Merge pull request #44493 from izeye

* pr/44493:
  Polish "Remove default value for OtlpMetricsProperties.url"
  Remove default value for OtlpMetricsProperties.url

Closes gh-44493

Author: mhalbritter

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpMetricsProperties.java

@@ -39,7 +39,7 @@ public class OtlpMetricsProperties extends StepRegistryProperties {
 	/**
 	 * URI of the OTLP server.
 	 */
-	private String url = "http://localhost:4318/v1/metrics";
+	private String url;
 
 	/**
 	 * Aggregation temporality of sums. It defines the way additive values are expressed.

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

@@ -29,6 +29,8 @@
 import org.springframework.mock.env.MockEnvironment;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.spy;
 
 /**
  * Tests for {@link OtlpMetricsPropertiesConfigAdapter}.
@@ -54,6 +56,20 @@ void setUp() {
 		this.connectionDetails = new PropertiesOtlpMetricsConnectionDetails(this.properties);
 	}
 
+	@Test
+	void whenPropertiesUrlIsNotSetAdapterUrlReturnsDefault() {
+		assertThat(this.properties.getUrl()).isNull();
+		assertThat(createAdapter().url()).isEqualTo("http://localhost:4318/v1/metrics");
+	}
+
+	@Test
+	void whenPropertiesUrlIsNotSetThanUseOtlpConfigUrlAsFallback() {
+		assertThat(this.properties.getUrl()).isNull();
+		OtlpMetricsPropertiesConfigAdapter adapter = spy(createAdapter());
+		given(adapter.get("management.otlp.metrics.export.url")).willReturn("https://my-endpoint/v1/metrics");
+		assertThat(adapter.url()).isEqualTo("https://my-endpoint/v1/metrics");
+	}
+
 	@Test
 	void whenPropertiesUrlIsSetAdapterUrlReturnsIt() {
 		this.properties.setUrl("http://another-url:4318/v1/metrics");

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

@@ -35,7 +35,6 @@ void defaultValuesAreConsistent() {
 		OtlpMetricsProperties properties = new OtlpMetricsProperties();
 		OtlpConfig config = OtlpConfig.DEFAULT;
 		assertStepRegistryDefaultValues(properties, config);
-		assertThat(properties.getUrl()).isEqualTo(config.url());
 		assertThat(properties.getAggregationTemporality()).isSameAs(config.aggregationTemporality());
 		assertThat(properties.getHistogramFlavor()).isSameAs(config.histogramFlavor());
 		assertThat(properties.getMaxScale()).isEqualTo(config.maxScale());