opentelemetrytracer: Added support to configure a Dynatrace sampler

api/envoy/extensions/tracers/opentelemetry/samplers/v3/BUILD

@@ -5,5 +5,8 @@ load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
 licenses(["notice"])  # Apache 2
 
 api_proto_package(
-    deps = ["@com_github_cncf_xds//udpa/annotations:pkg"],
+    deps = [
+        "//envoy/config/core/v3:pkg",
+        "@com_github_cncf_xds//udpa/annotations:pkg",
+    ],
 )

api/envoy/extensions/tracers/opentelemetry/samplers/v3/dynatrace_sampler.proto

@@ -0,0 +1,53 @@
+syntax = "proto3";
+
+package envoy.extensions.tracers.opentelemetry.samplers.v3;
+
+import "envoy/config/core/v3/http_uri.proto";
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.tracers.opentelemetry.samplers.v3";
+option java_outer_classname = "DynatraceSamplerProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/tracers/opentelemetry/samplers/v3;samplersv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Dynatrace Sampler config]
+// Configuration for the Dynatrace Sampler extension.
+// [#extension: envoy.tracers.opentelemetry.samplers.dynatrace]
+
+// [#next-free-field: 6]
+message DynatraceSamplerConfig {
+  // The Dynatrace tenant.
+  //
+  // The value can be obtained from the Envoy deployment page in Dynatrace.
+  string tenant = 1;
+
+  // The id of the Dynatrace cluster id.
+  //
+  // The value can be obtained from the Envoy deployment page in Dynatrace.
+  int32 cluster_id = 2;
+
+  // The HTTP URI to fetch the sampler configuration (root spans per minute). For example:
+  //
+  // .. code-block:: yaml
+  //
+  //    http_uri:
+  //      uri: <tenant>.dev.dynatracelabs.com/api/v2/otlp/v1/traces
+  //      cluster: dynatrace
+  //      timeout: 10s
+  //
+  config.core.v3.HttpUri http_uri = 3;
+
+  // The access token to fetch the sampling configuration from the Dynatrace API
+  string token = 4;
+
+  // Default number of root spans per minute, used when the value can't be obtained from the Dynatrace API.
+  //
+  // A default value of ``1000`` is used when:
+  //
+  // - ``root_spans_per_minute`` is unset
+  // - ``root_spans_per_minute`` is set to 0
+  //
+  uint32 root_spans_per_minute = 5;
+}

bazel/repository_locations.bzl

@@ -565,6 +565,7 @@ REPOSITORY_LOCATIONS_SPEC = dict(
         extensions = [
             "envoy.tracers.opentelemetry",
             "envoy.tracers.opentelemetry.samplers.always_on",
+            "envoy.tracers.opentelemetry.samplers.dynatrace",
         ],
         release_date = "2024-02-17",
         cpe = "N/A",

changelogs/current.yaml

@@ -227,6 +227,9 @@ new_features:
     added a :ref:`configuration option
     <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.append_local_overload>` to add
     ``x-envoy-local-overloaded`` header when Overload Manager is triggered.
+- area: tracing
+  change: |
+    Added support to configure a Dynatrace sampler for the OpenTelemetry tracer.
 
 deprecated:
 - area: listener

source/extensions/extensions_build_config.bzl

@@ -279,6 +279,7 @@ EXTENSIONS = {
     #
 
     "envoy.tracers.opentelemetry.samplers.always_on":         "//source/extensions/tracers/opentelemetry/samplers/always_on:config",
+    "envoy.tracers.opentelemetry.samplers.dynatrace":         "//source/extensions/tracers/opentelemetry/samplers/dynatrace:config",
 
     #
     # Transport sockets

source/extensions/extensions_metadata.yaml

@@ -1180,6 +1180,13 @@ envoy.tracers.opentelemetry.samplers.always_on:
   status: wip
   type_urls:
   - envoy.extensions.tracers.opentelemetry.samplers.v3.AlwaysOnSamplerConfig
+envoy.tracers.opentelemetry.samplers.dynatrace:
+  categories:
+  - envoy.tracers.opentelemetry.samplers
+  security_posture: unknown
+  status: wip
+  type_urls:
+  - envoy.extensions.tracers.opentelemetry.samplers.v3.DynatraceSamplerConfig
 envoy.tracers.skywalking:
   categories:
   - envoy.tracers

source/extensions/tracers/opentelemetry/samplers/dynatrace/BUILD

@@ -0,0 +1,46 @@
+load(
+    "//bazel:envoy_build_system.bzl",
+    "envoy_cc_extension",
+    "envoy_cc_library",
+    "envoy_extension_package",
+)
+
+licenses(["notice"])  # Apache 2
+
+envoy_extension_package()
+
+envoy_cc_extension(
+    name = "config",
+    srcs = ["config.cc"],
+    hdrs = ["config.h"],
+    deps = [
+        ":dynatrace_sampler_lib",
+        "//envoy/registry",
+        "//source/common/config:utility_lib",
+        "@envoy_api//envoy/extensions/tracers/opentelemetry/samplers/v3:pkg_cc_proto",
+    ],
+)
+
+envoy_cc_library(
+    name = "dynatrace_sampler_lib",
+    srcs = [
+        "dynatrace_sampler.cc",
+        "sampler_config.cc",
+        "sampler_config_provider.cc",
+        "sampling_controller.cc",
+    ],
+    hdrs = [
+        "dynatrace_sampler.h",
+        "sampler_config.h",
+        "sampler_config_provider.h",
+        "sampling_controller.h",
+        "stream_summary.h",
+        "tenant_id.h",
+    ],
+    deps = [
+        "//source/common/config:datasource_lib",
+        "//source/extensions/tracers/opentelemetry:opentelemetry_tracer_lib",
+        "//source/extensions/tracers/opentelemetry/samplers:sampler_lib",
+        "@envoy_api//envoy/extensions/tracers/opentelemetry/samplers/v3:pkg_cc_proto",
+    ],
+)

source/extensions/tracers/opentelemetry/samplers/dynatrace/config.cc

@@ -0,0 +1,38 @@
+#include "source/extensions/tracers/opentelemetry/samplers/dynatrace/config.h"
+
+#include <memory>
+
+#include "envoy/extensions/tracers/opentelemetry/samplers/v3/dynatrace_sampler.pb.validate.h"
+
+#include "source/common/config/utility.h"
+#include "source/common/protobuf/utility.h"
+#include "source/extensions/tracers/opentelemetry/samplers/dynatrace/dynatrace_sampler.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Tracers {
+namespace OpenTelemetry {
+
+SamplerSharedPtr
+DynatraceSamplerFactory::createSampler(const Protobuf::Message& config,
+                                       Server::Configuration::TracerFactoryContext& context) {
+  auto mptr = Envoy::Config::Utility::translateAnyToFactoryConfig(
+      dynamic_cast<const ProtobufWkt::Any&>(config), context.messageValidationVisitor(), *this);
+
+  const auto& proto_config = MessageUtil::downcastAndValidate<
+      const envoy::extensions::tracers::opentelemetry::samplers::v3::DynatraceSamplerConfig&>(
+      *mptr, context.messageValidationVisitor());
+
+  SamplerConfigProviderPtr cf = std::make_unique<SamplerConfigProviderImpl>(context, proto_config);
+  return std::make_shared<DynatraceSampler>(proto_config, context, std::move(cf));
+}
+
+/**
+ * Static registration for the Dynatrace sampler factory. @see RegisterFactory.
+ */
+REGISTER_FACTORY(DynatraceSamplerFactory, SamplerFactory);
+
+} // namespace OpenTelemetry
+} // namespace Tracers
+} // namespace Extensions
+} // namespace Envoy

source/extensions/tracers/opentelemetry/samplers/dynatrace/config.h

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <string>
+
+#include "envoy/extensions/tracers/opentelemetry/samplers/v3/dynatrace_sampler.pb.h"
+#include "envoy/registry/registry.h"
+
+#include "source/extensions/tracers/opentelemetry/samplers/sampler.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Tracers {
+namespace OpenTelemetry {
+
+/**
+ * Config registration for the DynatraceSampler. @see SamplerFactory.
+ */
+class DynatraceSamplerFactory : public SamplerFactory {
+public:
+  /**
+   * @brief Creates a Dynatrace sampler
+   *
+   * @param config The sampler configuration
+   * @param context The tracer factory context.
+   * @return SamplerSharedPtr
+   */
+  SamplerSharedPtr createSampler(const Protobuf::Message& config,
+                                 Server::Configuration::TracerFactoryContext& context) override;
+
+  ProtobufTypes::MessagePtr createEmptyConfigProto() override {
+    return std::make_unique<
+        envoy::extensions::tracers::opentelemetry::samplers::v3::DynatraceSamplerConfig>();
+  }
+  std::string name() const override { return "envoy.tracers.opentelemetry.samplers.dynatrace"; }
+};
+
+DECLARE_FACTORY(DynatraceSamplerFactory);
+
+} // namespace OpenTelemetry
+} // namespace Tracers
+} // namespace Extensions
+} // namespace Envoy