feat(exporter-prometheus): add additional attributes option (#5317)

Co-authored-by: Marc Pichler <[email protected]>

experimental/CHANGELOG.md

@@ -22,6 +22,8 @@ All notable changes to experimental packages in this project will be documented
 * feat(instrumentation-fetch): add a `requestHook` option [#5380](https://github.com/open-telemetry/opentelemetry-js/pull/5380)
 * feat(instrumentation): re-export initialize function from import-in-the-middle [#5123](https://github.com/open-telemetry/opentelemetry-js/pull/5123)
 * feat(sdk-node): lower diagnostic level [#5360](https://github.com/open-telemetry/opentelemetry-js/pull/5360) @cjihrig
+* feat(exporter-prometheus): add additional attributes option [#5317](https://github.com/open-telemetry/opentelemetry-js/pull/5317) @marius-a-mueller
+  * Add `withResourceConstantLabels` option to `ExporterConfig`. It can be used to define a regex pattern to choose which resource attributes will be used as static labels on the metrics. The default is to not set any static labels.
 
 ### :bug: (Bug Fix)
 

experimental/packages/opentelemetry-exporter-prometheus/src/PrometheusExporter.ts

@@ -34,6 +34,7 @@ export class PrometheusExporter extends MetricReader {
     endpoint: '/metrics',
     prefix: '',
     appendTimestamp: false,
+    withResourceConstantLabels: undefined,
   };
 
   private readonly _host?: string;
@@ -82,11 +83,15 @@ export class PrometheusExporter extends MetricReader {
       typeof config.appendTimestamp === 'boolean'
         ? config.appendTimestamp
         : PrometheusExporter.DEFAULT_OPTIONS.appendTimestamp;
+    const _withResourceConstantLabels =
+      config.withResourceConstantLabels ||
+      PrometheusExporter.DEFAULT_OPTIONS.withResourceConstantLabels;
     // unref to prevent prometheus exporter from holding the process open on exit
     this._server = createServer(this._requestHandler).unref();
     this._serializer = new PrometheusSerializer(
       this._prefix,
-      this._appendTimestamp
+      this._appendTimestamp,
+      _withResourceConstantLabels
     );
 
     this._baseUrl = `http://${this._host}:${this._port}/`;

experimental/packages/opentelemetry-exporter-prometheus/src/PrometheusSerializer.ts

@@ -171,17 +171,29 @@ const NO_REGISTERED_METRICS = '# no registered metrics';
 export class PrometheusSerializer {
   private _prefix: string | undefined;
   private _appendTimestamp: boolean;
+  private _additionalAttributes: Attributes | undefined;
+  private _withResourceConstantLabels: RegExp | undefined;
 
-  constructor(prefix?: string, appendTimestamp = false) {
+  constructor(
+    prefix?: string,
+    appendTimestamp = false,
+    withResourceConstantLabels?: RegExp
+  ) {
     if (prefix) {
       this._prefix = prefix + '_';
     }
     this._appendTimestamp = appendTimestamp;
+    this._withResourceConstantLabels = withResourceConstantLabels;
   }
 
   serialize(resourceMetrics: ResourceMetrics): string {
     let str = '';
 
+    this._additionalAttributes = this._filterResourceConstantLabels(
+      resourceMetrics.resource.attributes,
+      this._withResourceConstantLabels
+    );
+
     for (const scopeMetrics of resourceMetrics.scopeMetrics) {
       str += this._serializeScopeMetrics(scopeMetrics);
     }
@@ -193,6 +205,22 @@ export class PrometheusSerializer {
     return this._serializeResource(resourceMetrics.resource) + str;
   }
 
+  private _filterResourceConstantLabels(
+    attributes: Attributes,
+    pattern: RegExp | undefined
+  ) {
+    if (pattern) {
+      const filteredAttributes: Attributes = {};
+      for (const [key, value] of Object.entries(attributes)) {
+        if (key.match(pattern)) {
+          filteredAttributes[key] = value;
+        }
+      }
+      return filteredAttributes;
+    }
+    return;
+  }
+
   private _serializeScopeMetrics(scopeMetrics: ScopeMetrics) {
     let str = '';
     for (const metric of scopeMetrics.metrics) {
@@ -260,7 +288,7 @@ export class PrometheusSerializer {
       attributes,
       value,
       this._appendTimestamp ? timestamp : undefined,
-      undefined
+      this._additionalAttributes
     );
     return results;
   }
@@ -285,7 +313,7 @@ export class PrometheusSerializer {
           attributes,
           value,
           this._appendTimestamp ? timestamp : undefined,
-          undefined
+          this._additionalAttributes
         );
     }
 
@@ -312,12 +340,12 @@ export class PrometheusSerializer {
         attributes,
         cumulativeSum,
         this._appendTimestamp ? timestamp : undefined,
-        {
+        Object.assign({}, this._additionalAttributes ?? {}, {
           le:
             upperBound === undefined || upperBound === Infinity
               ? '+Inf'
               : String(upperBound),
-        }
+        })
       );
     }
 

experimental/packages/opentelemetry-exporter-prometheus/src/export/types.ts

@@ -66,4 +66,12 @@ export interface ExporterConfig {
    * @experimental
    */
   metricProducers?: MetricProducer[];
+
+  /**
+   * Regex pattern for defining which resource attributes will be applied
+   * as constant labels to the metrics.
+   * e.g. 'telemetry_.+' for all attributes starting with 'telemetry'.
+   * @default undefined (no resource attributes are applied)
+   */
+  withResourceConstantLabels?: RegExp;
 }

experimental/packages/opentelemetry-exporter-prometheus/test/PrometheusExporter.test.ts

@@ -553,6 +553,40 @@ describe('PrometheusExporter', () => {
         '',
       ]);
     });
+
+    it('should export a metric with all resource attributes', async () => {
+      exporter = new PrometheusExporter({
+        withResourceConstantLabels: /.*/,
+      });
+      setup(exporter);
+      const body = await request('http://localhost:9464/metrics');
+      const lines = body.split('\n');
+
+      assert.deepStrictEqual(lines, [
+        ...serializedDefaultResourceLines,
+        '# HELP counter_total description missing',
+        '# TYPE counter_total counter',
+        `counter_total{key1="attributeValue1",service_name="${serviceName}",telemetry_sdk_language="${sdkLanguage}",telemetry_sdk_name="${sdkName}",telemetry_sdk_version="${sdkVersion}"} 10`,
+        '',
+      ]);
+    });
+
+    it('should export a metric with two resource attributes', async () => {
+      exporter = new PrometheusExporter({
+        withResourceConstantLabels: /telemetry.sdk.language|telemetry.sdk.name/,
+      });
+      setup(exporter);
+      const body = await request('http://localhost:9464/metrics');
+      const lines = body.split('\n');
+
+      assert.deepStrictEqual(lines, [
+        ...serializedDefaultResourceLines,
+        '# HELP counter_total description missing',
+        '# TYPE counter_total counter',
+        `counter_total{key1="attributeValue1",telemetry_sdk_language="${sdkLanguage}",telemetry_sdk_name="${sdkName}"} 10`,
+        '',
+      ]);
+    });
   });
 });
 

experimental/packages/opentelemetry-exporter-prometheus/test/PrometheusSerializer.test.ts

@@ -42,10 +42,12 @@ const attributes = {
   foo2: 'bar2',
 };
 
+const resourceAttributes = `service_name="${serviceName}",telemetry_sdk_language="${sdkLanguage}",telemetry_sdk_name="${sdkName}",telemetry_sdk_version="${sdkVersion}"`;
+
 const serializedDefaultResource =
   '# HELP target_info Target metadata\n' +
   '# TYPE target_info gauge\n' +
-  `target_info{service_name="${serviceName}",telemetry_sdk_language="${sdkLanguage}",telemetry_sdk_name="${sdkName}",telemetry_sdk_version="${sdkVersion}"} 1\n`;
+  `target_info{${resourceAttributes}} 1\n`;
 
 class TestMetricReader extends MetricReader {
   constructor() {
@@ -104,6 +106,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(metric.dataPointType, DataPointType.SUM);
         const pointData = metric.dataPoints as DataPoint<number>[];
         assert.strictEqual(pointData.length, 1);
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         const result = serializer['_serializeSingularDataPoint'](
           metric.descriptor.name,
@@ -159,6 +165,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(metric.dataPointType, DataPointType.HISTOGRAM);
         const pointData = metric.dataPoints as DataPoint<Histogram>[];
         assert.strictEqual(pointData.length, 1);
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         const result = serializer['_serializeHistogramDataPoint'](
           metric.descriptor.name,
@@ -195,6 +205,20 @@ describe('PrometheusSerializer', () => {
             `test_bucket{foo1="bar1",foo2="bar2",le="+Inf"} 1 ${mockedHrTimeMs}\n`
         );
       });
+
+      it('serialize metric record with sum aggregator with timestamp and all resource attributes', async () => {
+        const serializer = new PrometheusSerializer(undefined, true, /.*/);
+        const result = await testSerializer(serializer);
+        assert.strictEqual(
+          result,
+          `test_count{foo1="bar1",foo2="bar2",${resourceAttributes}} 1 ${mockedHrTimeMs}\n` +
+            `test_sum{foo1="bar1",foo2="bar2",${resourceAttributes}} 5 ${mockedHrTimeMs}\n` +
+            `test_bucket{foo1="bar1",foo2="bar2",${resourceAttributes},le="1"} 0 ${mockedHrTimeMs}\n` +
+            `test_bucket{foo1="bar1",foo2="bar2",${resourceAttributes},le="10"} 1 ${mockedHrTimeMs}\n` +
+            `test_bucket{foo1="bar1",foo2="bar2",${resourceAttributes},le="100"} 1 ${mockedHrTimeMs}\n` +
+            `test_bucket{foo1="bar1",foo2="bar2",${resourceAttributes},le="+Inf"} 1 ${mockedHrTimeMs}\n`
+        );
+      });
     });
   });
 
@@ -224,6 +248,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics.length, 1);
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         const result = serializer['_serializeScopeMetrics'](scopeMetrics);
         return result;
@@ -252,6 +280,18 @@ describe('PrometheusSerializer', () => {
             `test_total{val="2"} 1 ${mockedHrTimeMs}\n`
         );
       });
+
+      it('should serialize metric record with timestamp and all resource attributes', async () => {
+        const serializer = new PrometheusSerializer(undefined, true, /.*/);
+        const result = await testSerializer(serializer);
+        assert.strictEqual(
+          result,
+          '# HELP test_total foobar\n' +
+            '# TYPE test_total counter\n' +
+            `test_total{val="1",${resourceAttributes}} 1 ${mockedHrTimeMs}\n` +
+            `test_total{val="2",${resourceAttributes}} 1 ${mockedHrTimeMs}\n`
+        );
+      });
     });
 
     describe('non-monotonic Sum', () => {
@@ -279,6 +319,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics.length, 1);
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         return serializer['_serializeScopeMetrics'](scopeMetrics);
       }
@@ -306,6 +350,19 @@ describe('PrometheusSerializer', () => {
             `test_total{val="2"} 1 ${mockedHrTimeMs}\n`
         );
       });
+
+      it('serialize metric record with timestamp and all resource attributes', async () => {
+        const serializer = new PrometheusSerializer(undefined, true, /.*/);
+
+        const result = await testSerializer(serializer);
+        assert.strictEqual(
+          result,
+          '# HELP test_total foobar\n' +
+            '# TYPE test_total gauge\n' +
+            `test_total{val="1",${resourceAttributes}} 1 ${mockedHrTimeMs}\n` +
+            `test_total{val="2",${resourceAttributes}} 1 ${mockedHrTimeMs}\n`
+        );
+      });
     });
 
     describe('Gauge', () => {
@@ -335,6 +392,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics.length, 1);
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         return serializer['_serializeScopeMetrics'](scopeMetrics);
       }
@@ -362,6 +423,18 @@ describe('PrometheusSerializer', () => {
             `test_total{val="2"} 1 ${mockedHrTimeMs}\n`
         );
       });
+
+      it('serialize metric record with timestamp and all resource attributes', async () => {
+        const serializer = new PrometheusSerializer(undefined, true, /.*/);
+        const result = await testSerializer(serializer);
+        assert.strictEqual(
+          result,
+          '# HELP test_total foobar\n' +
+            '# TYPE test_total gauge\n' +
+            `test_total{val="1",${resourceAttributes}} 1 ${mockedHrTimeMs}\n` +
+            `test_total{val="2",${resourceAttributes}} 1 ${mockedHrTimeMs}\n`
+        );
+      });
     });
 
     describe('with ExplicitBucketHistogramAggregation', () => {
@@ -395,6 +468,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics.length, 1);
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         const result = serializer['_serializeScopeMetrics'](scopeMetrics);
         return result;
@@ -422,6 +499,28 @@ describe('PrometheusSerializer', () => {
         );
       });
 
+      it('serialize cumulative metric record with all resource attributes', async () => {
+        const serializer = new PrometheusSerializer('', false, /.*/);
+        const result = await testSerializer(serializer);
+        assert.strictEqual(
+          result,
+          '# HELP test foobar\n' +
+            '# TYPE test histogram\n' +
+            `test_count{val="1",${resourceAttributes}} 3\n` +
+            `test_sum{val="1",${resourceAttributes}} 175\n` +
+            `test_bucket{val="1",${resourceAttributes},le="1"} 0\n` +
+            `test_bucket{val="1",${resourceAttributes},le="10"} 1\n` +
+            `test_bucket{val="1",${resourceAttributes},le="100"} 2\n` +
+            `test_bucket{val="1",${resourceAttributes},le="+Inf"} 3\n` +
+            `test_count{val="2",${resourceAttributes}} 1\n` +
+            `test_sum{val="2",${resourceAttributes}} 5\n` +
+            `test_bucket{val="2",${resourceAttributes},le="1"} 0\n` +
+            `test_bucket{val="2",${resourceAttributes},le="10"} 1\n` +
+            `test_bucket{val="2",${resourceAttributes},le="100"} 1\n` +
+            `test_bucket{val="2",${resourceAttributes},le="+Inf"} 1\n`
+        );
+      });
+
       it('serialize cumulative metric record on instrument that allows negative values', async () => {
         const serializer = new PrometheusSerializer();
         const reader = new TestMetricReader();
@@ -453,6 +552,10 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics.length, 1);
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
+        const resourceAttributes = resourceMetrics.resource.attributes;
+        serializer['_additionalAttributes'] = serializer[
+          '_filterResourceConstantLabels'
+        ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
         const result = serializer['_serializeScopeMetrics'](scopeMetrics);
         assert.strictEqual(
@@ -504,6 +607,10 @@ describe('PrometheusSerializer', () => {
       assert.strictEqual(metric.dataPointType, DataPointType.SUM);
       const pointData = metric.dataPoints as DataPoint<number>[];
       assert.strictEqual(pointData.length, 1);
+      const resourceAttributes = resourceMetrics.resource.attributes;
+      serializer['_additionalAttributes'] = serializer[
+        '_filterResourceConstantLabels'
+      ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
       if (exportAll) {
         const result = serializer.serialize(resourceMetrics);
@@ -595,6 +702,10 @@ describe('PrometheusSerializer', () => {
       assert.strictEqual(metric.dataPointType, DataPointType.SUM);
       const pointData = metric.dataPoints as DataPoint<number>[];
       assert.strictEqual(pointData.length, 1);
+      const resourceAttributes = resourceMetrics.resource.attributes;
+      serializer['_additionalAttributes'] = serializer[
+        '_filterResourceConstantLabels'
+      ](resourceAttributes, serializer['_withResourceConstantLabels']);
 
       const result = serializer['_serializeSingularDataPoint'](
         metric.descriptor.name,