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Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go')
-rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go new file mode 100644 index 000000000..86fd56447 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go @@ -0,0 +1,97 @@ +// 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 non-const non-curried labels. For +// those, the only allowed label names are "code" and "method". The function +// panics otherwise. 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 non-const +// non-curried labels. For those, the only allowed label names are "code" and +// "method". The function panics otherwise. 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. +// +// Note that this method is only guaranteed to never observe negative durations +// if used with Go1.9+. +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 + }) +} |