Merge pull request #356 from prometheus/refactor/retrieval-ingester

Make retrieval work with client's new Ingester interface.

retrieval/target.go

@@ -202,6 +202,19 @@ func (t *target) Scrape(earliest time.Time, results chan<- *extraction.Result) e
 
 const acceptHeader = `application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.7,application/json;schema=prometheus/telemetry;version=0.0.2;q=0.2,*/*;q=0.1`
 
+type extendLabelsIngester struct {
+	baseLabels clientmodel.LabelSet
+	results chan<- *extraction.Result
+}
+
+func (i *extendLabelsIngester) Ingest(r *extraction.Result) error {
+	for _, s := range r.Samples {
+		s.Metric.MergeFromLabelSet(i.baseLabels, clientmodel.ExporterLabelPrefix)
+	}
+	i.results <- r
+	return nil
+}
+
 func (t *target) scrape(timestamp time.Time, results chan<- *extraction.Result) (err error) {
 	defer func(start time.Time) {
 		ms := float64(time.Since(start)) / float64(time.Millisecond)
@@ -238,20 +251,22 @@ func (t *target) scrape(timestamp time.Time, results chan<- *extraction.Result)
 		baseLabels[baseLabel] = baseValue
 	}
 
-	processOptions := &extraction.ProcessOptions{
-		Timestamp:  timestamp,
-		BaseLabels: baseLabels,
-	}
-
 	// N.B. - It is explicitly required to extract the entire payload before
-	//        attempting to deserialize, as the underlying reader expects will
+	//        attempting to deserialize, as the underlying reader will interpret
-	//        interpret pending data as a truncated message.
+	//        pending data as a truncated message.
 	buf := new(bytes.Buffer)
 	if _, err := buf.ReadFrom(resp.Body); err != nil {
 		return err
 	}
 
-	return processor.ProcessSingle(buf, results, processOptions)
+	ingester := &extendLabelsIngester{
+		baseLabels: baseLabels,
+		results: results,
+	}
+	processOptions := &extraction.ProcessOptions{
+		Timestamp:  timestamp,
+	}
+	return processor.ProcessSingle(buf, ingester, processOptions)
 }
 
 func (t *target) State() TargetState {