Merge branch '2.2.x' into 2.3.x

Closes gh-22930

Author: snicoll

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/prometheus/PrometheusMetricsExportAutoConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -123,6 +123,12 @@ void allowsCustomScrapeEndpointToBeUsed() {
 						.hasBean("customEndpoint").hasSingleBean(PrometheusScrapeEndpoint.class));
 	}
 
+	@Test
+	void pushGatewayIsNotConfiguredWhenEnabledFlagIsNotSet() {
+		this.contextRunner.withUserConfiguration(BaseConfiguration.class)
+				.run((context) -> assertThat(context).doesNotHaveBean(PrometheusPushGatewayManager.class));
+	}
+
 	@Test
 	void withPushGatewayEnabled(CapturedOutput output) {
 		this.contextRunner.withConfiguration(AutoConfigurations.of(ManagementContextAutoConfiguration.class))

spring-boot-project/spring-boot-docs/src/docs/asciidoc/production-ready-features.adoc

@@ -1723,8 +1723,9 @@ To enable Prometheus Pushgateway support, add the following dependency to your p
 </dependency>
 ----
 
-When the Prometheus Pushgateway dependency is present on the classpath, Spring Boot auto-configures a `PrometheusPushGatewayManager` bean.
+When the Prometheus Pushgateway dependency is present on the classpath and the configprop:management.metrics.export.prometheus.pushgateway.enabled[] property is set to `true`, a `PrometheusPushGatewayManager` bean is auto-configured.
 This manages the pushing of metrics to a Prometheus Pushgateway.
+
 The `PrometheusPushGatewayManager` can be tuned using properties under `management.metrics.export.prometheus.pushgateway`.
 For advanced configuration, you can also provide your own `PrometheusPushGatewayManager` bean.