsmodus'; +$LANGUAGE['migration_upgrade'] = 'Eine Migration des Datenbankschemas ist erforderlich!
Die Datenbank verwendet die + Schema-Version %d, aber die Applikation benutzt die höhere Schema-Version %d.'; +$LANGUAGE['migration_notice'] = 'Die folgenden Kommandos migrieren das Datenbankschema von %d nach %d.'; +$LANGUAGE['migration_successful'] = 'Die folgenden Migrationen waren erfolgreich:'; +$LANGUAGE['migration_submit'] = 'Migrationen ausführen'; diff --git a/theme/admin/lang/en.php b/theme/admin/lang/en.php index 174a1d7..20482d4 100644 --- a/theme/admin/lang/en.php +++ b/theme/admin/lang/en.php @@ -143,3 +143,13 @@ $LANGUAGE['markdown_code'] = 'Code block'; $LANGUAGE['markdown_quote'] = 'Quote'; $LANGUAGE['markdown_list_ul'] = 'List [unordered]'; $LANGUAGE['markdown_list_ol'] = 'List [ordered]'; + +#=============================================================================== +# Migrations +#=============================================================================== +$LANGUAGE['maintenance_mode'] = 'Maintenance mode'; +$LANGUAGE['migration_upgrade'] = 'A database schema migration is required!
The on-disk schema version is + %d but the application uses the higher schema version %d.'; +$LANGUAGE['migration_notice'] = 'The following commands will migrate the database schema from %d to %d.'; +$LANGUAGE['migration_successful'] = 'The following migrations were successful:'; +$LANGUAGE['migration_submit'] = 'Run migrations'; diff --git a/theme/admin/rsrc/css/main.css b/theme/admin/rsrc/css/main.css index cfc6db9..7d93d94 100644 --- a/theme/admin/rsrc/css/main.css +++ b/theme/admin/rsrc/css/main.css @@ -140,18 +140,18 @@ body { .header-line { padding: 0.5rem 0.75rem; overflow: hidden; -} -.header-line:first-child { - background: #5E819F; - position: sticky; - top: 0; -} -.header-line:last-child { background: #EEE; + padding: 0.25rem 0.75rem; +} +.header-line + .header-line { border: 0.05rem solid #AAA; border-left: none; border-right: none; - padding: 0.25rem 0.75rem; +} +.header-line.background { + background: #5E819F; + position: sticky; + top: 0; } /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ @@ -308,11 +308,18 @@ pre { overflow: auto; -moz-tab-size: 4; tab-size: 4; + background: #EEE; + padding: 0.5rem; + border: 0.05rem solid #AAA; + font-style: italic; } code, pre { font-family: "monospace"; - color: #B03060; +} + +code { + color: #008B45; } p { @@ -344,6 +351,12 @@ img { display: none; } +.no-visual-list { + margin: 0; + padding: 0; + list-style: none; +} + #database-result { color: inherit; } diff --git a/theme/admin/rsrc/css/main.scss b/theme/admin/rsrc/css/main.scss index d1f43c9..cc9bbb1 100644 --- a/theme/admin/rsrc/css/main.scss +++ b/theme/admin/rsrc/css/main.scss @@ -145,19 +145,20 @@ body { .header-line { padding: 0.5rem 0.75rem; overflow: hidden; + background: #EEE; - &:first-child { - background: #5E819F; - position: sticky; - top: 0; - } + padding: 0.25rem 0.75rem; - &:last-child { - background: #EEE; + +.header-line { border: 0.05rem solid #AAA; border-left: none; border-right: none; - padding: 0.25rem 0.75rem; + } + + &.background { + background: #5E819F; + position: sticky; + top: 0; } } @@ -341,11 +342,18 @@ pre { overflow: auto; -moz-tab-size: 4; tab-size: 4; + background: #EEE; + padding: 0.5rem; + border: 0.05rem solid #AAA; + font-style: italic; } code, pre { font-family: "monospace"; - color: #B03060; +} + +code { + color: #008B45; } p { @@ -377,6 +385,12 @@ img { display: none; } +.no-visual-list { + margin: 0; + padding: 0; + list-style: none; +} + #database-result { color: inherit; } -- cgit v1.2.3