Upgrades MySql for testing to 8.0.24.

This version of the docker container doesn't allow to use `root` as the database user name.
We still have to connect as `root` so we can create alternative schemata.

Author: schauder

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/testing/MySqlDataSourceConfiguration.java

@@ -52,9 +52,9 @@ protected DataSource createDataSource() {
 
 		if (MYSQL_CONTAINER == null) {
 
-			MySQLContainer<?> container = new MySQLContainer<>()
-					.withUsername("root")
-					.withPassword("")
+			MySQLContainer<?> container = new MySQLContainer<>("mysql:8.0.24")
+					.withUsername("test")
+					.withPassword("test")
 					.withConfigurationOverride("");
 
 			container.start();
@@ -64,7 +64,7 @@ protected DataSource createDataSource() {
 
 		MysqlDataSource dataSource = new MysqlDataSource();
 		dataSource.setUrl(MYSQL_CONTAINER.getJdbcUrl());
-		dataSource.setUser(MYSQL_CONTAINER.getUsername());
+		dataSource.setUser("root");
 		dataSource.setPassword(MYSQL_CONTAINER.getPassword());
 		dataSource.setDatabaseName(MYSQL_CONTAINER.getDatabaseName());
 
@@ -79,4 +79,15 @@ public void initDatabase() throws SQLException {
 					new ByteArrayResource("DROP DATABASE test;CREATE DATABASE test;".getBytes()));
 		}
 	}
+
+	private DataSource createRootDataSource() {
+
+		MysqlDataSource dataSource = new MysqlDataSource();
+		dataSource.setUrl(MYSQL_CONTAINER.getJdbcUrl());
+		dataSource.setUser("root");
+		dataSource.setPassword(MYSQL_CONTAINER.getPassword());
+		dataSource.setDatabaseName(MYSQL_CONTAINER.getDatabaseName());
+
+		return dataSource;
+	}
 }