ENH: allow server startup without running ddl and thus allowing starting with the database not yet up and later lazily initializing the database and running ddl

ebean-test/src/test/java/io/ebean/EbeanServerFactory_MultiTenancy_Test.java

@@ -44,7 +44,38 @@ public class EbeanServerFactory_MultiTenancy_Test extends BaseTestCase {
     database.shutdown();
   }
 
+  /**
+   *  Tests using multi tenancy per database
+   */
+  @Test
+  public void create_new_server_with_multi_tenancy_db_with_master() {
 
+    String tenant = "customer";
+    CurrentTenantProvider tenantProvider = Mockito.mock(CurrentTenantProvider.class);
+    Mockito.doReturn(tenant).when(tenantProvider).currentId();
+
+    TenantDataSourceProvider dataSourceProvider = Mockito.mock(TenantDataSourceProvider.class);
+
+    DatabaseConfig config = new DatabaseConfig();
+
+    config.setName("h2");
+    config.loadFromProperties();
+    config.setRegister(false);
+    config.setDefaultServer(false);
+    config.setDdlGenerate(false);
+    config.setDdlRun(false);
+
+    config.setTenantMode(TenantMode.DB_WITH_MASTER);
+    config.setCurrentTenantProvider(tenantProvider);
+    config.setTenantDataSourceProvider(dataSourceProvider);
+
+    Mockito.doReturn(config.getDataSource()).when(dataSourceProvider).dataSource(tenant);
+
+    config.setDatabasePlatform(new PostgresPlatform());
+
+    final Database database = DatabaseFactory.create(config);
+    database.shutdown();
+  }
 
   /**
    *  Tests using multi tenancy per schema

ebean-test/src/test/java/io/ebean/config/TestServerOffline.java

@@ -0,0 +1,163 @@
+package io.ebean.config;
+
+
+import io.ebean.Database;
+import io.ebean.DatabaseFactory;
+import io.ebean.annotation.ForPlatform;
+import io.ebean.annotation.Platform;
+import io.ebean.datasource.DataSourceAlert;
+import io.ebean.datasource.DataSourceInitialiseException;
+
+import org.junit.jupiter.api.Test;
+import org.tests.model.basic.EBasicVer;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Properties;
+
+import javax.persistence.PersistenceException;
+import javax.sql.DataSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class TestServerOffline {
+
+  @Test
+  @ForPlatform({Platform.H2})
+  public void testOffline_with_failOnStart() throws SQLException {
+
+    String url = "jdbc:h2:mem:testoffline1";
+    try (Connection bootup = DriverManager.getConnection(url, "sa", "secret")) {
+      Properties props = props(url);
+      props.setProperty("datasource.h2_offline.failOnStart", "true");
+      DatabaseConfig config = config(props);
+      assertThatThrownBy(() -> DatabaseFactory.create(config))
+        .isInstanceOf(DataSourceInitialiseException.class);
+   }
+
+  }
+
+  @Test
+  @ForPlatform({Platform.H2})
+  public void testOffline_no_failOnStart() throws SQLException {
+
+    String url = "jdbc:h2:mem:testoffline2";
+    try (Connection bootup = DriverManager.getConnection(url, "sa", "secret")) {
+      Properties props = props(url);
+
+      DatabaseConfig config = config(props);
+      config.setSkipDataSourceCheck(true);
+      config.setSkipInitDatabase(true);
+      Database h2Offline = DatabaseFactory.create(config);
+      assertThat(h2Offline).isNotNull();
+    }
+  }
+
+  private static class LazyDatasourceInitializer implements DataSourceAlert {
+
+    public Database server;
+
+    private boolean initialized;
+
+    @Override
+    public void dataSourceUp(DataSource dataSource) {
+      if (!initialized) {
+        initDatabase();
+      }
+    }
+
+    public synchronized void initDatabase() {
+      if (!initialized) {
+        server.initDatabase(true);
+        initialized = true;
+      }
+    }
+
+    @Override
+    public void dataSourceDown(DataSource dataSource, SQLException reason) {}
+
+    @Override
+    public void dataSourceWarning(DataSource dataSource, String msg) {}
+
+  }
+
+  @Test
+  @ForPlatform({Platform.H2})
+  public void testOffline_recovery() throws SQLException {
+
+    String url = "jdbc:h2:mem:testoffline3";
+    try (Connection bootup = DriverManager.getConnection(url, "sa", "secret")) {
+
+      Properties props = props(url);
+      LazyDatasourceInitializer alert = new LazyDatasourceInitializer() ;
+
+      DatabaseConfig config = config(props);
+
+      config.getDataSourceConfig().setAlert(alert);
+      config.getDataSourceConfig().setHeartbeatFreqSecs(1);
+      config.setSkipDataSourceCheck(true);
+      config.setSkipInitDatabase(true);
+
+      Database h2Offline = DatabaseFactory.create(config);
+      alert.server = h2Offline;
+      assertThat(h2Offline).isNotNull();
+
+      assertThatThrownBy(() -> alert.initDatabase())
+        .isInstanceOf(PersistenceException.class)
+        .hasMessageContaining("Failed to obtain connection to run DDL");
+
+      assertThatThrownBy(() -> h2Offline.find(EBasicVer.class).findCount()).isInstanceOf(PersistenceException.class);
+
+      // so - reset the password so that the server can reconnect
+      try (Statement stmt = bootup.createStatement()) {
+        stmt.execute("alter user sa set password 'sa'");
+      }
+
+      assertThat(alert.initialized).isFalse();
+      // next access to ebean should bring DS online
+      h2Offline.find(EBasicVer.class).findCount();
+      assertThat(alert.initialized).isTrue();
+
+      // check if server is working (ie ddl was run)
+      EBasicVer bean = new EBasicVer("foo");
+      h2Offline.save(bean);
+      assertThat(h2Offline.find(EBasicVer.class).findCount()).isEqualTo(1);
+      h2Offline.delete(bean);
+    }
+  }
+
+  private Properties props(String url) {
+
+    Properties props = new Properties();
+
+    props.setProperty("datasource.h2_offline.username", "sa");
+    props.setProperty("datasource.h2_offline.password", "sa");
+    props.setProperty("datasource.h2_offline.url", url);
+    props.setProperty("datasource.h2_offline.driver", "org.h2.Driver");
+
+    // ensures, that the datasource will come up when DB is not available
+    props.setProperty("datasource.h2_offline.failOnStart", "false");
+
+    props.setProperty("ebean.h2_offline.databasePlatformName", "h2");
+    props.setProperty("ebean.h2_offline.ddl.extra", "false");
+
+    props.setProperty("ebean.h2_offline.ddl.generate", "true");
+    props.setProperty("ebean.h2_offline.ddl.run", "true");
+
+    return props;
+  }
+
+  private DatabaseConfig config(Properties props) {
+    DatabaseConfig config = new DatabaseConfig();
+    config.setName("h2_offline");
+    config.loadFromProperties(props);
+    config.setDefaultServer(false);
+    config.setRegister(false);
+    config.getClasses().add(EBasicVer.class);
+    return config;
+  }
+
+}

ebean-test/src/test/java/io/ebeaninternal/api/TDSpiServer.java

@@ -583,6 +583,11 @@ public class TDSpiServer implements SpiServer {
     return null;
   }
 
+  @Override
+  public void initDatabase(final boolean online) {
+
+  }
+
   @Override
   public void truncate(String... tables) {