mirror of https://github.com/docker/cli.git
275 lines
8.5 KiB
Go
275 lines
8.5 KiB
Go
// Copyright 2014 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 prometheus
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"sort"
|
|
"time"
|
|
"unicode/utf8"
|
|
|
|
"github.com/prometheus/client_golang/prometheus/internal"
|
|
|
|
dto "github.com/prometheus/client_model/go"
|
|
"google.golang.org/protobuf/proto"
|
|
"google.golang.org/protobuf/types/known/timestamppb"
|
|
)
|
|
|
|
// ValueType is an enumeration of metric types that represent a simple value.
|
|
type ValueType int
|
|
|
|
// Possible values for the ValueType enum. Use UntypedValue to mark a metric
|
|
// with an unknown type.
|
|
const (
|
|
_ ValueType = iota
|
|
CounterValue
|
|
GaugeValue
|
|
UntypedValue
|
|
)
|
|
|
|
var (
|
|
CounterMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_COUNTER; return &d }()
|
|
GaugeMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_GAUGE; return &d }()
|
|
UntypedMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_UNTYPED; return &d }()
|
|
)
|
|
|
|
func (v ValueType) ToDTO() *dto.MetricType {
|
|
switch v {
|
|
case CounterValue:
|
|
return CounterMetricTypePtr
|
|
case GaugeValue:
|
|
return GaugeMetricTypePtr
|
|
default:
|
|
return UntypedMetricTypePtr
|
|
}
|
|
}
|
|
|
|
// valueFunc is a generic metric for simple values retrieved on collect time
|
|
// from a function. It implements Metric and Collector. Its effective type is
|
|
// determined by ValueType. This is a low-level building block used by the
|
|
// library to back the implementations of CounterFunc, GaugeFunc, and
|
|
// UntypedFunc.
|
|
type valueFunc struct {
|
|
selfCollector
|
|
|
|
desc *Desc
|
|
valType ValueType
|
|
function func() float64
|
|
labelPairs []*dto.LabelPair
|
|
}
|
|
|
|
// newValueFunc returns a newly allocated valueFunc with the given Desc and
|
|
// ValueType. The value reported is determined by calling the given function
|
|
// from within the Write method. Take into account that metric collection may
|
|
// happen concurrently. If that results in concurrent calls to Write, like in
|
|
// the case where a valueFunc is directly registered with Prometheus, the
|
|
// provided function must be concurrency-safe.
|
|
func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc {
|
|
result := &valueFunc{
|
|
desc: desc,
|
|
valType: valueType,
|
|
function: function,
|
|
labelPairs: MakeLabelPairs(desc, nil),
|
|
}
|
|
result.init(result)
|
|
return result
|
|
}
|
|
|
|
func (v *valueFunc) Desc() *Desc {
|
|
return v.desc
|
|
}
|
|
|
|
func (v *valueFunc) Write(out *dto.Metric) error {
|
|
return populateMetric(v.valType, v.function(), v.labelPairs, nil, out, nil)
|
|
}
|
|
|
|
// NewConstMetric returns a metric with one fixed value that cannot be
|
|
// changed. Users of this package will not have much use for it in regular
|
|
// operations. However, when implementing custom Collectors, it is useful as a
|
|
// throw-away metric that is generated on the fly to send it to Prometheus in
|
|
// the Collect method. NewConstMetric returns an error if the length of
|
|
// labelValues is not consistent with the variable labels in Desc or if Desc is
|
|
// invalid.
|
|
func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
|
|
if desc.err != nil {
|
|
return nil, desc.err
|
|
}
|
|
if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
metric := &dto.Metric{}
|
|
if err := populateMetric(valueType, value, MakeLabelPairs(desc, labelValues), nil, metric, nil); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &constMetric{
|
|
desc: desc,
|
|
metric: metric,
|
|
}, nil
|
|
}
|
|
|
|
// MustNewConstMetric is a version of NewConstMetric that panics where
|
|
// NewConstMetric would have returned an error.
|
|
func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
|
|
m, err := NewConstMetric(desc, valueType, value, labelValues...)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return m
|
|
}
|
|
|
|
// NewConstMetricWithCreatedTimestamp does the same thing as NewConstMetric, but generates Counters
|
|
// with created timestamp set and returns an error for other metric types.
|
|
func NewConstMetricWithCreatedTimestamp(desc *Desc, valueType ValueType, value float64, ct time.Time, labelValues ...string) (Metric, error) {
|
|
if desc.err != nil {
|
|
return nil, desc.err
|
|
}
|
|
if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
|
|
return nil, err
|
|
}
|
|
switch valueType {
|
|
case CounterValue:
|
|
break
|
|
default:
|
|
return nil, errors.New("created timestamps are only supported for counters")
|
|
}
|
|
|
|
metric := &dto.Metric{}
|
|
if err := populateMetric(valueType, value, MakeLabelPairs(desc, labelValues), nil, metric, timestamppb.New(ct)); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &constMetric{
|
|
desc: desc,
|
|
metric: metric,
|
|
}, nil
|
|
}
|
|
|
|
// MustNewConstMetricWithCreatedTimestamp is a version of NewConstMetricWithCreatedTimestamp that panics where
|
|
// NewConstMetricWithCreatedTimestamp would have returned an error.
|
|
func MustNewConstMetricWithCreatedTimestamp(desc *Desc, valueType ValueType, value float64, ct time.Time, labelValues ...string) Metric {
|
|
m, err := NewConstMetricWithCreatedTimestamp(desc, valueType, value, ct, labelValues...)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return m
|
|
}
|
|
|
|
type constMetric struct {
|
|
desc *Desc
|
|
metric *dto.Metric
|
|
}
|
|
|
|
func (m *constMetric) Desc() *Desc {
|
|
return m.desc
|
|
}
|
|
|
|
func (m *constMetric) Write(out *dto.Metric) error {
|
|
out.Label = m.metric.Label
|
|
out.Counter = m.metric.Counter
|
|
out.Gauge = m.metric.Gauge
|
|
out.Untyped = m.metric.Untyped
|
|
return nil
|
|
}
|
|
|
|
func populateMetric(
|
|
t ValueType,
|
|
v float64,
|
|
labelPairs []*dto.LabelPair,
|
|
e *dto.Exemplar,
|
|
m *dto.Metric,
|
|
ct *timestamppb.Timestamp,
|
|
) error {
|
|
m.Label = labelPairs
|
|
switch t {
|
|
case CounterValue:
|
|
m.Counter = &dto.Counter{Value: proto.Float64(v), Exemplar: e, CreatedTimestamp: ct}
|
|
case GaugeValue:
|
|
m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
|
|
case UntypedValue:
|
|
m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
|
|
default:
|
|
return fmt.Errorf("encountered unknown type %v", t)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// MakeLabelPairs is a helper function to create protobuf LabelPairs from the
|
|
// variable and constant labels in the provided Desc. The values for the
|
|
// variable labels are defined by the labelValues slice, which must be in the
|
|
// same order as the corresponding variable labels in the Desc.
|
|
//
|
|
// This function is only needed for custom Metric implementations. See MetricVec
|
|
// example.
|
|
func MakeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
|
|
totalLen := len(desc.variableLabels.names) + len(desc.constLabelPairs)
|
|
if totalLen == 0 {
|
|
// Super fast path.
|
|
return nil
|
|
}
|
|
if len(desc.variableLabels.names) == 0 {
|
|
// Moderately fast path.
|
|
return desc.constLabelPairs
|
|
}
|
|
labelPairs := make([]*dto.LabelPair, 0, totalLen)
|
|
for i, l := range desc.variableLabels.names {
|
|
labelPairs = append(labelPairs, &dto.LabelPair{
|
|
Name: proto.String(l),
|
|
Value: proto.String(labelValues[i]),
|
|
})
|
|
}
|
|
labelPairs = append(labelPairs, desc.constLabelPairs...)
|
|
sort.Sort(internal.LabelPairSorter(labelPairs))
|
|
return labelPairs
|
|
}
|
|
|
|
// ExemplarMaxRunes is the max total number of runes allowed in exemplar labels.
|
|
const ExemplarMaxRunes = 128
|
|
|
|
// newExemplar creates a new dto.Exemplar from the provided values. An error is
|
|
// returned if any of the label names or values are invalid or if the total
|
|
// number of runes in the label names and values exceeds ExemplarMaxRunes.
|
|
func newExemplar(value float64, ts time.Time, l Labels) (*dto.Exemplar, error) {
|
|
e := &dto.Exemplar{}
|
|
e.Value = proto.Float64(value)
|
|
tsProto := timestamppb.New(ts)
|
|
if err := tsProto.CheckValid(); err != nil {
|
|
return nil, err
|
|
}
|
|
e.Timestamp = tsProto
|
|
labelPairs := make([]*dto.LabelPair, 0, len(l))
|
|
var runes int
|
|
for name, value := range l {
|
|
if !checkLabelName(name) {
|
|
return nil, fmt.Errorf("exemplar label name %q is invalid", name)
|
|
}
|
|
runes += utf8.RuneCountInString(name)
|
|
if !utf8.ValidString(value) {
|
|
return nil, fmt.Errorf("exemplar label value %q is not valid UTF-8", value)
|
|
}
|
|
runes += utf8.RuneCountInString(value)
|
|
labelPairs = append(labelPairs, &dto.LabelPair{
|
|
Name: proto.String(name),
|
|
Value: proto.String(value),
|
|
})
|
|
}
|
|
if runes > ExemplarMaxRunes {
|
|
return nil, fmt.Errorf("exemplar labels have %d runes, exceeding the limit of %d", runes, ExemplarMaxRunes)
|
|
}
|
|
e.Label = labelPairs
|
|
return e, nil
|
|
}
|