add ComponentLoader to support more auto configuration scenarios (#6217)

buildSrc/src/main/kotlin/otel.japicmp-conventions.gradle.kts

@@ -154,6 +154,8 @@ if (!project.hasProperty("otel.release") && !project.name.startsWith("bom")) {
         // Reproduce defaults from https://github.com/melix/japicmp-gradle-plugin/blob/09f52739ef1fccda6b4310cf3f4b19dc97377024/src/main/java/me/champeau/gradle/japicmp/report/ViolationsGenerator.java#L130
         // with some changes.
         val exclusions = mutableListOf<String>()
+        // Generics are not detected correctly
+        exclusions.add("CLASS_GENERIC_TEMPLATE_CHANGED")
         // Allow new default methods on interfaces
         exclusions.add("METHOD_NEW_DEFAULT")
         // Allow adding default implementations for default methods

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/AutoConfiguredOpenTelemetrySdkBuilder.java

@@ -13,6 +13,7 @@
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
 import io.opentelemetry.sdk.OpenTelemetrySdkBuilder;
+import io.opentelemetry.sdk.autoconfigure.internal.ComponentLoader;
 import io.opentelemetry.sdk.autoconfigure.internal.SpiHelper;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
@@ -102,6 +103,9 @@ public final class AutoConfiguredOpenTelemetrySdkBuilder implements AutoConfigur
   private final List<Function<ConfigProperties, Map<String, String>>> propertiesCustomizers =
       new ArrayList<>();
 
+  private Function<ConfigProperties, ConfigProperties> configPropertiesCustomizer =
+      Function.identity();
+
   private SpiHelper spiHelper =
       SpiHelper.create(AutoConfiguredOpenTelemetrySdk.class.getClassLoader());
 
@@ -253,6 +257,21 @@ public AutoConfiguredOpenTelemetrySdkBuilder addPropertiesCustomizer(
     return this;
   }
 
+  /**
+   * Adds a {@link Function} to invoke the with the {@link ConfigProperties} to allow customization.
+   *
+   * <p>The argument to the function is the {@link ConfigProperties}, with the {@link
+   * #addPropertiesCustomizer(Function)} already applied.
+   *
+   * <p>The return value of the {@link Function} replace the {@link ConfigProperties} to be used.
+   */
+  AutoConfiguredOpenTelemetrySdkBuilder setConfigPropertiesCustomizer(
+      Function<ConfigProperties, ConfigProperties> configPropertiesCustomizer) {
+    requireNonNull(configPropertiesCustomizer, "configPropertiesCustomizer");
+    this.configPropertiesCustomizer = configPropertiesCustomizer;
+    return this;
+  }
+
   /**
    * Adds a {@link BiFunction} to invoke the with the {@link SdkMeterProviderBuilder} to allow
    * customization. The return value of the {@link BiFunction} will replace the passed-in argument.
@@ -385,6 +404,13 @@ public AutoConfiguredOpenTelemetrySdkBuilder setServiceClassLoader(
     return this;
   }
 
+  /** Sets the {@link ComponentLoader} to be used to load SPI implementations. */
+  AutoConfiguredOpenTelemetrySdkBuilder setComponentLoader(ComponentLoader componentLoader) {
+    requireNonNull(componentLoader, "componentLoader");
+    this.spiHelper = SpiHelper.create(componentLoader);
+    return this;
+  }
+
   /**
    * Returns a new {@link AutoConfiguredOpenTelemetrySdk} holding components auto-configured using
    * the settings of this {@link AutoConfiguredOpenTelemetrySdkBuilder}.
@@ -590,7 +616,7 @@ private ConfigProperties computeConfigProperties() {
       Map<String, String> overrides = customizer.apply(properties);
       properties = properties.withOverrides(overrides);
     }
-    return properties;
+    return configPropertiesCustomizer.apply(properties);
   }
 
   // Visible for testing

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/TracerProviderConfiguration.java

@@ -173,21 +173,13 @@ static Sampler configureSampler(String sampler, ConfigProperties config, SpiHelp
       case "always_off":
         return Sampler.alwaysOff();
       case "traceidratio":
-        {
-          double ratio =
-              config.getDouble("otel.traces.sampler.arg", DEFAULT_TRACEIDRATIO_SAMPLE_RATIO);
-          return Sampler.traceIdRatioBased(ratio);
-        }
+        return ratioSampler(config);
       case PARENTBASED_ALWAYS_ON:
         return Sampler.parentBased(Sampler.alwaysOn());
       case "parentbased_always_off":
         return Sampler.parentBased(Sampler.alwaysOff());
       case "parentbased_traceidratio":
-        {
-          double ratio =
-              config.getDouble("otel.traces.sampler.arg", DEFAULT_TRACEIDRATIO_SAMPLE_RATIO);
-          return Sampler.parentBased(Sampler.traceIdRatioBased(ratio));
-        }
+        return Sampler.parentBased(ratioSampler(config));
       case "parentbased_jaeger_remote":
         Sampler jaegerRemote = spiSamplersManager.getByName("jaeger_remote");
         if (jaegerRemote == null) {
@@ -205,5 +197,10 @@ static Sampler configureSampler(String sampler, ConfigProperties config, SpiHelp
     }
   }
 
+  private static Sampler ratioSampler(ConfigProperties config) {
+    double ratio = config.getDouble("otel.traces.sampler.arg", DEFAULT_TRACEIDRATIO_SAMPLE_RATIO);
+    return Sampler.traceIdRatioBased(ratio);
+  }
+
   private TracerProviderConfiguration() {}
 }

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/internal/AutoConfigureUtil.java

@@ -6,9 +6,11 @@
 package io.opentelemetry.sdk.autoconfigure.internal;
 
 import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
+import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdkBuilder;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.function.Function;
 
 /**
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
@@ -30,4 +32,38 @@ public static ConfigProperties getConfig(
           "Error calling getConfig on AutoConfiguredOpenTelemetrySdk", e);
     }
   }
+
+  /** Sets the {@link ComponentLoader} to be used in the auto-configuration process. */
+  public static AutoConfiguredOpenTelemetrySdkBuilder setComponentLoader(
+      AutoConfiguredOpenTelemetrySdkBuilder builder, ComponentLoader componentLoader) {
+    try {
+      Method method =
+          AutoConfiguredOpenTelemetrySdkBuilder.class.getDeclaredMethod(
+              "setComponentLoader", ComponentLoader.class);
+      method.setAccessible(true);
+      method.invoke(builder, componentLoader);
+      return builder;
+    } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
+      throw new IllegalStateException(
+          "Error calling setComponentLoader on AutoConfiguredOpenTelemetrySdkBuilder", e);
+    }
+  }
+
+  /** Sets the {@link ConfigProperties} customizer to be used in the auto-configuration process. */
+  public static AutoConfiguredOpenTelemetrySdkBuilder setConfigPropertiesCustomizer(
+      AutoConfiguredOpenTelemetrySdkBuilder builder,
+      Function<ConfigProperties, ConfigProperties> customizer) {
+    try {
+      Method method =
+          AutoConfiguredOpenTelemetrySdkBuilder.class.getDeclaredMethod(
+              "setConfigPropertiesCustomizer", Function.class);
+      method.setAccessible(true);
+      method.invoke(builder, customizer);
+      return builder;
+    } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
+      throw new IllegalStateException(
+          "Error calling setConfigPropertiesCustomizer on AutoConfiguredOpenTelemetrySdkBuilder",
+          e);
+    }
+  }
 }

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/internal/ComponentLoader.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.autoconfigure.internal;
+
+/**
+ * A loader for components that are discovered via SPI.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+public interface ComponentLoader {
+  /**
+   * Load implementations of an SPI.
+   *
+   * @param spiClass the SPI class
+   * @param <T> the SPI type
+   * @return iterable of SPI implementations
+   */
+  <T> Iterable<T> load(Class<T> spiClass);
+}

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/internal/SpiHelper.java

@@ -27,20 +27,22 @@
  */
 public final class SpiHelper {
 
-  private final ClassLoader classLoader;
-  private final SpiFinder spiFinder;
+  private final ComponentLoader componentLoader;
   private final Set<AutoConfigureListener> listeners =
       Collections.newSetFromMap(new IdentityHashMap<>());
 
-  // Visible for testing
-  SpiHelper(ClassLoader classLoader, SpiFinder spiFinder) {
-    this.classLoader = classLoader;
-    this.spiFinder = spiFinder;
+  private SpiHelper(ComponentLoader componentLoader) {
+    this.componentLoader = componentLoader;
   }
 
   /** Create a {@link SpiHelper} which loads SPIs using the {@code classLoader}. */
   public static SpiHelper create(ClassLoader classLoader) {
-    return new SpiHelper(classLoader, ServiceLoader::load);
+    return new SpiHelper(new ServiceLoaderComponentLoader(classLoader));
+  }
+
+  /** Create a {@link SpiHelper} which loads SPIs using the {@code componentLoader}. */
+  public static SpiHelper create(ComponentLoader componentLoader) {
+    return new SpiHelper(componentLoader);
   }
 
   /**
@@ -96,7 +98,7 @@ public <T extends Ordered> List<T> loadOrdered(Class<T> spiClass) {
    */
   public <T> List<T> load(Class<T> spiClass) {
     List<T> result = new ArrayList<>();
-    for (T service : spiFinder.load(spiClass, classLoader)) {
+    for (T service : componentLoader.load(spiClass)) {
       maybeAddListener(service);
       result.add(service);
     }
@@ -114,8 +116,16 @@ public Set<AutoConfigureListener> getListeners() {
     return Collections.unmodifiableSet(listeners);
   }
 
-  // Visible for testing
-  interface SpiFinder {
-    <T> Iterable<T> load(Class<T> spiClass, ClassLoader classLoader);
+  private static class ServiceLoaderComponentLoader implements ComponentLoader {
+    private final ClassLoader classLoader;
+
+    private ServiceLoaderComponentLoader(ClassLoader classLoader) {
+      this.classLoader = classLoader;
+    }
+
+    @Override
+    public <T> Iterable<T> load(Class<T> spiClass) {
+      return ServiceLoader.load(spiClass, classLoader);
+    }
   }
 }

sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/AutoConfiguredOpenTelemetrySdkTest.java

@@ -20,6 +20,7 @@
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
 
 import io.github.netmikey.logunit.api.LogCapturer;
@@ -36,10 +37,14 @@
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import io.opentelemetry.internal.testing.slf4j.SuppressLogger;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.autoconfigure.internal.AutoConfigureUtil;
+import io.opentelemetry.sdk.autoconfigure.internal.ComponentLoader;
 import io.opentelemetry.sdk.autoconfigure.internal.SpiHelper;
+import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
 import io.opentelemetry.sdk.autoconfigure.spi.internal.AutoConfigureListener;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
 import io.opentelemetry.sdk.common.CompletableResultCode;
 import io.opentelemetry.sdk.logs.LogRecordProcessor;
 import io.opentelemetry.sdk.logs.SdkLoggerProvider;
@@ -315,6 +320,32 @@ void builder_addSpanProcessorCustomizer() {
     verifyNoInteractions(spanExporter1);
   }
 
+  @Test
+  void builder_addAutoConfigurationCustomizerProviderUsingComponentLoader() {
+    AutoConfigurationCustomizerProvider customizerProvider =
+        mock(AutoConfigurationCustomizerProvider.class);
+
+    SpiHelper spiHelper =
+        SpiHelper.create(AutoConfiguredOpenTelemetrySdkBuilder.class.getClassLoader());
+
+    AutoConfigureUtil.setComponentLoader(
+            builder,
+            new ComponentLoader() {
+              @SuppressWarnings("unchecked")
+              @Override
+              public <T> Iterable<T> load(Class<T> spiClass) {
+                if (spiClass.equals(AutoConfigurationCustomizerProvider.class)) {
+                  return Collections.singletonList((T) customizerProvider);
+                }
+                return spiHelper.load(spiClass);
+              }
+            })
+        .build();
+
+    verify(customizerProvider).customize(any());
+    verifyNoMoreInteractions(customizerProvider);
+  }
+
   @Test
   void builder_addPropertiesSupplier() {
     AutoConfiguredOpenTelemetrySdk autoConfigured =
@@ -356,6 +387,23 @@ void builder_addPropertiesCustomizer() {
     assertThat(autoConfigured.getConfig().getString("some.key")).isEqualTo("override-2");
   }
 
+  @Test
+  void builder_setConfigPropertiesCustomizer() {
+    AutoConfiguredOpenTelemetrySdk autoConfigured =
+        AutoConfigureUtil.setConfigPropertiesCustomizer(
+                builder.addPropertiesCustomizer(config -> singletonMap("some-key", "defaultValue")),
+                config -> {
+                  assertThat(config.getString("some-key")).isEqualTo("defaultValue");
+
+                  Map<String, String> map = new HashMap<>(singletonMap("some-key", "override"));
+                  map.putAll(disableExportPropertySupplier().get());
+                  return DefaultConfigProperties.createFromMap(map);
+                })
+            .build();
+
+    assertThat(autoConfigured.getConfig().getString("some.key")).isEqualTo("override");
+  }
+
   @Test
   void builder_addMeterProviderCustomizer() {
     Mockito.lenient().when(metricReader.shutdown()).thenReturn(CompletableResultCode.ofSuccess());