Update vendored packages

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

@@ -31,6 +31,7 @@ type Decoder interface {
 	Decode(*dto.MetricFamily) error
 }
 
+// DecodeOptions contains options used by the Decoder and in sample extraction.
 type DecodeOptions struct {
 	// Timestamp is added to each value from the stream that has no explicit timestamp set.
 	Timestamp model.Time
@@ -142,6 +143,8 @@ func (d *textDecoder) Decode(v *dto.MetricFamily) error {
 	return nil
 }
 
+// SampleDecoder wraps a Decoder to extract samples from the metric families
+// decoded by the wrapped Decoder.
 type SampleDecoder struct {
 	Dec  Decoder
 	Opts *DecodeOptions
@@ -149,37 +152,51 @@ type SampleDecoder struct {
 	f dto.MetricFamily
 }
 
+// Decode calls the Decode method of the wrapped Decoder and then extracts the
+// samples from the decoded MetricFamily into the provided model.Vector.
 func (sd *SampleDecoder) Decode(s *model.Vector) error {
-	if err := sd.Dec.Decode(&sd.f); err != nil {
+	err := sd.Dec.Decode(&sd.f)
+	if err != nil {
 		return err
 	}
-	*s = extractSamples(&sd.f, sd.Opts)
-	return nil
+	*s, err = extractSamples(&sd.f, sd.Opts)
+	return err
 }
 
-// Extract samples builds a slice of samples from the provided metric families.
-func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) model.Vector {
-	var all model.Vector
+// ExtractSamples builds a slice of samples from the provided metric
+// families. If an error occurs during sample extraction, it continues to
+// extract from the remaining metric families. The returned error is the last
+// error that has occured.
+func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) (model.Vector, error) {
+	var (
+		all     model.Vector
+		lastErr error
+	)
 	for _, f := range fams {
-		all = append(all, extractSamples(f, o)...)
+		some, err := extractSamples(f, o)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		all = append(all, some...)
 	}
-	return all
+	return all, lastErr
 }
 
-func extractSamples(f *dto.MetricFamily, o *DecodeOptions) model.Vector {
+func extractSamples(f *dto.MetricFamily, o *DecodeOptions) (model.Vector, error) {
 	switch f.GetType() {
 	case dto.MetricType_COUNTER:
-		return extractCounter(o, f)
+		return extractCounter(o, f), nil
 	case dto.MetricType_GAUGE:
-		return extractGauge(o, f)
+		return extractGauge(o, f), nil
 	case dto.MetricType_SUMMARY:
-		return extractSummary(o, f)
+		return extractSummary(o, f), nil
 	case dto.MetricType_UNTYPED:
-		return extractUntyped(o, f)
+		return extractUntyped(o, f), nil
 	case dto.MetricType_HISTOGRAM:
-		return extractHistogram(o, f)
+		return extractHistogram(o, f), nil
 	}
-	panic("expfmt.extractSamples: unknown metric family type")
+	return nil, fmt.Errorf("expfmt.extractSamples: unknown metric family type %v", f.GetType())
 }
 
 func extractCounter(o *DecodeOptions, f *dto.MetricFamily) model.Vector {

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

@@ -11,14 +11,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// A package for reading and writing Prometheus metrics.
+// Package expfmt contains tools for reading and writing Prometheus metrics.
 package expfmt
 
+// Format specifies the HTTP content type of the different wire protocols.
 type Format string
 
+// Constants to assemble the Content-Type values for the different wire protocols.
 const (
-	TextVersion = "0.0.4"
-
+	TextVersion   = "0.0.4"
 	ProtoType     = `application/vnd.google.protobuf`
 	ProtoProtocol = `io.prometheus.client.MetricFamily`
 	ProtoFmt      = ProtoType + "; proto=" + ProtoProtocol + ";"

vendor/github.com/prometheus/common/log/syslog_formatter.go

@@ -23,6 +23,8 @@ import (
 	"github.com/Sirupsen/logrus"
 )
 
+var _ logrus.Formatter = (*syslogger)(nil)
+
 func init() {
 	setSyslogFormatter = func(appname, local string) error {
 		if appname == "" {
@@ -43,7 +45,7 @@ func init() {
 	}
 }
 
-var ceeTag = []byte("@cee:")
+var prefixTag []byte
 
 type syslogger struct {
 	wrap logrus.Formatter
@@ -56,6 +58,11 @@ func newSyslogger(appname string, facility string, fmter logrus.Formatter) (*sys
 		return nil, err
 	}
 	out, err := syslog.New(priority, appname)
+	_, isJSON := fmter.(*logrus.JSONFormatter)
+	if isJSON {
+		// add cee tag to json formatted syslogs
+		prefixTag = []byte("@cee:")
+	}
 	return &syslogger{
 		out:  out,
 		wrap: fmter,
@@ -92,7 +99,7 @@ func (s *syslogger) Format(e *logrus.Entry) ([]byte, error) {
 	}
 	// only append tag to data sent to syslog (line), not to what
 	// is returned
-	line := string(append(ceeTag, data...))
+	line := string(append(prefixTag, data...))
 
 	switch e.Level {
 	case logrus.PanicLevel:

vendor/github.com/prometheus/common/model/metric.go

@@ -44,7 +44,7 @@ func (m Metric) Before(o Metric) bool {
 
 // Clone returns a copy of the Metric.
 func (m Metric) Clone() Metric {
-	clone := Metric{}
+	clone := make(Metric, len(m))
 	for k, v := range m {
 		clone[k] = v
 	}

vendor/github.com/prometheus/common/model/value.go

@@ -129,11 +129,8 @@ func (s *Sample) Equal(o *Sample) bool {
 	if !s.Timestamp.Equal(o.Timestamp) {
 		return false
 	}
-	if s.Value.Equal(o.Value) {
-		return false
-	}
 
-	return true
+	return s.Value.Equal(o.Value)
 }
 
 func (s Sample) String() string {