Minimise dependencies on Log4j2

Closes gh-15441

spring-boot-project/spring-boot-tools/spring-boot-test-support/src/main/java/org/springframework/boot/testsupport/testcontainers/Container.java

@@ -77,6 +77,10 @@ class Container implements TestRule {
 		return this.container.getMappedPort(this.port);
 	}
 
+	protected GenericContainer<?> getContainer() {
+		return this.container;
+	}
+
 	private static class SkipStatement extends Statement {
 
 		@Override

spring-boot-project/spring-boot-tools/spring-boot-test-support/src/main/java/org/springframework/boot/testsupport/testcontainers/ElasticsearchContainer.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.testsupport.testcontainers;
+
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+/**
+ * A {@link Container} for Elasticsearch.
+ *
+ * @author Andy Wilkinson
+ */
+public class ElasticsearchContainer extends Container {
+
+	public ElasticsearchContainer() {
+		super("elasticsearch:6.4.3", 9200, (container) -> container.addExposedPort(9300));
+	}
+
+	public int getMappedTransportPort() {
+		return getContainer().getMappedPort(9300);
+	}
+
+	@Override
+	public Statement apply(Statement base, Description description) {
+		Statement wrapped = super.apply(base, description);
+		return new Statement() {
+
+			@Override
+			public void evaluate() throws Throwable {
+				System.setProperty("es.set.netty.runtime.available.processors", "false");
+				try {
+					wrapped.evaluate();
+				}
+				finally {
+					System.clearProperty("es.set.netty.runtime.available.processors");
+				}
+			}
+
+		};
+
+	}
+
+}