Add system properties bridge

instrumentation-api/build.gradle.kts

@@ -22,6 +22,7 @@ dependencies {
   testImplementation("io.opentelemetry.javaagent:opentelemetry-testing-common")
   testImplementation("io.opentelemetry:opentelemetry-sdk-testing")
   testImplementation("io.opentelemetry:opentelemetry-exporter-common")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-incubator")
   testImplementation("org.junit-pioneer:junit-pioneer")
 
   jmhImplementation(project(":instrumentation-api-incubator"))

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/InstrumenterBuilder.java

@@ -49,11 +49,6 @@ public final class InstrumenterBuilder<REQUEST, RESPONSE> {
 
   private static final Logger logger = Logger.getLogger(InstrumenterBuilder.class.getName());
 
-  private static final SpanSuppressionStrategy spanSuppressionStrategy =
-      SpanSuppressionStrategy.fromConfig(
-          ConfigPropertiesUtil.getString(
-              "otel.instrumentation.experimental.span-suppression-strategy"));
-
   final OpenTelemetry openTelemetry;
   final String instrumentationName;
   SpanNameExtractor<? super REQUEST> spanNameExtractor;
@@ -373,8 +368,16 @@ private String getSchemaUrl() {
   }
 
   SpanSuppressor buildSpanSuppressor() {
+    // otel.instrumentation.experimental.* doesn't fit the usual pattern of configuration properties
+    // for instrumentations, so we need to handle both declarative and non-declarative configs here
+    String value =
+        ConfigPropertiesUtil.isDeclarativeConfig(openTelemetry)
+            ? ConfigPropertiesUtil.getString(
+                openTelemetry, "common", "experimental", "span_suppression_strategy")
+            : ConfigPropertiesUtil.getString(
+                "otel.instrumentation.experimental.span-suppression-strategy");
     return new SpanSuppressors.ByContextKey(
-        spanSuppressionStrategy.create(getSpanKeysFromAttributesExtractors()));
+        SpanSuppressionStrategy.fromConfig(value).create(getSpanKeysFromAttributesExtractors()));
   }
 
   private Set<SpanKey> getSpanKeysFromAttributesExtractors() {

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/internal/ConfigPropertiesUtil.java

@@ -5,6 +5,12 @@
 
 package io.opentelemetry.instrumentation.api.internal;
 
+import static io.opentelemetry.api.incubator.config.DeclarativeConfigProperties.empty;
+
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.incubator.ExtendedOpenTelemetry;
+import io.opentelemetry.api.incubator.config.ConfigProvider;
+import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
@@ -17,11 +23,51 @@
  */
 public final class ConfigPropertiesUtil {
 
+  private static final boolean isIncubator = isIncubator();
+
+  private static boolean isIncubator() {
+    try {
+      Class.forName("io.opentelemetry.api.incubator.ExtendedOpenTelemetry");
+      return true;
+    } catch (ClassNotFoundException e) {
+      // The incubator module is not available.
+      // This only happens in OpenTelemetry API instrumentation tests, where an older version of
+      // OpenTelemetry API is used that does not have ExtendedOpenTelemetry.
+      // Having the incubator module without ExtendedOpenTelemetry class should still return false
+      // for those tests to avoid a ClassNotFoundException.
+      return false;
+    }
+  }
+
+  /**
+   * Returns the boolean value of the given property name from system properties and environment
+   * variables.
+   *
+   * <p>It's recommended to use {@link #getBoolean(OpenTelemetry, boolean, String...)} instead to
+   * support Declarative Config.
+   */
   public static boolean getBoolean(String propertyName, boolean defaultValue) {
     String strValue = getString(propertyName);
     return strValue == null ? defaultValue : Boolean.parseBoolean(strValue);
   }
 
+  /**
+   * Returns the boolean value of the given property name from Declarative Config if available,
+   * otherwise falls back to system properties and environment variables.
+   */
+  public static boolean getBoolean(
+      OpenTelemetry openTelemetry, boolean defaultValue, String... propertyName) {
+    DeclarativeConfigProperties node = getDeclarativeConfigNode(openTelemetry, propertyName);
+    if (node != null) {
+      return node.getBoolean(leaf(propertyName), defaultValue);
+    }
+    return getBoolean(toSystemProperty(propertyName), defaultValue);
+  }
+
+  /**
+   * Returns the int value of the given property name from system properties and environment
+   * variables.
+   */
   public static int getInt(String propertyName, int defaultValue) {
     String strValue = getString(propertyName);
     if (strValue == null) {
@@ -34,6 +80,13 @@ public static int getInt(String propertyName, int defaultValue) {
     }
   }
 
+  /**
+   * Returns the string value of the given property name from system properties and environment
+   * variables.
+   *
+   * <p>It's recommended to use {@link #getString(OpenTelemetry, String...)} instead to support
+   * Declarative Config.
+   */
   @Nullable
   public static String getString(String propertyName) {
     String value = System.getProperty(propertyName);
@@ -43,19 +96,54 @@ public static String getString(String propertyName) {
     return System.getenv(toEnvVarName(propertyName));
   }
 
-  public static String getString(String propertyName, String defaultValue) {
-    String strValue = getString(propertyName);
-    return strValue == null ? defaultValue : strValue;
+  /**
+   * Returns the string value of the given property name from Declarative Config if available,
+   * otherwise falls back to system properties and environment variables.
+   */
+  @Nullable
+  public static String getString(OpenTelemetry openTelemetry, String... propertyName) {
+    DeclarativeConfigProperties node = getDeclarativeConfigNode(openTelemetry, propertyName);
+    if (node != null) {
+      return node.getString(leaf(propertyName));
+    }
+    return getString(toSystemProperty(propertyName));
+  }
+
+  /**
+   * Returns the string value of the given property name from Declarative Config if available,
+   * otherwise falls back to system properties and environment variables.
+   */
+  public static String getStringOrFallback(
+      OpenTelemetry openTelemetry, String defaultValue, String... propertyName) {
+    String value = getString(openTelemetry, propertyName);
+    if (value == null) {
+      return defaultValue;
+    }
+    return value;
   }
 
-  public static List<String> getList(String propertyName, List<String> defaultValue) {
-    String value = getString(propertyName);
+  /**
+   * Returns the list of strings value of the given property name from Declarative Config if
+   * available, otherwise falls back to system properties and environment variables.
+   */
+  public static List<String> getList(
+      OpenTelemetry openTelemetry, List<String> defaultValue, String... propertyName) {
+    DeclarativeConfigProperties node = getDeclarativeConfigNode(openTelemetry, propertyName);
+    if (node != null) {
+      return node.getScalarList(leaf(propertyName), String.class, defaultValue);
+    }
+    String value = getString(toSystemProperty(propertyName));
     if (value == null) {
       return defaultValue;
     }
     return filterBlanksAndNulls(value.split(","));
   }
 
+  /** Returns true if the given OpenTelemetry instance supports Declarative Config. */
+  public static boolean isDeclarativeConfig(OpenTelemetry openTelemetry) {
+    return isIncubator && openTelemetry instanceof ExtendedOpenTelemetry;
+  }
+
   private static List<String> filterBlanksAndNulls(String[] values) {
     return Arrays.stream(values)
         .map(String::trim)
@@ -67,5 +155,33 @@ private static String toEnvVarName(String propertyName) {
     return propertyName.toUpperCase(Locale.ROOT).replace('-', '_').replace('.', '_');
   }
 
+  private static String leaf(String[] propertyName) {
+    return propertyName[propertyName.length - 1];
+  }
+
+  @Nullable
+  private static DeclarativeConfigProperties getDeclarativeConfigNode(
+      OpenTelemetry openTelemetry, String... propertyName) {
+    if (isDeclarativeConfig(openTelemetry)) {
+      ExtendedOpenTelemetry extendedOpenTelemetry = (ExtendedOpenTelemetry) openTelemetry;
+      ConfigProvider configProvider = extendedOpenTelemetry.getConfigProvider();
+      DeclarativeConfigProperties instrumentationConfig = configProvider.getInstrumentationConfig();
+      if (instrumentationConfig == null) {
+        return empty();
+      }
+      DeclarativeConfigProperties node = instrumentationConfig.getStructured("java", empty());
+      // last part is the leaf property
+      for (int i = 0; i < propertyName.length - 1; i++) {
+        node = node.getStructured(propertyName[i], empty());
+      }
+      return node;
+    }
+    return null;
+  }
+
+  public static String toSystemProperty(String[] propertyName) {
+    return "otel.instrumentation." + String.join(".", propertyName).replace('_', '-');
+  }
+
   private ConfigPropertiesUtil() {}
 }

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/instrumenter/SpanSuppressionStrategyTest.java

@@ -45,8 +45,7 @@ private static Stream<Arguments> configArgs() {
         Arguments.of("Span-Kind", SpanSuppressionStrategy.SPAN_KIND),
         Arguments.of("semconv", SpanSuppressionStrategy.SEMCONV),
         Arguments.of("SemConv", SpanSuppressionStrategy.SEMCONV),
-        Arguments.of("asdfasdfasdf", SpanSuppressionStrategy.SEMCONV),
-        Arguments.of(null, SpanSuppressionStrategy.SEMCONV));
+        Arguments.of("asdfasdfasdf", SpanSuppressionStrategy.SEMCONV));
   }
 
   @ParameterizedTest