distribution/vendor/github.com/docker/go-metrics/namespace.go
tifayuki e3c37a46e2 Add Prometheus Metrics
at the first iteration, only the following metrics are collected:

  - HTTP metrics of each API endpoint
  - cache counter for request/hit/miss
  - histogram of storage actions, including:
    GetContent, PutContent, Stat, List, Move, and Delete

Signed-off-by: tifayuki <tifayuki@gmail.com>
2018-02-09 14:27:51 -08:00

315 lines
8.7 KiB
Go

package metrics
import (
"fmt"
"sync"
"github.com/prometheus/client_golang/prometheus"
)
type Labels map[string]string
// NewNamespace returns a namespaces that is responsible for managing a collection of
// metrics for a particual namespace and subsystem
//
// labels allows const labels to be added to all metrics created in this namespace
// and are commonly used for data like application version and git commit
func NewNamespace(name, subsystem string, labels Labels) *Namespace {
if labels == nil {
labels = make(map[string]string)
}
return &Namespace{
name: name,
subsystem: subsystem,
labels: labels,
}
}
// Namespace describes a set of metrics that share a namespace and subsystem.
type Namespace struct {
name string
subsystem string
labels Labels
mu sync.Mutex
metrics []prometheus.Collector
}
// WithConstLabels returns a namespace with the provided set of labels merged
// with the existing constant labels on the namespace.
//
// Only metrics created with the returned namespace will get the new constant
// labels. The returned namespace must be registered separately.
func (n *Namespace) WithConstLabels(labels Labels) *Namespace {
n.mu.Lock()
ns := &Namespace{
name: n.name,
subsystem: n.subsystem,
labels: mergeLabels(n.labels, labels),
}
n.mu.Unlock()
return ns
}
func (n *Namespace) NewCounter(name, help string) Counter {
c := &counter{pc: prometheus.NewCounter(n.newCounterOpts(name, help))}
n.Add(c)
return c
}
func (n *Namespace) NewLabeledCounter(name, help string, labels ...string) LabeledCounter {
c := &labeledCounter{pc: prometheus.NewCounterVec(n.newCounterOpts(name, help), labels)}
n.Add(c)
return c
}
func (n *Namespace) newCounterOpts(name, help string) prometheus.CounterOpts {
return prometheus.CounterOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: makeName(name, Total),
Help: help,
ConstLabels: prometheus.Labels(n.labels),
}
}
func (n *Namespace) NewTimer(name, help string) Timer {
t := &timer{
m: prometheus.NewHistogram(n.newTimerOpts(name, help)),
}
n.Add(t)
return t
}
func (n *Namespace) NewLabeledTimer(name, help string, labels ...string) LabeledTimer {
t := &labeledTimer{
m: prometheus.NewHistogramVec(n.newTimerOpts(name, help), labels),
}
n.Add(t)
return t
}
func (n *Namespace) newTimerOpts(name, help string) prometheus.HistogramOpts {
return prometheus.HistogramOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: makeName(name, Seconds),
Help: help,
ConstLabels: prometheus.Labels(n.labels),
}
}
func (n *Namespace) NewGauge(name, help string, unit Unit) Gauge {
g := &gauge{
pg: prometheus.NewGauge(n.newGaugeOpts(name, help, unit)),
}
n.Add(g)
return g
}
func (n *Namespace) NewLabeledGauge(name, help string, unit Unit, labels ...string) LabeledGauge {
g := &labeledGauge{
pg: prometheus.NewGaugeVec(n.newGaugeOpts(name, help, unit), labels),
}
n.Add(g)
return g
}
func (n *Namespace) newGaugeOpts(name, help string, unit Unit) prometheus.GaugeOpts {
return prometheus.GaugeOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: makeName(name, unit),
Help: help,
ConstLabels: prometheus.Labels(n.labels),
}
}
func (n *Namespace) Describe(ch chan<- *prometheus.Desc) {
n.mu.Lock()
defer n.mu.Unlock()
for _, metric := range n.metrics {
metric.Describe(ch)
}
}
func (n *Namespace) Collect(ch chan<- prometheus.Metric) {
n.mu.Lock()
defer n.mu.Unlock()
for _, metric := range n.metrics {
metric.Collect(ch)
}
}
func (n *Namespace) Add(collector prometheus.Collector) {
n.mu.Lock()
n.metrics = append(n.metrics, collector)
n.mu.Unlock()
}
func (n *Namespace) NewDesc(name, help string, unit Unit, labels ...string) *prometheus.Desc {
name = makeName(name, unit)
namespace := n.name
if n.subsystem != "" {
namespace = fmt.Sprintf("%s_%s", namespace, n.subsystem)
}
name = fmt.Sprintf("%s_%s", namespace, name)
return prometheus.NewDesc(name, help, labels, prometheus.Labels(n.labels))
}
// mergeLabels merges two or more labels objects into a single map, favoring
// the later labels.
func mergeLabels(lbs ...Labels) Labels {
merged := make(Labels)
for _, target := range lbs {
for k, v := range target {
merged[k] = v
}
}
return merged
}
func makeName(name string, unit Unit) string {
if unit == "" {
return name
}
return fmt.Sprintf("%s_%s", name, unit)
}
func (n *Namespace) NewDefaultHttpMetrics(handlerName string) []*HTTPMetric {
return n.NewHttpMetricsWithOpts(handlerName, HTTPHandlerOpts{
DurationBuckets: defaultDurationBuckets,
RequestSizeBuckets: defaultResponseSizeBuckets,
ResponseSizeBuckets: defaultResponseSizeBuckets,
})
}
func (n *Namespace) NewHttpMetrics(handlerName string, durationBuckets, requestSizeBuckets, responseSizeBuckets []float64) []*HTTPMetric {
return n.NewHttpMetricsWithOpts(handlerName, HTTPHandlerOpts{
DurationBuckets: durationBuckets,
RequestSizeBuckets: requestSizeBuckets,
ResponseSizeBuckets: responseSizeBuckets,
})
}
func (n *Namespace) NewHttpMetricsWithOpts(handlerName string, opts HTTPHandlerOpts) []*HTTPMetric {
var httpMetrics []*HTTPMetric
inFlightMetric := n.NewInFlightGaugeMetric(handlerName)
requestTotalMetric := n.NewRequestTotalMetric(handlerName)
requestDurationMetric := n.NewRequestDurationMetric(handlerName, opts.DurationBuckets)
requestSizeMetric := n.NewRequestSizeMetric(handlerName, opts.RequestSizeBuckets)
responseSizeMetric := n.NewResponseSizeMetric(handlerName, opts.ResponseSizeBuckets)
httpMetrics = append(httpMetrics, inFlightMetric, requestDurationMetric, requestTotalMetric, requestSizeMetric, responseSizeMetric)
return httpMetrics
}
func (n *Namespace) NewInFlightGaugeMetric(handlerName string) *HTTPMetric {
labels := prometheus.Labels(n.labels)
labels["handler"] = handlerName
metric := prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: "in_flight_requests",
Help: "The in-flight HTTP requests",
ConstLabels: prometheus.Labels(labels),
})
httpMetric := &HTTPMetric{
Collector: metric,
handlerType: InstrumentHandlerInFlight,
}
n.Add(httpMetric)
return httpMetric
}
func (n *Namespace) NewRequestTotalMetric(handlerName string) *HTTPMetric {
labels := prometheus.Labels(n.labels)
labels["handler"] = handlerName
metric := prometheus.NewCounterVec(
prometheus.CounterOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: "requests_total",
Help: "Total number of HTTP requests made.",
ConstLabels: prometheus.Labels(labels),
},
[]string{"code", "method"},
)
httpMetric := &HTTPMetric{
Collector: metric,
handlerType: InstrumentHandlerCounter,
}
n.Add(httpMetric)
return httpMetric
}
func (n *Namespace) NewRequestDurationMetric(handlerName string, buckets []float64) *HTTPMetric {
if len(buckets) == 0 {
panic("DurationBuckets must be provided")
}
labels := prometheus.Labels(n.labels)
labels["handler"] = handlerName
opts := prometheus.HistogramOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: "request_duration_seconds",
Help: "The HTTP request latencies in seconds.",
Buckets: buckets,
ConstLabels: prometheus.Labels(labels),
}
metric := prometheus.NewHistogramVec(opts, []string{"method"})
httpMetric := &HTTPMetric{
Collector: metric,
handlerType: InstrumentHandlerDuration,
}
n.Add(httpMetric)
return httpMetric
}
func (n *Namespace) NewRequestSizeMetric(handlerName string, buckets []float64) *HTTPMetric {
if len(buckets) == 0 {
panic("RequestSizeBuckets must be provided")
}
labels := prometheus.Labels(n.labels)
labels["handler"] = handlerName
opts := prometheus.HistogramOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: "request_size_bytes",
Help: "The HTTP request sizes in bytes.",
Buckets: buckets,
ConstLabels: prometheus.Labels(labels),
}
metric := prometheus.NewHistogramVec(opts, []string{})
httpMetric := &HTTPMetric{
Collector: metric,
handlerType: InstrumentHandlerRequestSize,
}
n.Add(httpMetric)
return httpMetric
}
func (n *Namespace) NewResponseSizeMetric(handlerName string, buckets []float64) *HTTPMetric {
if len(buckets) == 0 {
panic("ResponseSizeBuckets must be provided")
}
labels := prometheus.Labels(n.labels)
labels["handler"] = handlerName
opts := prometheus.HistogramOpts{
Namespace: n.name,
Subsystem: n.subsystem,
Name: "response_size_bytes",
Help: "The HTTP response sizes in bytes.",
Buckets: buckets,
ConstLabels: prometheus.Labels(labels),
}
metrics := prometheus.NewHistogramVec(opts, []string{})
httpMetric := &HTTPMetric{
Collector: metrics,
handlerType: InstrumentHandlerResponseSize,
}
n.Add(httpMetric)
return httpMetric
}