fix(prometheus-exporter): remove generation of job and instance labels

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

@@ -171,43 +171,6 @@ function stringify(
   }\n`;
 }
 
-function filterReservedResourceAttributes(resource: Resource): MetricAttributes {
-  return Object.fromEntries(
-    Object.entries(resource.attributes)
-      .filter(([key]) => {
-        if (key === 'job') {
-          diag.warn('Cannot serialize reserved resource attribute "job".');
-          return true;
-        }
-        if (key === 'instance') {
-          diag.warn('Cannot serialize reserved resource attribute "instance".');
-          return true;
-        }
-
-        // drop any entries that will be used to construct 'job' and 'instance'
-        return key !== 'service.name' && key !== 'service.namespace' && key !== 'service.instance.id';
-      }
-      ));
-}
-
-function extractJobLabel(resource: Resource): string | undefined {
-  const serviceName = resource.attributes['service.name'];
-  const serviceNamespace = resource.attributes['service.namespace'];
-
-  if (serviceNamespace != null && serviceName != null) {
-    return `${serviceNamespace.toString()}/${serviceName.toString()}`;
-  } else if (serviceName != null) {
-    return serviceName.toString();
-  }
-
-  return undefined;
-}
-
-function extractInstanceLabel(resource: Resource): string | undefined {
-  const instance = resource.attributes['service.instance.id'];
-  return instance?.toString();
-}
-
 export class PrometheusSerializer {
   private _prefix: string | undefined;
   private _appendTimestamp: boolean;
@@ -358,14 +321,7 @@ export class PrometheusSerializer {
     const help = `# HELP ${name} Target metadata`;
     const type = `# TYPE ${name} gauge`;
 
-    const resourceAttributes = filterReservedResourceAttributes(resource);
-
-    const otherAttributes = {
-      job: extractJobLabel(resource),
-      instance: extractInstanceLabel(resource)
-    };
-
-    const results = stringify(name, resourceAttributes, 1, undefined, otherAttributes).trim();
+    const results = stringify(name, resource.attributes, 1).trim();
     return `${help}\n${type}\n${results}\n`;
   }
 }

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

@@ -33,7 +33,7 @@ import { Counter } from '@opentelemetry/api-metrics';
 const serializedEmptyResourceLines = [
   '# HELP target_info Target metadata',
   '# TYPE target_info gauge',
-  'target_info{job="",instance=""} 1'
+  'target_info 1'
 ];
 
 describe('PrometheusExporter', () => {

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

@@ -48,7 +48,7 @@ const attributes = {
 const serializedEmptyResource =
   '# HELP target_info Target metadata\n' +
   '# TYPE target_info gauge\n' +
-  'target_info{job="",instance=""} 1\n';
+  'target_info 1\n';
 
 class TestMetricReader extends MetricReader {
   constructor() {
@@ -651,111 +651,7 @@ describe('PrometheusSerializer', () => {
         result,
         '# HELP target_info Target metadata\n' +
         '# TYPE target_info gauge\n' +
-        'target_info{env="prod",hostname="myhost",datacenter="sdc",region="europe",owner="frontend",job="",instance=""} 1\n'
-      );
-    });
-
-    it('should drop service attributes', () => {
-      const serializer = new PrometheusSerializer(undefined, true);
-      const result = serializer['_serializeResource'](new Resource({
-        env: 'prod',
-        hostname: 'myhost',
-        datacenter: 'sdc',
-        region: 'europe',
-        owner: 'frontend',
-        'service.name': 'name',
-        'service.namespace': 'namespace',
-        'service.instance.id': 'instance id'
-      }));
-
-      assert.strictEqual(
-        result,
-        '# HELP target_info Target metadata\n' +
-        '# TYPE target_info gauge\n' +
-        'target_info{env="prod",hostname="myhost",datacenter="sdc",region="europe",owner="frontend",job="namespace/name",instance="instance id"} 1\n'
-      );
-    });
-
-    it('with undefined service.instance.id should add empty instance id', () => {
-      const serializer = new PrometheusSerializer(undefined, true);
-      const result = serializer['_serializeResource'](new Resource({
-        foo: 'bar',
-        'service.name': 'name',
-        'service.namespace': 'namespace',
-      }));
-
-      assert.strictEqual(
-        result,
-        '# HELP target_info Target metadata\n' +
-        '# TYPE target_info gauge\n' +
-        'target_info{foo="bar",job="namespace/name",instance=""} 1\n'
-      );
-    });
-
-    it('with undefined service.instance.id should add empty instance id', () => {
-      const serializer = new PrometheusSerializer(undefined, true);
-      const result = serializer['_serializeResource'](new Resource({
-        foo: 'bar',
-        'service.name': 'name',
-        'service.namespace': 'namespace',
-      }));
-
-      assert.strictEqual(
-        result,
-        '# HELP target_info Target metadata\n' +
-        '# TYPE target_info gauge\n' +
-        'target_info{foo="bar",job="namespace/name",instance=""} 1\n'
-      );
-    });
-
-    it('with undefined service.namespace should only use service.name for "job"', () => {
-      const serializer = new PrometheusSerializer(undefined, true);
-      const result = serializer['_serializeResource'](new Resource({
-        foo: 'bar',
-        'service.name': 'name',
-        'service.instance.id': '123'
-      }));
-
-      assert.strictEqual(
-        result,
-        '# HELP target_info Target metadata\n' +
-        '# TYPE target_info gauge\n' +
-        'target_info{foo="bar",job="name",instance="123"} 1\n'
-      );
-    });
-
-    it('with undefined service.namespace and service.name should add empty "job"', () => {
-      // service.name MUST exist. But PrometheusSerializer is exported and used by non-SDK packages.
-      // In case semantic conventions are not adhered to, add empty as a fallback.
-      const serializer = new PrometheusSerializer(undefined, true);
-      const result = serializer['_serializeResource'](new Resource({
-        foo: 'bar',
-        'service.instance.id': '123'
-      }));
-
-      assert.strictEqual(
-        result,
-        '# HELP target_info Target metadata\n' +
-        '# TYPE target_info gauge\n' +
-        'target_info{foo="bar",job="",instance="123"} 1\n'
-      );
-    });
-
-    it('with defined service.namespace and undefined service.name should add empty "job"', () => {
-      // service.name MUST exist. But PrometheusSerializer is exported and used by non-SDK packages.
-      // In case semantic conventions are not adhered to, add empty as a fallback.
-      const serializer = new PrometheusSerializer(undefined, true);
-      const result = serializer['_serializeResource'](new Resource({
-        foo: 'bar',
-        'service.instance.id': '123',
-        'service.namespace': 'namespace'
-      }));
-
-      assert.strictEqual(
-        result,
-        '# HELP target_info Target metadata\n' +
-        '# TYPE target_info gauge\n' +
-        'target_info{foo="bar",job="",instance="123"} 1\n'
+        'target_info{env="prod",hostname="myhost",datacenter="sdc",region="europe",owner="frontend"} 1\n'
       );
     });
   });