Refactor Prometheus exporter

CHANGELOG.md

@@ -11,6 +11,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Added
 
 - Added an example of using metric views to customize instruments. (#3177)
+- Prometheus exporter will register with a prometheus registerer on creation, there are options to control this (#3239)
 
 ### Changed
 

exporters/prometheus/exporter_test.go

@@ -141,7 +141,18 @@ func TestPrometheusExporter(t *testing.T) {
 
 			exporter, err := New(WithGatherer(registry), WithRegisterer(registry))
 			require.NoError(t, err)
-			provider := metric.NewMeterProvider(metric.WithReader(exporter))
+
+			customBucketsView, err := view.New(
+				view.MatchInstrumentName("histogram_*"),
+				view.WithSetAggregation(aggregation.ExplicitBucketHistogram{
+					Boundaries: []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
+				}),
+			)
+			require.NoError(t, err)
+			defaultView, err := view.New(view.MatchInstrumentName("*"))
+			require.NoError(t, err)
+
+			provider := metric.NewMeterProvider(metric.WithReader(exporter, customBucketsView, defaultView))
 			meter := provider.Meter("testmeter")
 
 			tc.recordMetrics(ctx, meter)