Merge pull request #1114 from circleci/dm/timestamp-httpmetrics

Add timestamp to httpmetric

o11y/httpmetrics/provider.go

@@ -39,10 +39,11 @@ type Provider struct {
 }
 
 type metricData struct {
-	Type  string   `json:"type"`
-	Name  string   `json:"name"`
-	Value float64  `json:"value"`
-	Tags  []string `json:"tags"`
+	Type      string   `json:"type"`
+	Name      string   `json:"name"`
+	Timestamp int64    `json:"timestamp"`
+	Value     float64  `json:"value"`
+	Tags      []string `json:"tags"`
 }
 
 type Tags map[string]string
@@ -124,10 +125,11 @@ func (m *Provider) record(metricType, metricName string, metricValue float64, me
 		name = fmt.Sprintf("%s.%s", m.namespace, name)
 	}
 	m.data = append(m.data, metricData{
-		Type:  metricType,
-		Name:  name,
-		Value: metricValue,
-		Tags:  metricTags,
+		Type:      metricType,
+		Name:      name,
+		Timestamp: time.Now().Unix(),
+		Value:     metricValue,
+		Tags:      metricTags,
 	})
 }
 

o11y/httpmetrics/provider_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 	"time"
 
+	gcmp "github.com/google/go-cmp/cmp"
 	"golang.org/x/sync/errgroup"
 	"gotest.tools/v3/assert"
 	"gotest.tools/v3/assert/cmp"
@@ -132,7 +133,11 @@ func TestProvider_Record(t *testing.T) {
 				m.record(aMet.Type, aMet.Name, aMet.Value, aMet.Tags)
 			}
 
-			assert.Check(t, cmp.DeepEqual(m.data, tt.expectedMetricsData))
+			for i := range tt.expectedMetricsData {
+				tt.expectedMetricsData[i].Timestamp = time.Now().Unix()
+			}
+
+			assert.Check(t, cmp.DeepEqual(m.data, tt.expectedMetricsData, equateApproxUnixTime(1)))
 		})
 	}
 }
@@ -255,7 +260,11 @@ func TestProvider_Publish(t *testing.T) {
 			err := eg.Wait()
 			assert.NilError(t, err)
 
-			assert.Check(t, cmp.DeepEqual(m.data, tt.expectedMetricsData))
+			for i := range tt.expectedMetricsData {
+				tt.expectedMetricsData[i].Timestamp = time.Now().Unix()
+			}
+
+			assert.Check(t, cmp.DeepEqual(m.data, tt.expectedMetricsData, equateApproxUnixTime(1)))
 		})
 	}
 }
@@ -353,3 +362,28 @@ func TestProvider_New(t *testing.T) {
 		})
 	}
 }
+
+func equateApproxUnixTime(marginSec int64) gcmp.Option {
+	if marginSec < 0 {
+		panic("margin must be a non-negative number")
+	}
+	a := timeApproximator{marginSec}
+	return gcmp.FilterValues(areNonZeroTimes, gcmp.Comparer(a.compare))
+}
+
+func areNonZeroTimes(x, y int64) bool {
+	return x > 0 && y > 0
+}
+
+type timeApproximator struct {
+	marginSec int64
+}
+
+func (a timeApproximator) compare(x, y int64) bool {
+	if x > y {
+		// Ensure x is always before y
+		x, y = y, x
+	}
+	// We're within the margin if x+margin >= y.
+	return x+a.marginSec >= y
+}