support empty password for mysql

modules/jdbc-test/src/test/java/org/testcontainers/junit/EmptyPasswordMysqlTest.java

@@ -0,0 +1,46 @@
+package org.testcontainers.junit;
+
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
+import org.junit.Rule;
+import org.junit.Test;
+import org.testcontainers.containers.MySQLContainer;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import static org.rnorth.visibleassertions.VisibleAssertions.assertEquals;
+
+public class EmptyPasswordMysqlTest {
+    private static final String DB_NAME = "foo";
+    private static final String USER = "root"; // MySQL allows empty password with root only
+
+    // Add MYSQL_ROOT_HOST environment so that we can root login from anywhere for testing purposes
+    @Rule
+    public MySQLContainer mysql = (MySQLContainer) new MySQLContainer("mysql:5.5")
+            .withDatabaseName(DB_NAME)
+            .withUsername(USER)
+            .withPassword("")
+            .withEnv("MYSQL_ROOT_HOST", "%");
+
+    @Test
+    public void testSimple() throws SQLException {
+        HikariConfig hikariConfig = new HikariConfig();
+        hikariConfig.setJdbcUrl("jdbc:mysql://"
+                + mysql.getContainerIpAddress()
+                + ":" + mysql.getMappedPort(MySQLContainer.MYSQL_PORT)
+                + "/" + DB_NAME);
+        hikariConfig.setUsername(USER);
+        hikariConfig.setPassword("");
+
+        HikariDataSource ds = new HikariDataSource(hikariConfig);
+        Statement statement = ds.getConnection().createStatement();
+        statement.execute("SELECT 1");
+        ResultSet resultSet = statement.getResultSet();
+
+        assertEquals("There is a result", resultSet.next(), true);
+        int resultSetInt = resultSet.getInt(1);
+        assertEquals("A basic SELECT query succeeds", 1, resultSetInt);
+    }
+}

modules/jdbc-test/src/test/java/org/testcontainers/junit/SimpleMySQLTest.java

@@ -4,7 +4,9 @@
 import com.zaxxer.hikari.HikariDataSource;
 import lombok.NonNull;
 import org.apache.commons.lang.SystemUtils;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.testcontainers.containers.MySQLContainer;
@@ -43,6 +45,9 @@ public class SimpleMySQLTest {
                                                             .withConfigurationOverride("somepath/mysql_conf_override");
     */
 
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
     @Test
     public void testSimple() throws SQLException {
         MySQLContainer mysql = (MySQLContainer) new MySQLContainer()
@@ -128,6 +133,20 @@ public void testMySQL8() throws SQLException {
         }
     }
 
+    @Test
+    public void testEmptyPasswordWithNonRootUser() {
+      thrown.expect(RuntimeException.class);
+
+      MySQLContainer container = (MySQLContainer) new MySQLContainer("mysql:5.5")
+      .withDatabaseName("TEST")
+      .withUsername("test")
+      .withPassword("")
+      .withEnv("MYSQL_ROOT_HOST", "%");
+
+      container.start();
+      container.stop();
+    }
+
     @NonNull
     protected ResultSet performQuery(MySQLContainer containerRule, String sql) throws SQLException {
         HikariConfig hikariConfig = new HikariConfig();

modules/mysql/src/main/java/org/testcontainers/containers/MySQLContainer.java

@@ -41,8 +41,16 @@ protected void configure() {
         addExposedPort(MYSQL_PORT);
         addEnv("MYSQL_DATABASE", databaseName);
         addEnv("MYSQL_USER", username);
-        addEnv("MYSQL_PASSWORD", password);
-        addEnv("MYSQL_ROOT_PASSWORD", password);
+        if(password != null && !password.isEmpty()){
+          addEnv("MYSQL_PASSWORD", password);
+          addEnv("MYSQL_ROOT_PASSWORD", password);
+        } else {
+          if("root".equalsIgnoreCase(username)){
+            addEnv("MYSQL_ALLOW_EMPTY_PASSWORD", "yes");
+          } else {
+            throw new RuntimeException("Empty password can be used only with the root user");
+          }
+        }
         setStartupAttempts(3);
     }