[CONFIGURATION] File configuration - prometheus exporter builder

exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_options.h

@@ -18,8 +18,12 @@ namespace metrics
  */
 struct PrometheusExporterOptions
 {
+  // Lookup environment variables
   PrometheusExporterOptions();
 
+  // No defaults
+  PrometheusExporterOptions(void *);
+
   // The endpoint the Prometheus backend can collect metrics from
   std::string url;
 

exporters/prometheus/include/opentelemetry/exporters/prometheus/prometheus_pull_builder.h

@@ -0,0 +1,33 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include <memory>
+
+#include "opentelemetry/sdk/configuration/prometheus_pull_metric_exporter_builder.h"
+#include "opentelemetry/sdk/configuration/prometheus_pull_metric_exporter_configuration.h"
+#include "opentelemetry/sdk/configuration/registry.h"
+#include "opentelemetry/sdk/metrics/metric_reader.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace exporter
+{
+namespace metrics
+{
+
+class OPENTELEMETRY_EXPORT PrometheusPullBuilder
+    : public opentelemetry::sdk::configuration::PrometheusPullMetricExporterBuilder
+{
+public:
+  static void Register(opentelemetry::sdk::configuration::Registry *registry);
+
+  std::unique_ptr<opentelemetry::sdk::metrics::MetricReader> Build(
+      const opentelemetry::sdk::configuration::PrometheusPullMetricExporterConfiguration *model)
+      const override;
+};
+
+}  // namespace metrics
+}  // namespace exporter
+OPENTELEMETRY_END_NAMESPACE

exporters/prometheus/src/exporter_options.cc

@@ -77,6 +77,8 @@ PrometheusExporterOptions::PrometheusExporterOptions()
       without_type_suffix(GetPrometheusWithoutTypeSuffix())
 {}
 
+PrometheusExporterOptions::PrometheusExporterOptions(void *) : url("") {}
+
 }  // namespace metrics
 }  // namespace exporter
 OPENTELEMETRY_END_NAMESPACE

exporters/prometheus/src/prometheus_pull_builder.cc

@@ -0,0 +1,49 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "opentelemetry/exporters/prometheus/exporter_factory.h"
+#include "opentelemetry/exporters/prometheus/exporter_options.h"
+#include "opentelemetry/exporters/prometheus/prometheus_pull_builder.h"
+#include "opentelemetry/sdk/configuration/prometheus_pull_metric_exporter_builder.h"
+#include "opentelemetry/sdk/configuration/prometheus_pull_metric_exporter_configuration.h"
+#include "opentelemetry/sdk/configuration/registry.h"
+#include "opentelemetry/sdk/metrics/metric_reader.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace exporter
+{
+namespace metrics
+{
+
+void PrometheusPullBuilder::Register(opentelemetry::sdk::configuration::Registry *registry)
+{
+  auto builder = std::make_unique<PrometheusPullBuilder>();
+  registry->SetPrometheusPullMetricExporterBuilder(std::move(builder));
+}
+
+std::unique_ptr<opentelemetry::sdk::metrics::MetricReader> PrometheusPullBuilder::Build(
+    const opentelemetry::sdk::configuration::PrometheusPullMetricExporterConfiguration *model) const
+{
+  opentelemetry::exporter::metrics::PrometheusExporterOptions options(nullptr);
+
+  std::string url(model->host);
+  url.append(":");
+  url.append(std::to_string(model->port));
+
+  options.url                  = url;
+  options.populate_target_info = true;
+  options.without_otel_scope   = model->without_scope_info;
+  options.without_units        = model->without_units;
+  options.without_type_suffix  = model->without_type_suffix;
+
+  return PrometheusExporterFactory::Create(options);
+}
+
+}  // namespace metrics
+}  // namespace exporter
+OPENTELEMETRY_END_NAMESPACE