correctly handle nil value and timestamp combinations

Signed-off-by: Lukas Wöhrl <[email protected]>

Author: woehrl01

pkg/promutil/migrate.go

@@ -112,8 +112,14 @@ func BuildMetrics(results []model.CloudwatchMetricResult, labelsSnakeCase bool,
 					if dataPoint == nil && metric.MetricMigrationParams.AddCloudwatchTimestamp {
 						// If we did not get a datapoint then the timestamp is a default value making it unusable in the
 						// exported metric. Attempting to put a fake timestamp on the metric will likely conflict with
-						// future CloudWatch timestamps which are always in the past. It's safer to skip here than guess
-						continue
+						// future CloudWatch timestamps which are always in the past. It's safer to not export any data.
+						if metric.MetricMigrationParams.ExportAllDataPoints {
+							// If we're exporting all data points, we can skip this one and check for a historical datapoint
+							continue
+						} else {
+							// If we are not exporting all data points, we better have nothing exported
+							break
+						}
 					}
 					if dataPoint == nil {
 						exportedDatapoint = math.NaN()

pkg/promutil/migrate_test.go

@@ -409,8 +409,31 @@ func TestBuildMetrics(t *testing.T) {
 						ResourceName: "arn:aws:elasticache:us-east-1:123456789012:cluster:redis-cluster",
 					},
 					{
-						//Check that if there is no data point for the latest timestamp it exports the previous one
 						MetricName: "NetworkPacketsOut",
+						MetricMigrationParams: model.MetricMigrationParams{
+							NilToZero:              true,
+							AddCloudwatchTimestamp: true,
+							ExportAllDataPoints:    true,
+						},
+						Namespace: "AWS/ElastiCache",
+						Dimensions: []model.Dimension{
+							{
+								Name:  "CacheClusterId",
+								Value: "redis-cluster",
+							},
+						},
+						GetMetricDataResult: &model.GetMetricDataResult{
+							Statistic: "Average",
+							Datapoints: []model.DatapointWithTimestamp{
+								model.NewDataPoint(nil, ts),
+								model.NewDataPoint(aws.Float64(5), ts.Add(-1*time.Minute)),
+								model.NewDataPoint(aws.Float64(6), ts.Add(-2*time.Minute)),
+							},
+						},
+						ResourceName: "arn:aws:elasticache:us-east-1:123456789012:cluster:redis-cluster",
+					},
+					{
+						MetricName: "NetworkMaxBytesIn",
 						MetricMigrationParams: model.MetricMigrationParams{
 							NilToZero:              true,
 							AddCloudwatchTimestamp: true,
@@ -530,6 +553,18 @@ func TestBuildMetrics(t *testing.T) {
 						"dimension_CacheClusterId": "redis-cluster",
 					},
 				},
+				{
+					Name:             "aws_elasticache_network_packets_out_average",
+					Value:            6,
+					Timestamp:        ts.Add(-2 * time.Minute),
+					IncludeTimestamp: true,
+					Labels: map[string]string{
+						"account_id":               "123456789012",
+						"name":                     "arn:aws:elasticache:us-east-1:123456789012:cluster:redis-cluster",
+						"region":                   "us-east-1",
+						"dimension_CacheClusterId": "redis-cluster",
+					},
+				},
 			},
 			expectedLabels: map[string]model.LabelSet{
 				"aws_elasticache_cpuutilization_average": {