Instrument RoundTripper via middleware (#295)
Instrument RoundTripper via middleware
This commit is contained in:
stuart nelson
Björn Rabenstein
parent
7d9484283e
commit
d300d5cf21
|
|
@ -4,6 +4,7 @@ language: go
|
|||
go:
|
||||
- 1.6.3
|
||||
- 1.7
|
||||
- 1.8.1
|
||||
|
||||
script:
|
||||
- go test -short ./...
|
||||
- go test -short ./...
|
||||
|
|
|
|||
|
|
@ -24,6 +24,11 @@
|
|||
// via middleware. Middleware wrappers follow the naming scheme
|
||||
// InstrumentHandlerX, where X describes the intended use of the middleware.
|
||||
// See each function's doc comment for specific details.
|
||||
//
|
||||
// Finally, the package allows for an http.RoundTripper to be instrumented via
|
||||
// middleware. Middleware wrappers follow the naming scheme
|
||||
// InstrumentRoundTripperX, where X describes the intended use of the
|
||||
// middleware. See each function's doc comment for specific details.
|
||||
package promhttp
|
||||
|
||||
import (
|
||||
|
|
|
|||
|
|
@ -0,0 +1,95 @@
|
|||
// Copyright 2017 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 promhttp
|
||||
|
||||
import (
|
||||
"net/http"
|
||||
"time"
|
||||
|
||||
"github.com/prometheus/client_golang/prometheus"
|
||||
)
|
||||
|
||||
// The RoundTripperFunc type is an adapter to allow the use of ordinary
|
||||
// functions as RoundTrippers. If f is a function with the appropriate
|
||||
// signature, RountTripperFunc(f) is a RoundTripper that calls f.
|
||||
type RoundTripperFunc func(req *http.Request) (*http.Response, error)
|
||||
|
||||
// RoundTrip implements the RoundTripper interface.
|
||||
func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
|
||||
return rt(r)
|
||||
}
|
||||
|
||||
// InstrumentRoundTripperInFlight is a middleware that wraps the provided
|
||||
// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
|
||||
// requests currently handled by the wrapped http.RoundTripper.
|
||||
//
|
||||
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
|
||||
func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
|
||||
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
|
||||
gauge.Inc()
|
||||
defer gauge.Dec()
|
||||
return next.RoundTrip(r)
|
||||
})
|
||||
}
|
||||
|
||||
// InstrumentRoundTripperCounter is a middleware that wraps the provided
|
||||
// http.RoundTripper to observe the request result with the provided CounterVec.
|
||||
// The CounterVec must have zero, one, or two labels. The only allowed label
|
||||
// names are "code" and "method". The function panics if any other instance
|
||||
// labels are provided. Partitioning of the CounterVec happens by HTTP status
|
||||
// code and/or HTTP method if the respective instance label names are present
|
||||
// in the CounterVec. For unpartitioned counting, use a CounterVec with
|
||||
// zero labels.
|
||||
//
|
||||
// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
|
||||
// is not incremented.
|
||||
//
|
||||
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
|
||||
func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper) RoundTripperFunc {
|
||||
code, method := checkLabels(counter)
|
||||
|
||||
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
|
||||
resp, err := next.RoundTrip(r)
|
||||
if err == nil {
|
||||
counter.With(labels(code, method, r.Method, resp.StatusCode)).Inc()
|
||||
}
|
||||
return resp, err
|
||||
})
|
||||
}
|
||||
|
||||
// InstrumentRoundTripperDuration is a middleware that wraps the provided
|
||||
// http.RoundTripper to observe the request duration with the provided ObserverVec.
|
||||
// The ObserverVec must have zero, one, or two labels. The only allowed label
|
||||
// names are "code" and "method". The function panics if any other instance
|
||||
// labels are provided. The Observe method of the Observer in the ObserverVec
|
||||
// is called with the request duration in seconds. Partitioning happens by HTTP
|
||||
// status code and/or HTTP method if the respective instance label names are
|
||||
// present in the ObserverVec. For unpartitioned observations, use an
|
||||
// ObserverVec with zero labels. Note that partitioning of Histograms is
|
||||
// expensive and should be used judiciously.
|
||||
//
|
||||
// If the wrapped RoundTripper panics or returns a non-nil error, no values are
|
||||
// reported.
|
||||
func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper) RoundTripperFunc {
|
||||
code, method := checkLabels(obs)
|
||||
|
||||
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
|
||||
start := time.Now()
|
||||
resp, err := next.RoundTrip(r)
|
||||
if err == nil {
|
||||
obs.With(labels(code, method, r.Method, resp.StatusCode)).Observe(time.Since(start).Seconds())
|
||||
}
|
||||
return resp, err
|
||||
})
|
||||
}
|
||||
|
|
@ -0,0 +1,142 @@
|
|||
// Copyright 2017 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.
|
||||
|
||||
// +build go1.8
|
||||
|
||||
package promhttp
|
||||
|
||||
import (
|
||||
"context"
|
||||
"crypto/tls"
|
||||
"net/http"
|
||||
"net/http/httptrace"
|
||||
"time"
|
||||
)
|
||||
|
||||
// InstrumentTrace is used to offer flexibility in instrumenting the available
|
||||
// httptrace.ClientTrace hook functions. Each function is passed a float64
|
||||
// representing the time in seconds since the start of the http request. A user
|
||||
// may choose to use separately buckets Histograms, or implement custom
|
||||
// instance labels on a per function basis.
|
||||
type InstrumentTrace struct {
|
||||
GotConn func(float64)
|
||||
PutIdleConn func(float64)
|
||||
GotFirstResponseByte func(float64)
|
||||
Got100Continue func(float64)
|
||||
DNSStart func(float64)
|
||||
DNSDone func(float64)
|
||||
ConnectStart func(float64)
|
||||
ConnectDone func(float64)
|
||||
TLSHandshakeStart func(float64)
|
||||
TLSHandshakeDone func(float64)
|
||||
WroteHeaders func(float64)
|
||||
Wait100Continue func(float64)
|
||||
WroteRequest func(float64)
|
||||
}
|
||||
|
||||
// InstrumentRoundTripperTrace is a middleware that wraps the provided
|
||||
// RoundTripper and reports times to hook functions provided in the
|
||||
// InstrumentTrace struct. Hook functions that are not present in the provided
|
||||
// InstrumentTrace struct are ignored. Times reported to the hook functions are
|
||||
// time since the start of the request. Note that partitioning of Histograms
|
||||
// is expensive and should be used judiciously.
|
||||
//
|
||||
// For hook functions that receive an error as an argument, no observations are
|
||||
// made in the event of a non-nil error value.
|
||||
//
|
||||
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
|
||||
func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
|
||||
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
|
||||
start := time.Now()
|
||||
|
||||
trace := &httptrace.ClientTrace{
|
||||
GotConn: func(_ httptrace.GotConnInfo) {
|
||||
if it.GotConn != nil {
|
||||
it.GotConn(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
PutIdleConn: func(err error) {
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
if it.PutIdleConn != nil {
|
||||
it.PutIdleConn(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
DNSStart: func(_ httptrace.DNSStartInfo) {
|
||||
if it.DNSStart != nil {
|
||||
it.DNSStart(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
DNSDone: func(_ httptrace.DNSDoneInfo) {
|
||||
if it.DNSStart != nil {
|
||||
it.DNSStart(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
ConnectStart: func(_, _ string) {
|
||||
if it.ConnectStart != nil {
|
||||
it.ConnectStart(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
ConnectDone: func(_, _ string, err error) {
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
if it.ConnectDone != nil {
|
||||
it.ConnectDone(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
GotFirstResponseByte: func() {
|
||||
if it.GotFirstResponseByte != nil {
|
||||
it.GotFirstResponseByte(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
Got100Continue: func() {
|
||||
if it.Got100Continue != nil {
|
||||
it.Got100Continue(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
TLSHandshakeStart: func() {
|
||||
if it.TLSHandshakeStart != nil {
|
||||
it.TLSHandshakeStart(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
if it.TLSHandshakeDone != nil {
|
||||
it.TLSHandshakeDone(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
WroteHeaders: func() {
|
||||
if it.WroteHeaders != nil {
|
||||
it.WroteHeaders(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
Wait100Continue: func() {
|
||||
if it.Wait100Continue != nil {
|
||||
it.Wait100Continue(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
WroteRequest: func(_ httptrace.WroteRequestInfo) {
|
||||
if it.WroteRequest != nil {
|
||||
it.WroteRequest(time.Since(start).Seconds())
|
||||
}
|
||||
},
|
||||
}
|
||||
r = r.WithContext(httptrace.WithClientTrace(context.Background(), trace))
|
||||
|
||||
return next.RoundTrip(r)
|
||||
})
|
||||
}
|
||||
|
|
@ -0,0 +1,193 @@
|
|||
// Copyright 2017 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.
|
||||
|
||||
// +build go1.8
|
||||
|
||||
package promhttp
|
||||
|
||||
import (
|
||||
"log"
|
||||
"net/http"
|
||||
"testing"
|
||||
"time"
|
||||
|
||||
"github.com/prometheus/client_golang/prometheus"
|
||||
)
|
||||
|
||||
func TestClientMiddlewareAPI(t *testing.T) {
|
||||
client := http.DefaultClient
|
||||
client.Timeout = 1 * time.Second
|
||||
|
||||
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
|
||||
Name: "client_in_flight_requests",
|
||||
Help: "A gauge of in-flight requests for the wrapped client.",
|
||||
})
|
||||
|
||||
counter := prometheus.NewCounterVec(
|
||||
prometheus.CounterOpts{
|
||||
Name: "client_api_requests_total",
|
||||
Help: "A counter for requests from the wrapped client.",
|
||||
},
|
||||
[]string{"code", "method"},
|
||||
)
|
||||
|
||||
dnsLatencyVec := prometheus.NewHistogramVec(
|
||||
prometheus.HistogramOpts{
|
||||
Name: "dns_duration_seconds",
|
||||
Help: "Trace dns latency histogram.",
|
||||
Buckets: []float64{.005, .01, .025, .05},
|
||||
},
|
||||
[]string{"event"},
|
||||
)
|
||||
|
||||
tlsLatencyVec := prometheus.NewHistogramVec(
|
||||
prometheus.HistogramOpts{
|
||||
Name: "tls_duration_seconds",
|
||||
Help: "Trace tls latency histogram.",
|
||||
Buckets: []float64{.05, .1, .25, .5},
|
||||
},
|
||||
[]string{"event"},
|
||||
)
|
||||
|
||||
histVec := prometheus.NewHistogramVec(
|
||||
prometheus.HistogramOpts{
|
||||
Name: "request_duration_seconds",
|
||||
Help: "A histogram of request latencies.",
|
||||
Buckets: prometheus.DefBuckets,
|
||||
},
|
||||
[]string{"method"},
|
||||
)
|
||||
|
||||
prometheus.MustRegister(counter, tlsLatencyVec, dnsLatencyVec, histVec, inFlightGauge)
|
||||
|
||||
trace := &InstrumentTrace{
|
||||
DNSStart: func(t float64) {
|
||||
dnsLatencyVec.WithLabelValues("dns_start")
|
||||
},
|
||||
DNSDone: func(t float64) {
|
||||
dnsLatencyVec.WithLabelValues("dns_done")
|
||||
},
|
||||
TLSHandshakeStart: func(t float64) {
|
||||
tlsLatencyVec.WithLabelValues("tls_handshake_start")
|
||||
},
|
||||
TLSHandshakeDone: func(t float64) {
|
||||
tlsLatencyVec.WithLabelValues("tls_handshake_done")
|
||||
},
|
||||
}
|
||||
|
||||
client.Transport = InstrumentRoundTripperInFlight(inFlightGauge,
|
||||
InstrumentRoundTripperCounter(counter,
|
||||
InstrumentRoundTripperTrace(trace,
|
||||
InstrumentRoundTripperDuration(histVec, http.DefaultTransport),
|
||||
),
|
||||
),
|
||||
)
|
||||
|
||||
resp, err := client.Get("http://google.com")
|
||||
if err != nil {
|
||||
t.Fatalf("%v", err)
|
||||
}
|
||||
defer resp.Body.Close()
|
||||
}
|
||||
|
||||
func ExampleInstrumentRoundTripperDuration() {
|
||||
client := http.DefaultClient
|
||||
client.Timeout = 1 * time.Second
|
||||
|
||||
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
|
||||
Name: "client_in_flight_requests",
|
||||
Help: "A gauge of in-flight requests for the wrapped client.",
|
||||
})
|
||||
|
||||
counter := prometheus.NewCounterVec(
|
||||
prometheus.CounterOpts{
|
||||
Name: "client_api_requests_total",
|
||||
Help: "A counter for requests from the wrapped client.",
|
||||
},
|
||||
[]string{"code", "method"},
|
||||
)
|
||||
|
||||
// dnsLatencyVec uses custom buckets based on expected dns durations.
|
||||
// It has an instance label "event", which is set in the
|
||||
// DNSStart and DNSDonehook functions defined in the
|
||||
// InstrumentTrace struct below.
|
||||
dnsLatencyVec := prometheus.NewHistogramVec(
|
||||
prometheus.HistogramOpts{
|
||||
Name: "dns_duration_seconds",
|
||||
Help: "Trace dns latency histogram.",
|
||||
Buckets: []float64{.005, .01, .025, .05},
|
||||
},
|
||||
[]string{"event"},
|
||||
)
|
||||
|
||||
// tlsLatencyVec uses custom buckets based on expected tls durations.
|
||||
// It has an instance label "event", which is set in the
|
||||
// TLSHandshakeStart and TLSHandshakeDone hook functions defined in the
|
||||
// InstrumentTrace struct below.
|
||||
tlsLatencyVec := prometheus.NewHistogramVec(
|
||||
prometheus.HistogramOpts{
|
||||
Name: "tls_duration_seconds",
|
||||
Help: "Trace tls latency histogram.",
|
||||
Buckets: []float64{.05, .1, .25, .5},
|
||||
},
|
||||
[]string{"event"},
|
||||
)
|
||||
|
||||
// histVec has no labels, making it a zero-dimensional ObserverVec.
|
||||
histVec := prometheus.NewHistogramVec(
|
||||
prometheus.HistogramOpts{
|
||||
Name: "request_duration_seconds",
|
||||
Help: "A histogram of request latencies.",
|
||||
Buckets: prometheus.DefBuckets,
|
||||
},
|
||||
[]string{},
|
||||
)
|
||||
|
||||
// Register all of the metrics in the standard registry.
|
||||
prometheus.MustRegister(counter, tlsLatencyVec, dnsLatencyVec, histVec, inFlightGauge)
|
||||
|
||||
// Define functions for the available httptrace.ClientTrace hook
|
||||
// functions that we want to instrument.
|
||||
trace := &InstrumentTrace{
|
||||
DNSStart: func(t float64) {
|
||||
dnsLatencyVec.WithLabelValues("dns_start")
|
||||
},
|
||||
DNSDone: func(t float64) {
|
||||
dnsLatencyVec.WithLabelValues("dns_done")
|
||||
},
|
||||
TLSHandshakeStart: func(t float64) {
|
||||
tlsLatencyVec.WithLabelValues("tls_handshake_start")
|
||||
},
|
||||
TLSHandshakeDone: func(t float64) {
|
||||
tlsLatencyVec.WithLabelValues("tls_handshake_done")
|
||||
},
|
||||
}
|
||||
|
||||
// Wrap the default RoundTripper with middleware.
|
||||
roundTripper := InstrumentRoundTripperInFlight(inFlightGauge,
|
||||
InstrumentRoundTripperCounter(counter,
|
||||
InstrumentRoundTripperTrace(trace,
|
||||
InstrumentRoundTripperDuration(histVec, http.DefaultTransport),
|
||||
),
|
||||
),
|
||||
)
|
||||
|
||||
// Set the RoundTripper on our client.
|
||||
client.Transport = roundTripper
|
||||
|
||||
resp, err := client.Get("http://google.com")
|
||||
if err != nil {
|
||||
log.Printf("error: %v", err)
|
||||
}
|
||||
defer resp.Body.Close()
|
||||
}
|
||||
|
|
@ -80,7 +80,7 @@ func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) ht
|
|||
// names are "code" and "method". The function panics if any other instance
|
||||
// labels are provided. Partitioning of the CounterVec happens by HTTP status
|
||||
// code and/or HTTP method if the respective instance label names are present
|
||||
// in the CounterVec. For unpartitioned observations, use a CounterVec with
|
||||
// in the CounterVec. For unpartitioned counting, use a CounterVec with
|
||||
// zero labels.
|
||||
//
|
||||
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
|
||||
|
|
|
|||
Loading…
Reference in New Issue