Allow omission of prometheus type & unit from name

Author: psx95

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

@@ -28,6 +28,12 @@ struct PrometheusExporterOptions
 
   // Populating otel_scope_name/otel_scope_labels attributes
   bool without_otel_scope = false;
+
+  // Option to export metrics without the unit suffix
+  bool without_units = false;
+
+  // Option to export metrics without the type suffix
+  bool without_type_suffix = false;
 };
 
 }  // namespace metrics

exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h

@@ -30,12 +30,18 @@ class PrometheusExporterUtils
    * @param populate_target_info whether to populate target_info
    * @param without_otel_scope whether to populate otel_scope_name and otel_scope_version
    * attributes
+   * @param without_units exporter configuration controlling whether to append unit suffix in
+   * the exported metrics.
+   * @param without_type_suffix exporter configuration controlling whether to append type suffix in
+   * the exported metrics.
    * @return a collection of translated metrics that is acceptable by Prometheus
    */
   static std::vector<::prometheus::MetricFamily> TranslateToPrometheus(
       const sdk::metrics::ResourceMetrics &data,
       bool populate_target_info = true,
-      bool without_otel_scope   = false);
+      bool without_otel_scope   = false,
+      bool without_units  = false,
+      bool without_type_suffix  = false);
 
 private:
   /**
@@ -61,7 +67,9 @@ class PrometheusExporterUtils
 
   static std::string MapToPrometheusName(const std::string &name,
                                          const std::string &unit,
-                                         ::prometheus::MetricType prometheus_type);
+                                         ::prometheus::MetricType prometheus_type,
+                                         bool without_units,
+                                         bool without_type_suffix);
 
   /**
    * A utility function that returns the equivalent Prometheus name for the provided OTLP metric

exporters/prometheus/src/exporter_options.cc

@@ -48,10 +48,34 @@ inline bool GetPrometheusPopulateTargetInfo()
   return exists ? setting : true;
 }
 
+inline bool GetPrometheusWithoutUnits()
+{
+  constexpr char kPrometheusWithoutUnits[] =
+      "OTEL_CPP_PROMETHEUS_EXPORTER_WITHOUT_UNITS";
+  bool setting;
+  const auto exists =
+      opentelemetry::sdk::common::GetBoolEnvironmentVariable(kPrometheusWithoutUnits, setting);
+
+  return exists ? setting : false;
+}
+
+inline bool GetPrometheusWithoutTypeSuffix()
+{
+  constexpr char kPrometheusWithoutTypeSuffix[] =
+      "OTEL_CPP_PROMETHEUS_EXPORTER_WITHOUT_TYPE_SUFFIX";
+  bool setting;
+  const auto exists =
+      opentelemetry::sdk::common::GetBoolEnvironmentVariable(kPrometheusWithoutTypeSuffix, setting);
+
+  return exists ? setting : false;
+}
+
 PrometheusExporterOptions::PrometheusExporterOptions()
     : url(GetPrometheusDefaultHttpEndpoint()),
       populate_target_info(GetPrometheusPopulateTargetInfo()),
-      without_otel_scope(GetPrometheusWithoutOtelScope())
+      without_otel_scope(GetPrometheusWithoutOtelScope()),
+      without_units(GetPrometheusWithoutUnits()),
+      without_type_suffix(GetPrometheusWithoutTypeSuffix())
 {}
 
 }  // namespace metrics

exporters/prometheus/src/exporter_utils.cc

@@ -102,13 +102,15 @@ std::string SanitizeLabel(std::string label_key)
  * Helper function to convert OpenTelemetry metrics data collection
  * to Prometheus metrics data collection
  *
- * @param records a collection of metrics in OpenTelemetry
+ * @param data a collection of metrics in OpenTelemetry
  * @return a collection of translated metrics that is acceptable by Prometheus
  */
 std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateToPrometheus(
     const sdk::metrics::ResourceMetrics &data,
     bool populate_target_info,
-    bool without_otel_scope)
+    bool without_otel_scope,
+    bool without_units,
+    bool without_type_suffix)
 {
 
   // initialize output vector
@@ -150,7 +152,9 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
       }
       const prometheus_client::MetricType type = TranslateType(kind, is_monotonic);
       metric_family.name = MapToPrometheusName(metric_data.instrument_descriptor.name_,
-                                               metric_data.instrument_descriptor.unit_, type);
+                                               metric_data.instrument_descriptor.unit_, type,
+                                               without_units, without_type_suffix);
+      // TODO (psx95): Add tests to check compliance
       metric_family.type = type;
       const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope =
           without_otel_scope ? nullptr : instrumentation_info.scope_;
@@ -492,10 +496,19 @@ std::string PrometheusExporterUtils::CleanUpString(const std::string &str)
 std::string PrometheusExporterUtils::MapToPrometheusName(
     const std::string &name,
     const std::string &unit,
-    prometheus_client::MetricType prometheus_type)
+    prometheus_client::MetricType prometheus_type,
+    bool without_units,
+    bool without_type_suffix)
 {
   auto sanitized_name                    = SanitizeNames(name);
-  std::string prometheus_equivalent_unit = GetEquivalentPrometheusUnit(unit);
+  std::string prometheus_equivalent_unit;
+  if (without_units)
+  {
+    prometheus_equivalent_unit = "";
+  } else
+  {
+    prometheus_equivalent_unit = GetEquivalentPrometheusUnit(unit);
+  }
 
   // Append prometheus unit if not null or empty.
   if (!prometheus_equivalent_unit.empty() &&
@@ -505,7 +518,7 @@ std::string PrometheusExporterUtils::MapToPrometheusName(
   }
 
   // Special case - counter
-  if (prometheus_type == prometheus_client::MetricType::Counter)
+  if (prometheus_type == prometheus_client::MetricType::Counter && !without_type_suffix)
   {
     auto t_pos           = sanitized_name.rfind("_total");
     bool ends_with_total = t_pos == sanitized_name.size() - 6;
@@ -517,7 +530,7 @@ std::string PrometheusExporterUtils::MapToPrometheusName(
 
   // Special case - gauge
   if (unit == "1" && prometheus_type == prometheus_client::MetricType::Gauge &&
-      sanitized_name.find("ratio") == std::string::npos)
+      sanitized_name.find("ratio") == std::string::npos && !without_type_suffix)
   {
     sanitized_name += "_ratio";
   }

exporters/prometheus/test/exporter_utils_test.cc

@@ -56,7 +56,7 @@ class SanitizeNameTester
                                          const std::string &unit,
                                          prometheus_client::MetricType prometheus_type)
   {
-    return PrometheusExporterUtils::MapToPrometheusName(name, unit, prometheus_type);
+    return PrometheusExporterUtils::MapToPrometheusName(name, unit, prometheus_type, false, false);
   }
 };
 }  // namespace metrics