From 792dad3a760c83a6de8f21810340bb276399105e Mon Sep 17 00:00:00 2001
From: Martin Magakian <martin@keymantics.com>
Date: Mon, 13 Jan 2020 21:37:15 +0100
Subject: [PATCH] Discard Summary metrics

---
 cmd/prom-aggregation-gateway/main.go      | 18 ++++++++++--------
 cmd/prom-aggregation-gateway/main_test.go | 15 +++++++++++++++
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/cmd/prom-aggregation-gateway/main.go b/cmd/prom-aggregation-gateway/main.go
index c27bec1..91fc65d 100644
--- a/cmd/prom-aggregation-gateway/main.go
+++ b/cmd/prom-aggregation-gateway/main.go
@@ -117,12 +117,10 @@ func mergeMetric(ty dto.MetricType, a, b *dto.Metric) *dto.Metric {
 			},
 		}
 
-	case dto.MetricType_SUMMARY:
-		// No way of merging summaries, abort.
+	default:
+		// No way of merging other metrics types, discard.
 		return nil
 	}
-
-	return nil
 }
 
 func mergeFamily(a, b *dto.MetricFamily) (*dto.MetricFamily, error) {
@@ -206,15 +204,19 @@ func (a *aggate) parseAndMerge(r io.Reader) error {
 	a.familiesLock.Lock()
 	defer a.familiesLock.Unlock()
 	for name, family := range inFamilies {
-		// Sort labels in case source sends them inconsistently
-		for _, m := range family.Metric {
-			sort.Sort(byName(m.Label))
+		// Discard unsupported types
+		if *family.Type == dto.MetricType_SUMMARY {
+			continue
 		}
-
 		if err := validateFamily(family); err != nil {
 			return err
 		}
 
+		// Sort labels in case source sends them inconsistently
+		for _, m := range family.Metric {
+			sort.Sort(byName(m.Label))
+		}
+
 		// family must be sorted for the merge
 		sort.Sort(byLabel(family.Metric))
 
diff --git a/cmd/prom-aggregation-gateway/main_test.go b/cmd/prom-aggregation-gateway/main_test.go
index a205178..b034757 100644
--- a/cmd/prom-aggregation-gateway/main_test.go
+++ b/cmd/prom-aggregation-gateway/main_test.go
@@ -137,6 +137,20 @@ counter{b="b",a="a"} 2
 	reorderedLabelsResult = `# HELP counter A counter
 # TYPE counter counter
 counter{a="a",b="b"} 3
+`
+
+	summaryInput = `# HELP cpu_temperature_celsius Current temperature of the CPU.
+# TYPE cpu_temperature_celsius summary
+cpu_temperature_celsius_sum 30.2
+cpu_temperature_celsius_count 1
+# HELP counter A counter
+# TYPE counter counter
+counter 1
+`
+
+	summaryDiscardedOutput = `# HELP counter A counter
+# TYPE counter counter
+counter 2
 `
 )
 
@@ -153,6 +167,7 @@ func TestAggate(t *testing.T) {
 		{labelFields1, labelFields2, labelFieldResult, nil, nil},
 		{duplicateLabels, "", "", fmt.Errorf("%s", duplicateError), nil},
 		{reorderedLabels1, reorderedLabels2, reorderedLabelsResult, nil, nil},
+		{summaryInput, summaryInput, summaryDiscardedOutput, nil, nil},
 	} {
 		a := newAggate()