feat: update prometheus api to support range.step (#1801)

Signed-off-by: Rakshit Gondwal <[email protected]> Signed-off-by: Florian Bacher <[email protected]> Co-authored-by: Florian Bacher <[email protected]>
keptn · Aug 10, 2023 · e64fcd6 · e64fcd6
1 parent 193f520
commit e64fcd6
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Showing 2 changed files with 236 additions and 32 deletions.
diff --git a/metrics-operator/controllers/common/providers/prometheus/prometheus.go b/metrics-operator/controllers/common/providers/prometheus/prometheus.go
@@ -2,6 +2,7 @@ package prometheus
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"      //nolint:gci
 	"net/http" //nolint:gci
 	"time"
@@ -13,6 +14,10 @@ import (
 	"github.com/prometheus/common/model"
 )
 
+var errCouldNotCast = fmt.Errorf("could not cast result")
+var errNoValues = fmt.Errorf("no values in query result")
+var errTooManyValues = fmt.Errorf("too many values in query result")
+
 type KeptnPrometheusProvider struct {
 	Log        logr.Logger
 	HttpClient http.Client
@@ -37,7 +42,7 @@ func (r *KeptnPrometheusProvider) EvaluateQuery(ctx context.Context, metric metr
 		if len(warnings) != 0 {
 			r.Log.Info("Prometheus API returned warnings: " + warnings[0])
 		}
-		return getResultForMatrix(result, r)
+		return getResultForMatrix(result)
 	} else {
 		result, warnings, err := evaluateQueryWithoutRange(ctx, metric, r, api)
 		if err != nil {
@@ -46,29 +51,60 @@ func (r *KeptnPrometheusProvider) EvaluateQuery(ctx context.Context, metric metr
 		if len(warnings) != 0 {
 			r.Log.Info("Prometheus API returned warnings: " + warnings[0])
 		}
-		return getResultForVector(result, r)
+		return getResultForVector(result)
 	}
 }
 
+// EvaluateQueryForStep fetches the metric values from prometheus provider
+func (r *KeptnPrometheusProvider) EvaluateQueryForStep(ctx context.Context, metric metricsapi.KeptnMetric, provider metricsapi.KeptnMetricsProvider) ([]string, []byte, error) {
+	ctx, cancel := context.WithTimeout(ctx, 20*time.Second)
+	defer cancel()
+
+	client, err := promapi.NewClient(promapi.Config{Address: provider.Spec.TargetServer, Client: &r.HttpClient})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	api := prometheus.NewAPI(client)
+	result, warnings, err := evaluateQueryWithRange(ctx, metric, r, api)
+	if err != nil {
+		return nil, nil, err
+	}
+	if len(warnings) != 0 {
+		r.Log.Info("Prometheus API returned warnings: " + warnings[0])
+	}
+	return getResultForStepMatrix(result)
+}
+
 func evaluateQueryWithRange(ctx context.Context, metric metricsapi.KeptnMetric, r *KeptnPrometheusProvider, api prometheus.API) (model.Value, prometheus.Warnings, error) {
 	queryTime := time.Now().UTC()
 	// Get the duration
 	queryInterval, err := time.ParseDuration(metric.Spec.Range.Interval)
 	if err != nil {
 		return nil, nil, err
 	}
+	var stepInterval time.Duration
+	if metric.Spec.Range.Step != "" {
+		stepTime := metric.Spec.Range.Step
+		stepInterval, err = time.ParseDuration(stepTime)
+		if err != nil {
+			return nil, nil, err
+		}
+	} else {
+		stepInterval = queryInterval
+	}
 	// Convert type Duration to type Time
 	startTime := queryTime.Add(-queryInterval).UTC()
 	r.Log.Info(fmt.Sprintf(
 		"Running query: /api/v1/query_range?query=%s&start=%d&end=%d&step=%v",
 		metric.Spec.Query,
 		startTime.Unix(), queryTime.Unix(),
-		queryInterval,
+		stepInterval,
 	))
 	queryRange := prometheus.Range{
 		Start: startTime,
 		End:   queryTime,
-		Step:  queryInterval,
+		Step:  stepInterval,
 	}
 	result, warnings, err := api.QueryRange(
 		ctx,
@@ -101,23 +137,21 @@ func evaluateQueryWithoutRange(ctx context.Context, metric metricsapi.KeptnMetri
 	return result, warnings, nil
 }
 
-func getResultForMatrix(result model.Value, r *KeptnPrometheusProvider) (string, []byte, error) {
+func getResultForMatrix(result model.Value) (string, []byte, error) {
 	// check if we can cast the result to a matrix
 	resultMatrix, ok := result.(model.Matrix)
 	if !ok {
-		return "", nil, fmt.Errorf("could not cast result")
+		return "", nil, errCouldNotCast
 	}
 	// We are only allowed to return one value, if not the query may be malformed
 	// we are using two different errors to give the user more information about the result
 	// There can be more than 1 values in the matrixResults but we are defining the step
 	// parameter as the interval itself, hence there can only be one value.
 	// This logic should be changed, once we work onto the aggregation functions.
 	if len(resultMatrix) == 0 {
-		r.Log.Info("No values in query result")
-		return "", nil, fmt.Errorf("no values in query result")
+		return "", nil, errNoValues
 	} else if len(resultMatrix) > 1 {
-		r.Log.Info("Too many values in the query result")
-		return "", nil, fmt.Errorf("too many values in the query result")
+		return "", nil, errTooManyValues
 	}
 	value := resultMatrix[0].Values[0].Value.String()
 	b, err := resultMatrix[0].Values[0].Value.MarshalJSON()
@@ -127,20 +161,18 @@ func getResultForMatrix(result model.Value, r *KeptnPrometheusProvider) (string,
 	return value, b, nil
 }
 
-func getResultForVector(result model.Value, r *KeptnPrometheusProvider) (string, []byte, error) {
+func getResultForVector(result model.Value) (string, []byte, error) {
 	// check if we can cast the result to a vector
 	resultVector, ok := result.(model.Vector)
 	if !ok {
-		return "", nil, fmt.Errorf("could not cast result")
+		return "", nil, errCouldNotCast
 	}
 	// We are only allowed to return one value, if not the query may be malformed
 	// we are using two different errors to give the user more information about the result
 	if len(resultVector) == 0 {
-		r.Log.Info("No values in query result")
-		return "", nil, fmt.Errorf("no values in query result")
+		return "", nil, errNoValues
 	} else if len(resultVector) > 1 {
-		r.Log.Info("Too many values in the query result")
-		return "", nil, fmt.Errorf("too many values in the query result")
+		return "", nil, errTooManyValues
 	}
 	value := resultVector[0].Value.String()
 	b, err := resultVector[0].Value.MarshalJSON()
@@ -149,3 +181,29 @@ func getResultForVector(result model.Value, r *KeptnPrometheusProvider) (string,
 	}
 	return value, b, nil
 }
+
+func getResultForStepMatrix(result model.Value) ([]string, []byte, error) {
+	// check if we can cast the result to a matrix
+	resultMatrix, ok := result.(model.Matrix)
+	if !ok {
+		return nil, nil, errCouldNotCast
+	}
+
+	if len(resultMatrix) == 0 {
+		return nil, nil, errNoValues
+	} else if len(resultMatrix) > 1 {
+		return nil, nil, errTooManyValues
+	}
+
+	resultSlice := make([]string, len(resultMatrix[0].Values))
+	for i, value := range resultMatrix[0].Values {
+		resultSlice[i] = value.Value.String()
+	}
+
+	b, err := json.Marshal(resultSlice)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return resultSlice, b, nil
+}