Add RuleBasedRoutingSampler SPI implementation

Author: jack-berg

samplers/build.gradle.kts

@@ -7,8 +7,9 @@ description = "Sampler which makes its decision based on semantic attributes val
 otelJava.moduleName.set("io.opentelemetry.contrib.sampler")
 
 dependencies {
-  api("io.opentelemetry:opentelemetry-sdk")
+  api("io.opentelemetry:opentelemetry-sdk:1.31.0-SNAPSHOT")
   api("io.opentelemetry.semconv:opentelemetry-semconv")
-  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
-  api("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure:1.31.0-SNAPSHOT")
+  api("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi:1.31.0-SNAPSHOT")
+  implementation("io.opentelemetry:opentelemetry-sdk-extension-incubator:1.31.0-alpha-SNAPSHOT")
 }

samplers/src/main/java/io/opentelemetry/contrib/sampler/RuleBasedRoutingSamplerProvider.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.sampler;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.trace.SpanKind;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
+import io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSamplerProvider;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.ExtendedConfigProperties;
+import io.opentelemetry.sdk.trace.samplers.Sampler;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+public class RuleBasedRoutingSamplerProvider implements ConfigurableSamplerProvider {
+
+  @Override
+  public Sampler createSampler(ConfigProperties config) {
+    if (!(config instanceof ExtendedConfigProperties)) {
+      throw new ConfigurationException("Only support with file configuration");
+    }
+
+    String fallbackSamplerString = config.getString("fallback", "always_on");
+    Sampler fallbackSampler;
+    if (fallbackSamplerString.equals("always_on")) {
+      fallbackSampler = Sampler.alwaysOn();
+    } else if (fallbackSamplerString.equals("always_off")) {
+      fallbackSampler = Sampler.alwaysOff();
+    } else {
+      throw new IllegalArgumentException("fallback must be always_on or always_off");
+    }
+
+    String spanKindString = config.getString("span_kind", "SERVER");
+    SpanKind spanKind;
+    try {
+      spanKind = SpanKind.valueOf(config.getString("span_kind", "SERVER"));
+    } catch (NoSuchElementException e) {
+      throw new ConfigurationException("Invalid span_kind: " + spanKindString, e);
+    }
+
+    RuleBasedRoutingSamplerBuilder builder =
+        RuleBasedRoutingSampler.builder(spanKind, fallbackSampler);
+
+    List<ExtendedConfigProperties> rules =
+        ((ExtendedConfigProperties) config).getListConfigProperties("drop_rules");
+    if (rules == null || rules.isEmpty()) {
+      throw new ConfigurationException("drop_rules is required");
+    }
+    for (ExtendedConfigProperties rule : rules) {
+      String attribute = rule.getString("attribute");
+      String pattern = rule.getString("pattern");
+      if (attribute == null || pattern == null) {
+        throw new ConfigurationException("drop_rule entries require attribute and pattern fields");
+      }
+      builder.drop(AttributeKey.stringKey(attribute), pattern);
+    }
+
+    return builder.build();
+  }
+
+  @Override
+  public String getName() {
+    return "rule_based_routing_sampler";
+  }
+}

samplers/src/main/resources/META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSamplerProvider

@@ -1 +1,2 @@
 io.opentelemetry.contrib.sampler.LinksParentAlwaysOnSamplerProvider
+io.opentelemetry.contrib.sampler.RuleBasedRoutingSamplerProvider

settings.gradle.kts

@@ -12,6 +12,7 @@ plugins {
 
 dependencyResolutionManagement {
   repositories {
+    mavenLocal()
     mavenCentral()
   }
 }