From deb6efee8e0cc3916db39f54369ccb03f59b6cf3 Mon Sep 17 00:00:00 2001
From: Akash Suresh <akash@signalfx.com>
Date: Thu, 18 Mar 2021 20:20:51 -0400
Subject: [PATCH] exporter/signalfx: Update exclude_metrics option (#2737)

---
 exporter/signalfxexporter/README.md       |  5 ++++-
 exporter/signalfxexporter/factory.go      |  4 +---
 exporter/signalfxexporter/factory_test.go | 20 ++++++++++++++++++++
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/exporter/signalfxexporter/README.md b/exporter/signalfxexporter/README.md
index 645933fdb0117..0d91f3882c411 100644
--- a/exporter/signalfxexporter/README.md
+++ b/exporter/signalfxexporter/README.md
@@ -44,7 +44,10 @@ The following configuration options can also be configured:
 - `exclude_metrics`: List of metric filters that will determine metrics to be
   excluded from sending to Signalfx backend. If `translation_rules` options
   are enabled, the exclusion will be applied on translated metrics.
-  See [here](./testdata/config.yaml) for examples.
+  See [here](./testdata/config.yaml) for examples. Apart from the values explicitly
+  provided via this option, by default, [these](./translation/default_metrics.go) are
+  also appended to this list. Setting this option to `[]` will override all the default
+  excludes.
 - `include_metrics`: List of filters to override exclusion of any metrics.
   This option can be used to included metrics that are otherwise dropped by
   default. See [here](./translation/default_metrics.go) for a list of metrics
diff --git a/exporter/signalfxexporter/factory.go b/exporter/signalfxexporter/factory.go
index 08dfa1638dc06..8e43516cbccf6 100644
--- a/exporter/signalfxexporter/factory.go
+++ b/exporter/signalfxexporter/factory.go
@@ -187,9 +187,7 @@ func setDefaultExcludes(cfg *Config) error {
 	if err != nil {
 		return err
 	}
-	if cfg.ExcludeMetrics == nil {
-		cfg.ExcludeMetrics = defaultExcludeMetrics
-	} else {
+	if cfg.ExcludeMetrics == nil || len(cfg.ExcludeMetrics) > 0 {
 		cfg.ExcludeMetrics = append(cfg.ExcludeMetrics, defaultExcludeMetrics...)
 	}
 	return nil
diff --git a/exporter/signalfxexporter/factory_test.go b/exporter/signalfxexporter/factory_test.go
index d0e6cce9f9bb3..08219d0b5acf6 100644
--- a/exporter/signalfxexporter/factory_test.go
+++ b/exporter/signalfxexporter/factory_test.go
@@ -331,6 +331,26 @@ func TestCreateMetricsExporterWithExcludeMetrics(t *testing.T) {
 	assert.Equal(t, 11, len(config.ExcludeMetrics))
 }
 
+func TestCreateMetricsExporterWithEmptyExcludeMetrics(t *testing.T) {
+	config := &Config{
+		ExporterSettings: configmodels.ExporterSettings{
+			TypeVal: configmodels.Type(typeStr),
+			NameVal: typeStr,
+		},
+		AccessToken:    "testToken",
+		Realm:          "us1",
+		ExcludeMetrics: []dpfilters.MetricFilter{},
+	}
+
+	te, err := createMetricsExporter(context.Background(), component.ExporterCreateParams{Logger: zap.NewNop()}, config)
+	require.NoError(t, err)
+	require.NotNil(t, te)
+
+	// Validate that default excludes are overridden when exclude metrics
+	// is explicitly set to an empty slice.
+	assert.Equal(t, 0, len(config.ExcludeMetrics))
+}
+
 func testMetricsData() pdata.ResourceMetrics {
 	md := internaldata.MetricsData{
 		Metrics: []*metricspb.Metric{