Drupal 9+ SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED, fixes …

…#4281 (#4351) [skip ci]

docs/content/users/topics/cms_specific_help.md

@@ -25,6 +25,9 @@ This helps new users and people who are kicking the tires on a CMS. Plus it’s
 ### Drupal Specifics
 
 * **Settings Files**: By default, DDEV will create settings files for your project that make it “just work” out of the box. It creates a `sites/default/settings.ddev.php` and adds an include in `sites/default/settings.php` to bring that in. There are guards to prevent the `settings.ddev.php` from being active when the project is not running under DDEV, but it still should not be checked in and is gitignored.
+* **Database requirements for Drupal 9.5+ +**:
+    * Using MySQL or MariaDB, Drupal requires `SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED` and DDEV does this for you on `ddev start`.
+    * Using PostgreSQL, Drupal requires the`pg_trm` extension. DDEV creates this extension automatically for you on `ddev start`.
 * **Twig Debugging**: With the default Drupal configuration, it’s very difficult to debug Twig templates; you need to use `development.services.yml` instead of `services.yml`. Add this line in your `settings.php` or `settings.local.php`. See discussion at [drupal.org](https://www.drupal.org/forum/support/module-development-and-code-questions/2019-09-02/ddev-twig-debugging) and the Drupal documentation.
 
 ```php

pkg/ddevapp/drupal.go

@@ -382,15 +382,28 @@ func drupal8PostStartAction(app *DdevApp) error {
 }
 
 func drupalPostStartAction(app *DdevApp) error {
-	// pg_trm extension is required
-	if app.Database.Type == nodeps.Postgres && (isDrupal9App(app) || isDrupal10App(app)) {
-		stdout, stderr, err := app.Exec(&ExecOpts{
-			Service:   "db",
-			Cmd:       `psql -q -c "CREATE EXTENSION IF NOT EXISTS pg_trgm;" 2>/dev/null`,
-			NoCapture: false,
-		})
-		if err != nil {
-			util.Warning("unable to CREATE EXTENSION pg_trm: stdout='%s', stderr='%s', err=%v", stdout, stderr, err)
+	if isDrupal9App(app) || isDrupal10App(app) {
+		// pg_trm extension is required in Drupal9.5+
+		if app.Database.Type == nodeps.Postgres {
+			stdout, stderr, err := app.Exec(&ExecOpts{
+				Service:   "db",
+				Cmd:       `psql -q -c "CREATE EXTENSION IF NOT EXISTS pg_trgm;" 2>/dev/null`,
+				NoCapture: false,
+			})
+			if err != nil {
+				util.Warning("unable to CREATE EXTENSION pg_trm: stdout='%s', stderr='%s', err=%v", stdout, stderr, err)
+			}
+		}
+		// SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED required in Drupal 9.5+
+		if app.Database.Type == nodeps.MariaDB || app.Database.Type == nodeps.MySQL {
+			stdout, stderr, err := app.Exec(&ExecOpts{
+				Service:   "db",
+				Cmd:       `mysql -e "SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED;" 2>/dev/null`,
+				NoCapture: false,
+			})
+			if err != nil {
+				util.Warning("unable to SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED: stdout='%s', stderr='%s', err=%v", stdout, stderr, err)
+			}
 		}
 	}
 	// Return early because we aren't expected to manage settings.

pkg/ddevapp/drupal/drupal10/settings.ddev.php

@@ -28,13 +28,6 @@
   'prefix' => "{{ $config.DatabasePrefix }}",
 );
 
-
-// Setting the MySQL transaction isolation level.
-// @see https://www.drupal.org/docs/system-requirements/setting-the-mysql-transaction-isolation-level
-if ($driver === "mysql") {
-  $databases['default']['default']['init_commands']['isolation_level'] = 'SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED';
-}
-
 $settings['hash_salt'] = '{{ $config.HashSalt }}';
 
 // This will prevent Drupal from setting read-only permissions on sites/default.

pkg/ddevapp/drupal/drupal9/settings.ddev.php

@@ -28,13 +28,6 @@
   'prefix' => "{{ $config.DatabasePrefix }}",
 );
 
-
-// Setting the MySQL transaction isolation level.
-// @see https://www.drupal.org/docs/system-requirements/setting-the-mysql-transaction-isolation-level
-if ($driver === "mysql") {
-  $databases['default']['default']['init_commands']['isolation_level'] = 'SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED';
-}
-
 $settings['hash_salt'] = '{{ $config.HashSalt }}';
 
 // This will prevent Drupal from setting read-only permissions on sites/default.