vendoring: Update prometheus/common to pull in bug fixes

In particular the one for https://github.com/prometheus/common/issues/72.

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/labels.go

@@ -80,14 +80,18 @@ const (
 	QuantileLabel = "quantile"
 )
 
-// LabelNameRE is a regular expression matching valid label names.
+// LabelNameRE is a regular expression matching valid label names. Note that the
+// IsValid method of LabelName performs the same check but faster than a match
+// with this regular expression.
 var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
 
 // A LabelName is a key for a LabelSet or Metric.  It has a value associated
 // therewith.
 type LabelName string
 
-// IsValid is true iff the label name matches the pattern of LabelNameRE.
+// IsValid is true iff the label name matches the pattern of LabelNameRE. This
+// method, however, does not use LabelNameRE for the check but a much faster
+// hardcoded implementation.
 func (ln LabelName) IsValid() bool {
 	if len(ln) == 0 {
 		return false
@@ -106,7 +110,7 @@ func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	if err := unmarshal(&s); err != nil {
 		return err
 	}
-	if !LabelNameRE.MatchString(s) {
+	if !LabelName(s).IsValid() {
 		return fmt.Errorf("%q is not a valid label name", s)
 	}
 	*ln = LabelName(s)
@@ -119,7 +123,7 @@ func (ln *LabelName) UnmarshalJSON(b []byte) error {
 	if err := json.Unmarshal(b, &s); err != nil {
 		return err
 	}
-	if !LabelNameRE.MatchString(s) {
+	if !LabelName(s).IsValid() {
 		return fmt.Errorf("%q is not a valid label name", s)
 	}
 	*ln = LabelName(s)

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

@@ -160,7 +160,7 @@ func (l *LabelSet) UnmarshalJSON(b []byte) error {
 	// LabelName as a string and does not call its UnmarshalJSON method.
 	// Thus, we have to replicate the behavior here.
 	for ln := range m {
-		if !LabelNameRE.MatchString(string(ln)) {
+		if !ln.IsValid() {
 			return fmt.Errorf("%q is not a valid label name", ln)
 		}
 	}

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

@@ -21,8 +21,11 @@ import (
 )
 
 var (
-	separator    = []byte{0}
-	MetricNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_:]*$`)
+	separator = []byte{0}
+	// MetricNameRE is a regular expression matching valid metric
+	// names. Note that the IsValidMetricName function performs the same
+	// check but faster than a match with this regular expression.
+	MetricNameRE = regexp.MustCompile(`^[a-zA-Z_:][a-zA-Z0-9_:]*$`)
 )
 
 // A Metric is similar to a LabelSet, but the key difference is that a Metric is
@@ -41,7 +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
 	}
@@ -85,6 +88,8 @@ func (m Metric) FastFingerprint() Fingerprint {
 }
 
 // IsValidMetricName returns true iff name matches the pattern of MetricNameRE.
+// This function, however, does not use MetricNameRE for the check but a much
+// faster hardcoded implementation.
 func IsValidMetricName(n LabelValue) bool {
 	if len(n) == 0 {
 		return false

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

@@ -33,18 +33,19 @@ func WithParam(ctx context.Context, p, v string) context.Context {
 	return context.WithValue(ctx, param(p), v)
 }
 
-type contextFn func(r *http.Request) (context.Context, error)
+// ContextFunc returns a new context for a request.
+type ContextFunc func(r *http.Request) (context.Context, error)
 
 // Router wraps httprouter.Router and adds support for prefixed sub-routers
 // and per-request context injections.
 type Router struct {
 	rtr    *httprouter.Router
 	prefix string
-	ctxFn  contextFn
+	ctxFn  ContextFunc
 }
 
 // New returns a new Router.
-func New(ctxFn contextFn) *Router {
+func New(ctxFn ContextFunc) *Router {
 	if ctxFn == nil {
 		ctxFn = func(r *http.Request) (context.Context, error) {
 			return context.Background(), nil

vendor/vendor.json

@@ -540,40 +540,40 @@
 			"revisionTime": "2015-02-12T10:17:44Z"
 		},
 		{
-			"checksumSHA1": "mHyjbJ3BWOfUV6q9f5PBt0gaY1k=",
+			"checksumSHA1": "jG8qYuDUuaZeflt4JxBBdyQBsXw=",
 			"path": "github.com/prometheus/common/expfmt",
-			"revision": "85637ea67b04b5c3bb25e671dacded2977f8f9f6",
-			"revisionTime": "2016-10-02T21:02:34Z"
+			"revision": "dd2f054febf4a6c00f2343686efb775948a8bff4",
+			"revisionTime": "2017-01-08T23:12:12Z"
 		},
 		{
 			"checksumSHA1": "GWlM3d2vPYyNATtTFgftS10/A9w=",
 			"path": "github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg",
-			"revision": "85637ea67b04b5c3bb25e671dacded2977f8f9f6",
-			"revisionTime": "2016-10-02T21:02:34Z"
+			"revision": "dd2f054febf4a6c00f2343686efb775948a8bff4",
+			"revisionTime": "2017-01-08T23:12:12Z"
 		},
 		{
-			"checksumSHA1": "UU6hIfhVjnAYDADQEfE/3T7Ddm8=",
+			"checksumSHA1": "ZA4MLHNAP905WiAOLy4BBzmcuxM=",
 			"path": "github.com/prometheus/common/log",
-			"revision": "85637ea67b04b5c3bb25e671dacded2977f8f9f6",
-			"revisionTime": "2016-10-02T21:02:34Z"
+			"revision": "dd2f054febf4a6c00f2343686efb775948a8bff4",
+			"revisionTime": "2017-01-08T23:12:12Z"
 		},
 		{
-			"checksumSHA1": "nFie+rxcX5WdIv1diZ+fu3aj6lE=",
+			"checksumSHA1": "vopCLXHzYm+3l5fPKOf4/fQwrCM=",
 			"path": "github.com/prometheus/common/model",
-			"revision": "85637ea67b04b5c3bb25e671dacded2977f8f9f6",
-			"revisionTime": "2016-10-02T21:02:34Z"
+			"revision": "dd2f054febf4a6c00f2343686efb775948a8bff4",
+			"revisionTime": "2017-01-08T23:12:12Z"
 		},
 		{
-			"checksumSHA1": "QQKJYoGcY10nIHxhBEHwjwUZQzk=",
+			"checksumSHA1": "ZbbESWBHHcPUJ/A5yrzKhTHuPc8=",
 			"path": "github.com/prometheus/common/route",
-			"revision": "85637ea67b04b5c3bb25e671dacded2977f8f9f6",
-			"revisionTime": "2016-10-02T21:02:34Z"
+			"revision": "dd2f054febf4a6c00f2343686efb775948a8bff4",
+			"revisionTime": "2017-01-08T23:12:12Z"
 		},
 		{
 			"checksumSHA1": "91KYK0SpvkaMJJA2+BcxbVnyRO0=",
 			"path": "github.com/prometheus/common/version",
-			"revision": "85637ea67b04b5c3bb25e671dacded2977f8f9f6",
-			"revisionTime": "2016-10-02T21:02:34Z"
+			"revision": "dd2f054febf4a6c00f2343686efb775948a8bff4",
+			"revisionTime": "2017-01-08T23:12:12Z"
 		},
 		{
 			"checksumSHA1": "W218eJZPXJG783fUr/z6IaAZyes=",