Update expfmt.NewDecoder usage

retrieval/target.go

@@ -443,10 +443,7 @@ func (t *Target) scrape(appender storage.SampleAppender) (err error) {
 		return fmt.Errorf("server returned HTTP status %s", resp.Status)
 	}
 
-	dec, err := expfmt.NewDecoder(resp.Body, resp.Header)
-	if err != nil {
-		return err
-	}
+	dec := expfmt.NewDecoder(resp.Body, expfmt.ResponseFormat(resp.Header))
 
 	sdec := expfmt.SampleDecoder{
 		Dec: dec,

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -36,39 +36,67 @@ type DecodeOptions struct {
 	Timestamp model.Time
 }
 
-// NewDecoder returns a new decoder based on the HTTP header.
-func NewDecoder(r io.Reader, h http.Header) (Decoder, error) {
+// ResponseFormat extracts the correct format from a HTTP response header.
+// If no matching format can be found FormatUnknown is returned.
+func ResponseFormat(h http.Header) Format {
 	ct := h.Get(hdrContentType)
 
 	mediatype, params, err := mime.ParseMediaType(ct)
 	if err != nil {
-		return nil, fmt.Errorf("invalid Content-Type header %q: %s", ct, err)
+		return FmtUnknown
 	}
 
 	const (
-		protoType = ProtoType + "/" + ProtoSubType
 		textType = "text/plain"
+		jsonType = "application/json"
 	)
 
 	switch mediatype {
-	case protoType:
-		if p := params["proto"]; p != ProtoProtocol {
-			return nil, fmt.Errorf("unrecognized protocol message %s", p)
+	case ProtoType:
+		if p, ok := params["proto"]; ok && p != ProtoProtocol {
+			return FmtUnknown
 		}
-		if e := params["encoding"]; e != "delimited" {
-			return nil, fmt.Errorf("unsupported encoding %s", e)
+		if e, ok := params["encoding"]; ok && e != "delimited" {
+			return FmtUnknown
 		}
-		return &protoDecoder{r: r}, nil
+		return FmtProtoDelim
 
 	case textType:
-		if v, ok := params["version"]; ok && v != "0.0.4" {
-			return nil, fmt.Errorf("unrecognized protocol version %s", v)
+		if v, ok := params["version"]; ok && v != TextVersion {
+			return FmtUnknown
 		}
-		return &textDecoder{r: r}, nil
+		return FmtText
 
-	default:
-		return nil, fmt.Errorf("unsupported media type %q, expected %q or %q", mediatype, protoType, textType)
+	case jsonType:
+		var prometheusAPIVersion string
+
+		if params["schema"] == "prometheus/telemetry" && params["version"] != "" {
+			prometheusAPIVersion = params["version"]
+		} else {
+			prometheusAPIVersion = h.Get("X-Prometheus-API-Version")
 		}
+
+		switch prometheusAPIVersion {
+		case "0.0.2", "":
+			return fmtJSON2
+		default:
+			return FmtUnknown
+		}
+	}
+
+	return FmtUnknown
+}
+
+// NewDecoder returns a new decoder based on the given input format.
+// If the input format does not imply otherwise, a text format decoder is returned.
+func NewDecoder(r io.Reader, format Format) Decoder {
+	switch format {
+	case FmtProtoDelim:
+		return &protoDecoder{r: r}
+	case fmtJSON2:
+		return newJSON2Decoder(r)
+	}
+	return &textDecoder{r: r}
 }
 
 // protoDecoder implements the Decoder interface for protocol buffers.
@@ -101,12 +129,15 @@ func (d *textDecoder) Decode(v *dto.MetricFamily) error {
 		if len(fams) == 0 {
 			return io.EOF
 		}
+		d.fams = make([]*dto.MetricFamily, 0, len(fams))
 		for _, f := range fams {
 			d.fams = append(d.fams, f)
 		}
 	}
-	*v = *d.fams[len(d.fams)-1]
-	d.fams = d.fams[:len(d.fams)-1]
+
+	*v = *d.fams[0]
+	d.fams = d.fams[1:]
+
 	return nil
 }
 
@@ -272,7 +303,6 @@ func extractSummary(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 			})
 		}
 
-		if m.Summary.SampleSum != nil {
 		lset := make(model.LabelSet, len(m.Label)+1)
 		for _, p := range m.Label {
 			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
@@ -284,10 +314,8 @@ func extractSummary(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 			Value:     model.SampleValue(m.Summary.GetSampleSum()),
 			Timestamp: timestamp,
 		})
-		}
 
-		if m.Summary.SampleCount != nil {
-			lset := make(model.LabelSet, len(m.Label)+1)
+		lset = make(model.LabelSet, len(m.Label)+1)
 		for _, p := range m.Label {
 			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
 		}
@@ -299,7 +327,6 @@ func extractSummary(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 			Timestamp: timestamp,
 		})
 	}
-	}
 
 	return samples
 }
@@ -338,7 +365,6 @@ func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 			})
 		}
 
-		if m.Histogram.SampleSum != nil {
 		lset := make(model.LabelSet, len(m.Label)+1)
 		for _, p := range m.Label {
 			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
@@ -350,10 +376,8 @@ func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 			Value:     model.SampleValue(m.Histogram.GetSampleSum()),
 			Timestamp: timestamp,
 		})
-		}
 
-		if m.Histogram.SampleCount != nil {
-			lset := make(model.LabelSet, len(m.Label)+1)
+		lset = make(model.LabelSet, len(m.Label)+1)
 		for _, p := range m.Label {
 			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
 		}
@@ -367,7 +391,7 @@ func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 		samples = append(samples, count)
 
 		if !infSeen {
-				// Append a infinity bucket sample.
+			// Append an infinity bucket sample.
 			lset := make(model.LabelSet, len(m.Label)+2)
 			for _, p := range m.Label {
 				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
@@ -382,7 +406,6 @@ func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 			})
 		}
 	}
-	}
 
 	return samples
 }

vendor/github.com/prometheus/common/expfmt/encode.go

@@ -41,7 +41,7 @@ func (e encoder) Encode(v *dto.MetricFamily) error {
 func Negotiate(h http.Header) Format {
 	for _, ac := range goautoneg.ParseAccept(h.Get(hdrAccept)) {
 		// Check for protocol buffer
-		if ac.Type == ProtoType && ac.SubType == ProtoSubType && ac.Params["proto"] == ProtoProtocol {
+		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
 				return FmtProtoDelim

vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -19,16 +19,19 @@ type Format string
 const (
 	TextVersion = "0.0.4"
 
-	ProtoType     = `application`
-	ProtoSubType  = `vnd.google.protobuf`
+	ProtoType     = `application/vnd.google.protobuf`
 	ProtoProtocol = `io.prometheus.client.MetricFamily`
-	ProtoFmt      = ProtoType + "/" + ProtoSubType + "; proto=" + ProtoProtocol + ";"
+	ProtoFmt      = ProtoType + "; proto=" + ProtoProtocol + ";"
 
 	// The Content-Type values for the different wire protocols.
+	FmtUnknown      Format = `<unknown>`
 	FmtText         Format = `text/plain; version=` + TextVersion
 	FmtProtoDelim   Format = ProtoFmt + ` encoding=delimited`
 	FmtProtoText    Format = ProtoFmt + ` encoding=text`
 	FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text`
+
+	// fmtJSON2 is hidden as it is deprecated.
+	fmtJSON2 Format = `application/json; version=0.0.2`
 )
 
 const (

vendor/github.com/prometheus/common/expfmt/json_decode.go

@@ -0,0 +1,162 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"sort"
+
+	"github.com/golang/protobuf/proto"
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/common/model"
+)
+
+type json2Decoder struct {
+	dec  *json.Decoder
+	fams []*dto.MetricFamily
+}
+
+func newJSON2Decoder(r io.Reader) Decoder {
+	return &json2Decoder{
+		dec: json.NewDecoder(r),
+	}
+}
+
+type histogram002 struct {
+	Labels model.LabelSet     `json:"labels"`
+	Values map[string]float64 `json:"value"`
+}
+
+type counter002 struct {
+	Labels model.LabelSet `json:"labels"`
+	Value  float64        `json:"value"`
+}
+
+func protoLabelSet(base, ext model.LabelSet) []*dto.LabelPair {
+	labels := base.Clone().Merge(ext)
+	delete(labels, model.MetricNameLabel)
+
+	names := make([]string, 0, len(labels))
+	for ln := range labels {
+		names = append(names, string(ln))
+	}
+	sort.Strings(names)
+
+	pairs := make([]*dto.LabelPair, 0, len(labels))
+
+	for _, ln := range names {
+		lv := labels[model.LabelName(ln)]
+
+		pairs = append(pairs, &dto.LabelPair{
+			Name:  proto.String(ln),
+			Value: proto.String(string(lv)),
+		})
+	}
+
+	return pairs
+}
+
+func (d *json2Decoder) more() error {
+	var entities []struct {
+		BaseLabels model.LabelSet `json:"baseLabels"`
+		Docstring  string         `json:"docstring"`
+		Metric     struct {
+			Type   string          `json:"type"`
+			Values json.RawMessage `json:"value"`
+		} `json:"metric"`
+	}
+
+	if err := d.dec.Decode(&entities); err != nil {
+		return err
+	}
+	for _, e := range entities {
+		f := &dto.MetricFamily{
+			Name:   proto.String(string(e.BaseLabels[model.MetricNameLabel])),
+			Help:   proto.String(e.Docstring),
+			Type:   dto.MetricType_UNTYPED.Enum(),
+			Metric: []*dto.Metric{},
+		}
+
+		d.fams = append(d.fams, f)
+
+		switch e.Metric.Type {
+		case "counter", "gauge":
+			var values []counter002
+
+			if err := json.Unmarshal(e.Metric.Values, &values); err != nil {
+				return fmt.Errorf("could not extract %s value: %s", e.Metric.Type, err)
+			}
+
+			for _, ctr := range values {
+				f.Metric = append(f.Metric, &dto.Metric{
+					Label: protoLabelSet(e.BaseLabels, ctr.Labels),
+					Untyped: &dto.Untyped{
+						Value: proto.Float64(ctr.Value),
+					},
+				})
+			}
+
+		case "histogram":
+			var values []histogram002
+
+			if err := json.Unmarshal(e.Metric.Values, &values); err != nil {
+				return fmt.Errorf("could not extract %s value: %s", e.Metric.Type, err)
+			}
+
+			for _, hist := range values {
+				quants := make([]string, 0, len(values))
+				for q := range hist.Values {
+					quants = append(quants, q)
+				}
+
+				sort.Strings(quants)
+
+				for _, q := range quants {
+					value := hist.Values[q]
+					// The correct label is "quantile" but to not break old expressions
+					// this remains "percentile"
+					hist.Labels["percentile"] = model.LabelValue(q)
+
+					f.Metric = append(f.Metric, &dto.Metric{
+						Label: protoLabelSet(e.BaseLabels, hist.Labels),
+						Untyped: &dto.Untyped{
+							Value: proto.Float64(value),
+						},
+					})
+				}
+			}
+
+		default:
+			return fmt.Errorf("unknown metric type %q", e.Metric.Type)
+		}
+	}
+	return nil
+}
+
+// Decode implements the Decoder interface.
+func (d *json2Decoder) Decode(v *dto.MetricFamily) error {
+	if len(d.fams) == 0 {
+		if err := d.more(); err != nil {
+			return err
+		}
+	}
+
+	*v = *d.fams[0]
+	d.fams = d.fams[1:]
+
+	return nil
+}

vendor/github.com/prometheus/common/expfmt/text_create.go

@@ -41,9 +41,6 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 	if name == "" {
 		return written, fmt.Errorf("MetricFamily has no name: %s", in)
 	}
-	if in.Type == nil {
-		return written, fmt.Errorf("MetricFamily has no type: %s", in)
-	}
 
 	// Comments, first HELP, then TYPE.
 	if in.Help != nil {

vendor/vendor.json

@@ -74,8 +74,8 @@
 		},
 		{
 			"path": "github.com/prometheus/common/expfmt",
-			"revision": "e5bcf05f3c1b99df9892e773349e88d038f0e93c",
-			"revisionTime": "2015-09-17T12:22:22+02:00"
+			"revision": "51d43993bd4018e9470540600641285cad786840",
+			"revisionTime": "2015-09-22T12:03:38+02:00"
 		},
 		{
 			"path": "github.com/prometheus/common/model",