Update tag keys to comply with Micrometer recommendations

Closes gh-30536

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/cache/CacheMetricsRegistrarConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -72,7 +72,7 @@ class CacheMetricsRegistrarConfiguration {
 	}
 
 	private void bindCacheToRegistry(String beanName, Cache cache) {
-		Tag cacheManagerTag = Tag.of("cacheManager", getCacheManagerName(beanName));
+		Tag cacheManagerTag = Tag.of("cache.manager", getCacheManagerName(beanName));
 		this.cacheMetricsRegistrar.bindCacheToRegistry(cache, cacheManagerTag);
 	}
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/cache/CacheMetricsAutoConfigurationTests.java

@@ -44,8 +44,8 @@ class CacheMetricsAutoConfigurationTests {
 		this.contextRunner.withPropertyValues("spring.cache.type=cache2k", "spring.cache.cache-names=cache1,cache2")
 				.run((context) -> {
 					MeterRegistry registry = context.getBean(MeterRegistry.class);
-					registry.get("cache.gets").tags("name", "cache1").tags("cacheManager", "cacheManager").meter();
+					registry.get("cache.gets").tags("name", "cache1").tags("cache.manager", "cacheManager").meter();
-					registry.get("cache.gets").tags("name", "cache2").tags("cacheManager", "cacheManager").meter();
+					registry.get("cache.gets").tags("name", "cache2").tags("cache.manager", "cacheManager").meter();
 				});
 	}
 
@@ -54,8 +54,8 @@ class CacheMetricsAutoConfigurationTests {
 		this.contextRunner.withPropertyValues("spring.cache.type=caffeine", "spring.cache.cache-names=cache1,cache2")
 				.run((context) -> {
 					MeterRegistry registry = context.getBean(MeterRegistry.class);
-					registry.get("cache.gets").tags("name", "cache1").tags("cacheManager", "cacheManager").meter();
+					registry.get("cache.gets").tags("name", "cache1").tags("cache.manager", "cacheManager").meter();
-					registry.get("cache.gets").tags("name", "cache2").tags("cacheManager", "cacheManager").meter();
+					registry.get("cache.gets").tags("name", "cache2").tags("cache.manager", "cacheManager").meter();
 				});
 	}
 
@@ -64,9 +64,9 @@ class CacheMetricsAutoConfigurationTests {
 		this.contextRunner.withPropertyValues("spring.cache.type=simple", "spring.cache.cache-names=cache1,cache2")
 				.run((context) -> {
 					MeterRegistry registry = context.getBean(MeterRegistry.class);
-					assertThat(registry.find("cache.gets").tags("name", "cache1").tags("cacheManager", "cacheManager")
+					assertThat(registry.find("cache.gets").tags("name", "cache1").tags("cache.manager", "cacheManager")
 							.meter()).isNull();
-					assertThat(registry.find("cache.gets").tags("name", "cache2").tags("cacheManager", "cacheManager")
+					assertThat(registry.find("cache.gets").tags("name", "cache2").tags("cache.manager", "cacheManager")
 							.meter()).isNull();
 				});
 	}
@@ -77,7 +77,7 @@ class CacheMetricsAutoConfigurationTests {
 				"spring.cache.cache-names=cache1").run((context) -> {
 					MeterRegistry registry = context.getBean(MeterRegistry.class);
 					assertThat(registry.find("cache.requests").tags("name", "cache1")
-							.tags("cacheManager", "cacheManager").meter()).isNull();
+							.tags("cache.manager", "cacheManager").meter()).isNull();
 				});
 	}
 

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/graphql/GraphQlTags.java

@@ -41,7 +41,7 @@ public final class GraphQlTags {
 
 	private static final Tag OUTCOME_ERROR = Tag.of("outcome", "ERROR");
 
-	private static final Tag UNKNOWN_ERRORTYPE = Tag.of("errorType", "UNKNOWN");
+	private static final Tag UNKNOWN_ERROR_TYPE = Tag.of("error.type", "UNKNOWN");
 
 	private GraphQlTags() {
 
@@ -59,9 +59,9 @@ public final class GraphQlTags {
 	public static Tag errorType(GraphQLError error) {
 		ErrorClassification errorType = error.getErrorType();
 		if (errorType instanceof ErrorType) {
-			return Tag.of("errorType", ((ErrorType) errorType).name());
+			return Tag.of("error.type", ((ErrorType) errorType).name());
 		}
-		return UNKNOWN_ERRORTYPE;
+		return UNKNOWN_ERROR_TYPE;
 	}
 
 	public static Tag errorPath(GraphQLError error) {
@@ -80,7 +80,7 @@ public final class GraphQlTags {
 				}
 			}
 		}
-		return Tag.of("errorPath", builder.toString());
+		return Tag.of("error.path", builder.toString());
 	}
 
 	public static Tag dataFetchingOutcome(Throwable exception) {

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/startup/StartupTimeMetricsListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -123,7 +123,7 @@ public class StartupTimeMetricsListener implements SmartApplicationListener {
 
 	private Iterable<Tag> createTagsFrom(SpringApplication springApplication) {
 		Class<?> mainClass = springApplication.getMainApplicationClass();
-		return (mainClass != null) ? this.tags.and("main-application-class", mainClass.getName()) : this.tags;
+		return (mainClass != null) ? this.tags.and("main.application.class", mainClass.getName()) : this.tags;
 	}
 
 }

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/web/client/RestTemplateExchangeTags.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -105,17 +105,17 @@ public final class RestTemplateExchangeTags {
 	}
 
 	/**
-	 * Create a {@code clientName} {@code Tag} derived from the {@link URI#getHost host}
+	 * Create a {@code client.name} {@code Tag} derived from the {@link URI#getHost host}
 	 * of the {@link HttpRequest#getURI() URI} of the given {@code request}.
 	 * @param request the request
-	 * @return the clientName tag
+	 * @return the client.name tag
 	 */
 	public static Tag clientName(HttpRequest request) {
 		String host = request.getURI().getHost();
 		if (host == null) {
 			host = "none";
 		}
-		return Tag.of("clientName", host);
+		return Tag.of("client.name", host);
 	}
 
 	/**

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/web/reactive/client/WebClientExchangeTags.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -45,7 +45,7 @@ public final class WebClientExchangeTags {
 
 	private static final Pattern PATTERN_BEFORE_PATH = Pattern.compile("^https?://[^/]+/");
 
-	private static final Tag CLIENT_NAME_NONE = Tag.of("clientName", "none");
+	private static final Tag CLIENT_NAME_NONE = Tag.of("client.name", "none");
 
 	private WebClientExchangeTags() {
 	}
@@ -95,18 +95,18 @@ public final class WebClientExchangeTags {
 	}
 
 	/**
-	 * Create a {@code clientName} {@code Tag} derived from the
+	 * Create a {@code client.name} {@code Tag} derived from the
 	 * {@link java.net.URI#getHost host} of the {@link ClientRequest#url() URL} of the
 	 * given {@code request}.
 	 * @param request the request
-	 * @return the clientName tag
+	 * @return the client.name tag
 	 */
 	public static Tag clientName(ClientRequest request) {
 		String host = request.url().getHost();
 		if (host == null) {
 			return CLIENT_NAME_NONE;
 		}
-		return Tag.of("clientName", host);
+		return Tag.of("client.name", host);
 	}
 
 	/**

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/graphql/GraphQlTagsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -39,21 +39,21 @@ class GraphQlTagsTests {
 	void executionOutcomeShouldSucceed() {
 		ExecutionResult result = ExecutionResultImpl.newExecutionResult().build();
 		Tag outcomeTag = GraphQlTags.executionOutcome(result, null);
-		assertThat(outcomeTag.getValue()).isEqualTo("SUCCESS");
+		assertThat(outcomeTag).isEqualTo(Tag.of("outcome", "SUCCESS"));
 	}
 
 	@Test
 	void executionOutcomeShouldErrorWhenExceptionThrown() {
 		ExecutionResult result = ExecutionResultImpl.newExecutionResult().build();
 		Tag tag = GraphQlTags.executionOutcome(result, new IllegalArgumentException("test error"));
-		assertThat(tag.getValue()).isEqualTo("ERROR");
+		assertThat(tag).isEqualTo(Tag.of("outcome", "ERROR"));
 	}
 
 	@Test
 	void executionOutcomeShouldErrorWhenResponseErrors() {
 		GraphQLError error = GraphqlErrorBuilder.newError().message("Invalid query").build();
 		Tag tag = GraphQlTags.executionOutcome(ExecutionResultImpl.newExecutionResult().addError(error).build(), null);
-		assertThat(tag.getValue()).isEqualTo("ERROR");
+		assertThat(tag).isEqualTo(Tag.of("outcome", "ERROR"));
 	}
 
 	@Test
@@ -61,7 +61,7 @@ class GraphQlTagsTests {
 		GraphQLError error = GraphqlErrorBuilder.newError().errorType(ErrorType.DataFetchingException)
 				.message("test error").build();
 		Tag errorTypeTag = GraphQlTags.errorType(error);
-		assertThat(errorTypeTag.getValue()).isEqualTo("DataFetchingException");
+		assertThat(errorTypeTag).isEqualTo(Tag.of("error.type", "DataFetchingException"));
 	}
 
 	@Test
@@ -69,7 +69,7 @@ class GraphQlTagsTests {
 		GraphQLError error = GraphqlErrorBuilder.newError().path(Arrays.asList("project", "name")).message("test error")
 				.build();
 		Tag errorPathTag = GraphQlTags.errorPath(error);
-		assertThat(errorPathTag.getValue()).isEqualTo("$.project.name");
+		assertThat(errorPathTag).isEqualTo(Tag.of("error.path", "$.project.name"));
 	}
 
 	@Test
@@ -77,19 +77,19 @@ class GraphQlTagsTests {
 		GraphQLError error = GraphqlErrorBuilder.newError().path(Arrays.asList("issues", "42", "title"))
 				.message("test error").build();
 		Tag errorPathTag = GraphQlTags.errorPath(error);
-		assertThat(errorPathTag.getValue()).isEqualTo("$.issues[*].title");
+		assertThat(errorPathTag).isEqualTo(Tag.of("error.path", "$.issues[*].title"));
 	}
 
 	@Test
 	void dataFetchingOutcomeShouldBeSuccessfulIfNoException() {
 		Tag fetchingOutcomeTag = GraphQlTags.dataFetchingOutcome(null);
-		assertThat(fetchingOutcomeTag.getValue()).isEqualTo("SUCCESS");
+		assertThat(fetchingOutcomeTag).isEqualTo(Tag.of("outcome", "SUCCESS"));
 	}
 
 	@Test
 	void dataFetchingOutcomeShouldBeErrorIfException() {
 		Tag fetchingOutcomeTag = GraphQlTags.dataFetchingOutcome(new IllegalStateException("error state"));
-		assertThat(fetchingOutcomeTag.getValue()).isEqualTo("ERROR");
+		assertThat(fetchingOutcomeTag).isEqualTo(Tag.of("outcome", "ERROR"));
 	}
 
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/startup/StartupTimeMetricsListenerTests.java

@@ -118,7 +118,7 @@ class StartupTimeMetricsListenerTests {
 	private void assertMetricExistsWithCustomTagsAndValue(String metricName, Tags expectedCustomTags,
 			Long expectedValueInMillis) {
 		assertThat(this.registry.find(metricName)
-				.tags(Tags.concat(expectedCustomTags, "main-application-class", TestMainApplication.class.getName()))
+				.tags(Tags.concat(expectedCustomTags, "main.application.class", TestMainApplication.class.getName()))
 				.timeGauge()).isNotNull().extracting((m) -> m.value(TimeUnit.MILLISECONDS))
 						.isEqualTo(expectedValueInMillis.doubleValue());
 	}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/client/RestTemplateExchangeTagsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -17,11 +17,13 @@
 package org.springframework.boot.actuate.metrics.web.client;
 
 import java.io.IOException;
+import java.net.URI;
 
 import io.micrometer.core.instrument.Tag;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.http.HttpStatus;
+import org.springframework.http.client.ClientHttpRequest;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.mock.http.client.MockClientHttpResponse;
 
@@ -102,4 +104,12 @@ class RestTemplateExchangeTagsTests {
 		assertThat(tag.getValue()).isEqualTo("UNKNOWN");
 	}
 
+	@Test
+	void clientNameTagIsHostOfRequestUri() throws IOException {
+		ClientHttpRequest request = mock(ClientHttpRequest.class);
+		given(request.getURI()).willReturn(URI.create("https://example.org"));
+		Tag tag = RestTemplateExchangeTags.clientName(request);
+		assertThat(tag).isEqualTo(Tag.of("client.name", "example.org"));
+	}
+
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/reactive/client/DefaultWebClientExchangeTagsProviderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -61,7 +61,7 @@ class DefaultWebClientExchangeTagsProviderTests {
 	void tagsShouldBePopulated() {
 		Iterable<Tag> tags = this.tagsProvider.tags(this.request, this.response, null);
 		assertThat(tags).containsExactlyInAnyOrder(Tag.of("method", "GET"), Tag.of("uri", "/projects/{project}"),
-				Tag.of("clientName", "example.org"), Tag.of("status", "200"), Tag.of("outcome", "SUCCESS"));
+				Tag.of("client.name", "example.org"), Tag.of("status", "200"), Tag.of("outcome", "SUCCESS"));
 	}
 
 	@Test
@@ -70,28 +70,28 @@ class DefaultWebClientExchangeTagsProviderTests {
 				.create(HttpMethod.GET, URI.create("https://example.org/projects/spring-boot")).build();
 		Iterable<Tag> tags = this.tagsProvider.tags(request, this.response, null);
 		assertThat(tags).containsExactlyInAnyOrder(Tag.of("method", "GET"), Tag.of("uri", "/projects/spring-boot"),
-				Tag.of("clientName", "example.org"), Tag.of("status", "200"), Tag.of("outcome", "SUCCESS"));
+				Tag.of("client.name", "example.org"), Tag.of("status", "200"), Tag.of("outcome", "SUCCESS"));
 	}
 
 	@Test
 	void tagsWhenIoExceptionShouldReturnIoErrorStatus() {
 		Iterable<Tag> tags = this.tagsProvider.tags(this.request, null, new IOException());
 		assertThat(tags).containsExactlyInAnyOrder(Tag.of("method", "GET"), Tag.of("uri", "/projects/{project}"),
-				Tag.of("clientName", "example.org"), Tag.of("status", "IO_ERROR"), Tag.of("outcome", "UNKNOWN"));
+				Tag.of("client.name", "example.org"), Tag.of("status", "IO_ERROR"), Tag.of("outcome", "UNKNOWN"));
 	}
 
 	@Test
 	void tagsWhenExceptionShouldReturnClientErrorStatus() {
 		Iterable<Tag> tags = this.tagsProvider.tags(this.request, null, new IllegalArgumentException());
 		assertThat(tags).containsExactlyInAnyOrder(Tag.of("method", "GET"), Tag.of("uri", "/projects/{project}"),
-				Tag.of("clientName", "example.org"), Tag.of("status", "CLIENT_ERROR"), Tag.of("outcome", "UNKNOWN"));
+				Tag.of("client.name", "example.org"), Tag.of("status", "CLIENT_ERROR"), Tag.of("outcome", "UNKNOWN"));
 	}
 
 	@Test
 	void tagsWhenCancelledRequestShouldReturnClientErrorStatus() {
 		Iterable<Tag> tags = this.tagsProvider.tags(this.request, null, null);
 		assertThat(tags).containsExactlyInAnyOrder(Tag.of("method", "GET"), Tag.of("uri", "/projects/{project}"),
-				Tag.of("clientName", "example.org"), Tag.of("status", "CLIENT_ERROR"), Tag.of("outcome", "UNKNOWN"));
+				Tag.of("client.name", "example.org"), Tag.of("status", "CLIENT_ERROR"), Tag.of("outcome", "UNKNOWN"));
 	}
 
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/reactive/client/WebClientExchangeTagsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -88,7 +88,7 @@ class WebClientExchangeTagsTests {
 
 	@Test
 	void clientName() {
-		assertThat(WebClientExchangeTags.clientName(this.request)).isEqualTo(Tag.of("clientName", "example.org"));
+		assertThat(WebClientExchangeTags.clientName(this.request)).isEqualTo(Tag.of("client.name", "example.org"));
 	}
 
 	@Test