negroniprometheus

README

negroni-prometheus

Prometheus middleware for negroni.

This is a middleware by zbindenren that was adapted for use in Fresh8 Gaming Go services.

• The _total metric was removed as it is a duplicate of the histogram's _count
• Instead of the const label service we are now using namespace (our short company name) and subsystem (service name).
• The latency metric is now in microseconds instead of milliseconds

Why

Logging v. instrumentation

Instead of logging request times, it is considered best practice to provide an endpoint for instrumentation tools (like prometheus).

Usage

Use this middleware like the negroni.Logger middleware (after negroni.Recovery, before every other middleware).

Take a look at the example.

What do you get

An endpoint with the following information (stripped output):

...
# HELP negroni_request_duration_milliseconds How long it took to process the request, partitioned by status code, method and HTTP path.
# TYPE negroni_request_duration_milliseconds histogram
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/metrics",service="serviceName",le="300"} 1
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/metrics",service="serviceName",le="1200"} 1
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/metrics",service="serviceName",le="5000"} 1
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/metrics",service="serviceName",le="+Inf"} 1
negroni_request_duration_milliseconds_sum{code="OK",method="GET",path="/metrics",service="serviceName"} 2.003123
negroni_request_duration_milliseconds_count{code="OK",method="GET",path="/metrics",service="serviceName"} 1
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/ok",service="serviceName",le="300"} 0
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/ok",service="serviceName",le="1200"} 0
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/ok",service="serviceName",le="5000"} 2
negroni_request_duration_milliseconds_bucket{code="OK",method="GET",path="/ok",service="serviceName",le="+Inf"} 2
negroni_request_duration_milliseconds_sum{code="OK",method="GET",path="/ok",service="serviceName"} 4747.529026
negroni_request_duration_milliseconds_count{code="OK",method="GET",path="/ok",service="serviceName"} 2
...

Documentation

Index

• type Middleware
  • func NewMiddleware(group, name string, buckets ...float64) *Middleware
  • func (m *Middleware) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)

Types

type Middleware

type Middleware struct {
	// contains filtered or unexported fields
}

Middleware is a handler that exposes prometheus metrics for the number of requests, the latency and the response size, partitioned by status code, method and HTTP path.

func NewMiddleware

func NewMiddleware(group, name string, buckets ...float64) *Middleware

NewMiddleware returns a new prometheus Middleware handler.

func (*Middleware) ServeHTTP

func (m *Middleware) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)