git subrepo clone (merge) https://github.com/kubernetes-incubator/metrics-server.git metrics-server

subrepo:
  subdir:   "metrics-server"
  merged:   "92d8412"
upstream:
  origin:   "https://github.com/kubernetes-incubator/metrics-server.git"
  branch:   "master"
  commit:   "92d8412"
git-subrepo:
  version:  "0.4.0"
  origin:   "???"
  commit:   "???"
diff --git a/metrics-server/vendor/github.com/prometheus/common/model/labels.go b/metrics-server/vendor/github.com/prometheus/common/model/labels.go
new file mode 100644
index 0000000..41051a0
--- /dev/null
+++ b/metrics-server/vendor/github.com/prometheus/common/model/labels.go
@@ -0,0 +1,210 @@
+// Copyright 2013 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 model
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+)
+
+const (
+	// AlertNameLabel is the name of the label containing the an alert's name.
+	AlertNameLabel = "alertname"
+
+	// ExportedLabelPrefix is the prefix to prepend to the label names present in
+	// exported metrics if a label of the same name is added by the server.
+	ExportedLabelPrefix = "exported_"
+
+	// MetricNameLabel is the label name indicating the metric name of a
+	// timeseries.
+	MetricNameLabel = "__name__"
+
+	// SchemeLabel is the name of the label that holds the scheme on which to
+	// scrape a target.
+	SchemeLabel = "__scheme__"
+
+	// AddressLabel is the name of the label that holds the address of
+	// a scrape target.
+	AddressLabel = "__address__"
+
+	// MetricsPathLabel is the name of the label that holds the path on which to
+	// scrape a target.
+	MetricsPathLabel = "__metrics_path__"
+
+	// ReservedLabelPrefix is a prefix which is not legal in user-supplied
+	// label names.
+	ReservedLabelPrefix = "__"
+
+	// MetaLabelPrefix is a prefix for labels that provide meta information.
+	// Labels with this prefix are used for intermediate label processing and
+	// will not be attached to time series.
+	MetaLabelPrefix = "__meta_"
+
+	// TmpLabelPrefix is a prefix for temporary labels as part of relabelling.
+	// Labels with this prefix are used for intermediate label processing and
+	// will not be attached to time series. This is reserved for use in
+	// Prometheus configuration files by users.
+	TmpLabelPrefix = "__tmp_"
+
+	// ParamLabelPrefix is a prefix for labels that provide URL parameters
+	// used to scrape a target.
+	ParamLabelPrefix = "__param_"
+
+	// JobLabel is the label name indicating the job from which a timeseries
+	// was scraped.
+	JobLabel = "job"
+
+	// InstanceLabel is the label name used for the instance label.
+	InstanceLabel = "instance"
+
+	// BucketLabel is used for the label that defines the upper bound of a
+	// bucket of a histogram ("le" -> "less or equal").
+	BucketLabel = "le"
+
+	// QuantileLabel is used for the label that defines the quantile in a
+	// summary.
+	QuantileLabel = "quantile"
+)
+
+// 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. 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
+	}
+	for i, b := range ln {
+		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) {
+			return false
+		}
+	}
+	return true
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var s string
+	if err := unmarshal(&s); err != nil {
+		return err
+	}
+	if !LabelName(s).IsValid() {
+		return fmt.Errorf("%q is not a valid label name", s)
+	}
+	*ln = LabelName(s)
+	return nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (ln *LabelName) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	if !LabelName(s).IsValid() {
+		return fmt.Errorf("%q is not a valid label name", s)
+	}
+	*ln = LabelName(s)
+	return nil
+}
+
+// LabelNames is a sortable LabelName slice. In implements sort.Interface.
+type LabelNames []LabelName
+
+func (l LabelNames) Len() int {
+	return len(l)
+}
+
+func (l LabelNames) Less(i, j int) bool {
+	return l[i] < l[j]
+}
+
+func (l LabelNames) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
+
+func (l LabelNames) String() string {
+	labelStrings := make([]string, 0, len(l))
+	for _, label := range l {
+		labelStrings = append(labelStrings, string(label))
+	}
+	return strings.Join(labelStrings, ", ")
+}
+
+// A LabelValue is an associated value for a LabelName.
+type LabelValue string
+
+// IsValid returns true iff the string is a valid UTF8.
+func (lv LabelValue) IsValid() bool {
+	return utf8.ValidString(string(lv))
+}
+
+// LabelValues is a sortable LabelValue slice. It implements sort.Interface.
+type LabelValues []LabelValue
+
+func (l LabelValues) Len() int {
+	return len(l)
+}
+
+func (l LabelValues) Less(i, j int) bool {
+	return string(l[i]) < string(l[j])
+}
+
+func (l LabelValues) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
+
+// LabelPair pairs a name with a value.
+type LabelPair struct {
+	Name  LabelName
+	Value LabelValue
+}
+
+// LabelPairs is a sortable slice of LabelPair pointers. It implements
+// sort.Interface.
+type LabelPairs []*LabelPair
+
+func (l LabelPairs) Len() int {
+	return len(l)
+}
+
+func (l LabelPairs) Less(i, j int) bool {
+	switch {
+	case l[i].Name > l[j].Name:
+		return false
+	case l[i].Name < l[j].Name:
+		return true
+	case l[i].Value > l[j].Value:
+		return false
+	case l[i].Value < l[j].Value:
+		return true
+	default:
+		return false
+	}
+}
+
+func (l LabelPairs) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}