provide experimental base declarative config support (#1089)

SylvainJuge · web-flow · commit 171042dc3de1 · 2026-05-06T14:02:56.000+02:00
* add minimal config for inferred spans

* move span processors order + add baggage opt-in

* fix declarative config

* disable user-agent customization

* test more declarative config

* remove implicit spring args

* remove filter as it's not required

* make config minimal + update test

* add rule-based-sampler config

* fix the rule based sampler default 100% rate

* disable example rules as they don't work as expected

* add changelog

* restore filter until upstream does it by default

* re-enable rule-based examples

* remove user-agent from declarative config

* fix things
diff --git a/custom/src/main/java/co/elastic/otel/declarativeconfig/ElasticDeclarativeConfigurationCustomizer.java b/custom/src/main/java/co/elastic/otel/declarativeconfig/ElasticDeclarativeConfigurationCustomizer.java
@@ -67,7 +67,6 @@ public void customize(DeclarativeConfigurationCustomizer customizer) {
           }
 
           customizeResources(model);
-          customizeUserAgent(model);
           return model;
         });
   }
diff --git a/custom/src/main/resources/co/elastic/otel/config.yaml b/custom/src/main/resources/co/elastic/otel/config.yaml
@@ -31,6 +31,27 @@ propagator:
 
 tracer_provider:
   processors:
+
+    # Add some baggage entries as span attributes, wildcards are supported.
+    # While both included/excluded can be used, we recommend using 'included' to opt-in only for relevant baggage entries.
+    - baggage:
+        included: [ 'example-baggage-key-*' ]
+
+    # Requires the span-stacktrace extension (included in EDOT)
+    # https://github.com/open-telemetry/opentelemetry-java-contrib/tree/main/span-stacktrace
+    - stacktrace/development:
+        # TODO: remove filtering once https://github.com/open-telemetry/opentelemetry-java-contrib/pull/2803 is merged and released
+        filter: co.elastic.otel.SpanStackTraceFilter
+
+    # Requires the inferred-spans extension (included in EDOT)
+    # https://github.com/open-telemetry/opentelemetry-java-contrib/tree/main/inferred-spans
+    - inferred_spans/development:
+        # disabled by default, opt-in
+        enabled: ${OTEL_INFERRED_SPANS_ENABLED:-false}
+        # avoid log messages about missing JVM symbols by default
+        logging_enabled: ${OTEL_INFERRED_SPANS_LOGGING_ENABLED:-false}
+
+    # Batch span exporter, must come last
     - batch:
         exporter:
           # get endpoint from OTEL_EXPORTER_OTLP_ENDPOINT environment variable if set, otherwise fallback to local collector
@@ -42,24 +63,43 @@ tracer_provider:
           # otlp_grpc:
           #  endpoint: ${OTEL_EXPORTER_OTLP_ENDPOINT}
           #  headers_list: ${OTEL_EXPORTER_OTLP_HEADERS}
-    - stacktrace/development:
-        min_duration: 5 # minimal duration in ms, default is 5
-        filter: co.elastic.otel.SpanStackTraceFilter
-  # sampler, parent-based with 100% sampling rate by default
+
+  # Sampler, parent-based with 100% sampling rate by default
   sampler:
-    parent_based:
-      root:
-        # using the consistent sampler implementation
-        probability/development:
-          ratio: 1.0
-      remote_parent_sampled:
-        always_on:
-      remote_parent_not_sampled:
-        always_off:
-      local_parent_sampled:
-        always_on:
-      local_parent_not_sampled:
-        always_off:
+    composite/development:
+      rule_based:
+        rules:
+          # FIXME those examples have an extra 'dummy-work-around' exclusion to avoid issue fixed in
+          # https://github.com/open-telemetry/opentelemetry-java/pull/8356
+          #
+          # filter-out noisy spans from span attributes provided on span start
+          # example 1: filter on user-agent header
+          - attribute_patterns:
+              key: user_agent.original
+              included: [ 'example-noisy-user-agent/*']
+              excluded: [ 'dummy-work-around']
+            sampler:
+              always_off:
+          # example 2: filter on HTTP request path
+          - attribute_patterns:
+              key: url.path
+              included: [ '/healthcheck-to-ignore-*']
+              excluded: [ 'dummy-work-around']
+            sampler:
+              always_off:
+          # example 3: filter on messaging destination
+          - attribute_patterns:
+              key: messaging.destination.name
+              included: [ 'example-noisy-destination/*']
+              excluded: [ 'dummy-work-around']
+            sampler:
+                always_off:
+          # default sampler after rules filtering: parent-based with 100% sampling rate
+          - sampler:
+              parent_threshold:
+                root:
+                  probability:
+                    ratio: 1.0
 
 meter_provider:
   readers:
@@ -79,6 +119,13 @@ meter_provider:
 
 logger_provider:
   processors:
+
+    # Add some baggage entries as log attributes, wildcards are supported
+    # While both included/excluded can be used, we recommend using 'include' to opt-in only for relevant baggage entries.
+    - baggage:
+        included: [ 'example-baggage-key-*' ]
+
+    # Batch log exporter, must come last
     - batch:
         exporter:
           # get endpoint from OTEL_EXPORTER_OTLP_ENDPOINT environment variable if set, otherwise fallback to local collector
diff --git a/custom/src/test/java/co/elastic/otel/declarativeconfig/DefaultDeclarativeConfigTest.java b/custom/src/test/java/co/elastic/otel/declarativeconfig/DefaultDeclarativeConfigTest.java
@@ -25,10 +25,12 @@
 
 import io.opentelemetry.javaagent.tooling.resources.ResourceCustomizerProvider;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfiguration;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.ExperimentalComposableRuleBasedSamplerRuleModel;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.ExperimentalLanguageSpecificInstrumentationModel;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OpenTelemetryConfigurationModel;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SamplerModel;
 import java.io.InputStream;
+import java.util.List;
 import java.util.function.Consumer;
 import net.javacrumbs.jsonunit.assertj.JsonListAssert;
 import org.junit.jupiter.api.Test;
@@ -68,25 +70,35 @@ void testDefaults() {
               json("{\"service\":{}}"),
               json("{\"host\":{}}"));
 
+          // propagators
           assertThat(config.getPropagator()).describedAs("missing propagator").isNotNull();
           assertThatJson(json(config.getPropagator()))
               .inPath("composite")
               .isArray()
               .describedAs("propagators should contain tracecontext and baggage by default")
               .containsExactlyInAnyOrder(json("{\"tracecontext\":{}}"), json("{\"baggage\":{}}"));
 
+          // spans
           assertThat(config.getTracerProvider()).isNotNull();
-          assertThat(config.getTracerProvider().getProcessors()).hasSize(2);
-          assertThatJson(json((config.getTracerProvider().getProcessors().get(0))))
-              .inPath("batch.exporter.otlp_http")
+          assertThat(config.getTracerProvider().getProcessors()).hasSize(4);
+
+          // we don't check baggage configuration, just its presence by default
+          assertThatJson(json(config.getTracerProvider().getProcessors().get(0)))
+              .inPath("baggage")
+              .isObject();
+
+          assertThatJson(json(config.getTracerProvider().getProcessors().get(2)))
+              .inPath("inferred_spans/development")
               .isObject()
-              .containsEntry("endpoint", "http://localhost:4318/v1/traces");
+              .containsEntry("enabled", false) // opt-in, disabled by default
+              .containsEntry("logging_enabled", false); // silent by default
 
-          assertThatJson(json((config.getTracerProvider().getProcessors().get(1))))
-              .inPath("stacktrace/development")
+          assertThatJson(json(config.getTracerProvider().getProcessors().get(3)))
+              .inPath("batch.exporter.otlp_http")
               .isObject()
-              .containsEntry("filter", "co.elastic.otel.SpanStackTraceFilter");
+              .containsEntry("endpoint", "http://localhost:4318/v1/traces");
 
+          // metrics
           assertThat(config.getMeterProvider()).isNotNull();
           assertThat(config.getMeterProvider().getReaders()).hasSize(1);
           assertThatJson(json(config.getMeterProvider().getReaders().get(0)))
@@ -95,32 +107,32 @@ void testDefaults() {
               .containsEntry("endpoint", "http://localhost:4318/v1/metrics")
               .containsEntry("temporality_preference", "delta");
 
+          // logs
           assertThat(config.getLoggerProvider()).isNotNull();
-          assertThat(config.getLoggerProvider().getProcessors()).hasSize(1);
+          assertThat(config.getLoggerProvider().getProcessors()).hasSize(2);
+
+          // we don't check baggage configuration, just its presence by default
           assertThatJson(json((config.getLoggerProvider().getProcessors().get(0))))
+              .inPath("baggage")
+              .isObject();
+
+          assertThatJson(json((config.getLoggerProvider().getProcessors().get(1))))
               .inPath("batch.exporter.otlp_http")
               .isObject()
               .containsEntry("endpoint", "http://localhost:4318/v1/logs");
 
           SamplerModel sampler = config.getTracerProvider().getSampler();
           assertThat(sampler).isNotNull();
 
-          assertThatJson(json(sampler))
-              .inPath("parent_based.root.probability/development.ratio")
+          // we only check that we are using the rule-based sampler and that the default (last)
+          // is the one we expect with 100% sampling
+          assertThatJson(json(sampler)).inPath("composite/development.rule_based.rules").isArray();
+          List<ExperimentalComposableRuleBasedSamplerRuleModel> rules =
+              sampler.getCompositeDevelopment().getRuleBased().getRules();
+          assertThatJson(json(rules.get(rules.size() - 1)))
+              .inPath("sampler.parent_threshold.root.probability.ratio")
               .isNumber()
               .isEqualByComparingTo("1.0");
-          assertThatJson(json(sampler))
-              .inPath("parent_based.remote_parent_sampled.always_on")
-              .isObject();
-          assertThatJson(json(sampler))
-              .inPath("parent_based.remote_parent_not_sampled.always_off")
-              .isObject();
-          assertThatJson(json(sampler))
-              .inPath("parent_based.local_parent_sampled.always_on")
-              .isObject();
-          assertThatJson(json(sampler))
-              .inPath("parent_based.local_parent_not_sampled.always_off")
-              .isObject();
 
           assertThat(config.getInstrumentationDevelopment()).isNotNull();
           ExperimentalLanguageSpecificInstrumentationModel java =
diff --git a/custom/src/test/java/co/elastic/otel/declarativeconfig/ElasticDeclarativeConfigurationCustomizerTest.java b/custom/src/test/java/co/elastic/otel/declarativeconfig/ElasticDeclarativeConfigurationCustomizerTest.java
@@ -23,41 +23,16 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
-import io.opentelemetry.javaagent.tooling.AgentVersion;
 import io.opentelemetry.javaagent.tooling.resources.ResourceCustomizerProvider;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfigurationCustomizer;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfigurationCustomizerProvider;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.BatchLogRecordProcessorModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.BatchSpanProcessorModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.LogRecordExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.LogRecordProcessorModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.LoggerProviderModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.MeterProviderModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.MetricReaderModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.NameStringValuePairModel;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OpenTelemetryConfigurationModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OtlpGrpcExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OtlpGrpcMetricExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OtlpHttpExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OtlpHttpMetricExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.PeriodicMetricReaderModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.PushMetricExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SimpleLogRecordProcessorModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SimpleSpanProcessorModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SpanExporterModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SpanProcessorModel;
-import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.TracerProviderModel;
 import io.opentelemetry.sdk.logs.export.LogRecordExporter;
 import io.opentelemetry.sdk.metrics.export.MetricExporter;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.BiFunction;
 import java.util.function.Function;
-import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
@@ -109,141 +84,6 @@ void distributionResourceProvider(boolean elasticFirst) {
             json("{\"elastic_distribution\":null}]}"));
   }
 
-  @ParameterizedTest
-  @ValueSource(strings = {"grpc", "http"})
-  void userAgent(String protocol) {
-    // setup tracer provider with single + batch exporter
-    // check that the user-agent value is set as expected
-    OpenTelemetryConfigurationModel model = new OpenTelemetryConfigurationModel();
-
-    SpanExporterModel spanExporter = new SpanExporterModel();
-    PushMetricExporterModel metricExporter = new PushMetricExporterModel();
-    LogRecordExporterModel logExporter = new LogRecordExporterModel();
-
-    switch (protocol) {
-      case "grpc":
-        spanExporter.withOtlpGrpc(new OtlpGrpcExporterModel());
-        metricExporter.withOtlpGrpc(new OtlpGrpcMetricExporterModel());
-        logExporter.withOtlpGrpc(new OtlpGrpcExporterModel());
-        break;
-      case "http":
-        spanExporter.withOtlpHttp(new OtlpHttpExporterModel());
-        metricExporter.withOtlpHttp(new OtlpHttpMetricExporterModel());
-        logExporter.withOtlpHttp(new OtlpHttpExporterModel());
-        break;
-      default:
-        throw new IllegalArgumentException("Unsupported protocol: " + protocol);
-    }
-
-    // tracer provider
-    SpanProcessorModel spanSimpleProcessor =
-        new SpanProcessorModel()
-            .withSimple(new SimpleSpanProcessorModel().withExporter(spanExporter));
-    SpanProcessorModel spanBatchProcessor =
-        new SpanProcessorModel()
-            .withBatch(new BatchSpanProcessorModel().withExporter(spanExporter));
-    model.withTracerProvider(
-        new TracerProviderModel()
-            .withProcessors(Arrays.asList(spanSimpleProcessor, spanBatchProcessor)));
-
-    // meter provider
-    model.withMeterProvider(
-        new MeterProviderModel()
-            .withReaders(
-                Collections.singletonList(
-                    new MetricReaderModel()
-                        .withPeriodic(
-                            new PeriodicMetricReaderModel().withExporter(metricExporter)))));
-
-    // logger provider
-    LogRecordProcessorModel logSimpleProcessor =
-        new LogRecordProcessorModel()
-            .withSimple(new SimpleLogRecordProcessorModel().withExporter(logExporter));
-    LogRecordProcessorModel logBatchProcessor =
-        new LogRecordProcessorModel()
-            .withBatch(new BatchLogRecordProcessorModel().withExporter(logExporter));
-    model.withLoggerProvider(
-        new LoggerProviderModel()
-            .withProcessors(Arrays.asList(logSimpleProcessor, logBatchProcessor)));
-
-    model = applyConfigCustomize(model, new ElasticDeclarativeConfigurationCustomizer());
-
-    // tracer provider
-    assertThat(model.getTracerProvider()).isNotNull();
-    assertThatJson(model.getTracerProvider()).inPath("processors").isArray().hasSize(2);
-    for (int i = 0; i < 2; i++) {
-      String pathPrefix = i == 0 ? "simple" : "batch";
-      assertThatJson(model.getTracerProvider().getProcessors().get(i))
-          .inPath(pathPrefix + ".exporter.otlp_" + protocol + ".headers")
-          .isArray()
-          .contains(userAgentHeader("elastic-otlp-" + protocol + "-java/" + AgentVersion.VERSION));
-    }
-
-    // meter provider
-    assertThat(model.getMeterProvider()).isNotNull();
-    assertThatJson(model.getMeterProvider()).inPath("readers").isArray().hasSize(1);
-    assertThatJson(model.getMeterProvider().getReaders().get(0))
-        .inPath("periodic.exporter.otlp_" + protocol + ".headers")
-        .isArray()
-        .contains(userAgentHeader("elastic-otlp-" + protocol + "-java/" + AgentVersion.VERSION));
-
-    // logger provider
-    assertThat(model.getLoggerProvider()).isNotNull();
-    assertThatJson(model.getLoggerProvider()).inPath("processors").isArray().hasSize(2);
-    for (int i = 0; i < 2; i++) {
-      String pathPrefix = i == 0 ? "simple" : "batch";
-      assertThatJson(model.getLoggerProvider().getProcessors().get(i))
-          .inPath(pathPrefix + ".exporter.otlp_" + protocol + ".headers")
-          .isArray()
-          .contains(userAgentHeader("elastic-otlp-" + protocol + "-java/" + AgentVersion.VERSION));
-    }
-  }
-
-  @Test
-  void addUserAgentPriority() {
-    assertThat(ElasticDeclarativeConfigurationCustomizer.addUserAgent(null, null, "my-user-agent"))
-        .describedAs("add user agent when none is present in headers list or headers")
-        .hasSize(1)
-        .flatExtracting("name", "value")
-        .contains("User-Agent", "my-user-agent");
-
-    assertThat(
-            ElasticDeclarativeConfigurationCustomizer.addUserAgent(
-                null, Collections.emptyList(), "my-user-agent"))
-        .describedAs("add user agent when none is present in headers list or headers")
-        .hasSize(1)
-        .flatExtracting("name", "value")
-        .contains("User-Agent", "my-user-agent");
-
-    assertThat(
-            ElasticDeclarativeConfigurationCustomizer.addUserAgent(
-                // using non-standard case is intentional for testing
-                "User-agent=custom-user-agent", null, "my-user-agent"))
-        .describedAs("configured user-agent is preserved")
-        .isNull();
-
-    assertThat(
-            ElasticDeclarativeConfigurationCustomizer.addUserAgent(
-                null,
-                Collections.singletonList(
-                    new NameStringValuePairModel()
-                        .withName("user-agent") // using lower-case is intentional for testing
-                        .withValue("custom-user-Agent")),
-                "my-user-agent"))
-        .describedAs("configured user-agent is preserved")
-        .hasSize(1)
-        .flatExtracting("name", "value")
-        .contains("user-agent", "custom-user-Agent");
-  }
-
-  @NotNull
-  private static Map<String, String> userAgentHeader(String value) {
-    Map<String, String> header = new HashMap<>();
-    header.put("name", "User-Agent");
-    header.put("value", value);
-    return header;
-  }
-
   static OpenTelemetryConfigurationModel applyConfigCustomize(
       OpenTelemetryConfigurationModel originalModel,
       DeclarativeConfigurationCustomizerProvider customizerProvider) {
diff --git a/docs/changelog/1089.yaml b/docs/changelog/1089.yaml

Original file line number	Diff line number	Diff line change
`@@ -67,7 +67,6 @@ public void customize(DeclarativeConfigurationCustomizer customizer) {`
`67`	`67`	`}`
`68`	`68`
`69`	`69`	`customizeResources(model);`
`70`		`- customizeUserAgent(model);`
`71`	`70`	`return model;`
`72`	`71`	`});`
`73`	`72`	`}`