middleware

Documentation

Index

• func CorrelationId(config *correlation_id.Config) httpware.Middleware
• func Metrics(config *metrics.Config) httpware.Middleware
• func NewResponseWriterInterceptor(writer http.ResponseWriter) *responseWriterInterceptor

Examples

• CorrelationId
• Metrics

Functions

func CorrelationId

func CorrelationId(config *correlation_id.Config) httpware.Middleware

CorrelationId middleware get request id header if provided or generate a request id It will add the request ID to request context and add it to response header to

Example

package main

import (
	"fmt"
	"net/http"

	"github.com/gol4ng/httpware"
	"github.com/gol4ng/httpware/correlation_id"
	"github.com/gol4ng/httpware/middleware"
)

func main() {
	port := ":5001"

	config := correlation_id.NewConfig()
	// you can override default header name
	config.HeaderName = "my-personal-header-name"
	// you can override default id generator
	config.IdGenerator = func(request *http.Request) string {
		return "my-fixed-request-id"
	}

	// we recommend to use MiddlewareStack to simplify managing all wanted middlewares
	// caution middleware order matters
	stack := httpware.MiddlewareStack(
		middleware.CorrelationId(config),
	)

	srv := http.NewServeMux()
	go func() {
		if err := http.ListenAndServe(port, stack.DecorateHandler(srv)); err != nil {
			panic(err)
		}
	}()

	resp, err := http.Get("http://localhost" + port)
	fmt.Printf("%s: %v %v\n", config.HeaderName, resp.Header.Get(config.HeaderName), err)

}

Output:

my-personal-header-name: my-fixed-request-id <nil>

func Metrics

func Metrics(config *metrics.Config) httpware.Middleware

Example

package main

import (
	"net/http"

	"github.com/prometheus/client_golang/prometheus/promhttp"

	"github.com/gol4ng/httpware"
	"github.com/gol4ng/httpware/metrics"

	prom "github.com/gol4ng/httpware/metrics/prometheus"
	"github.com/gol4ng/httpware/middleware"
)

func main() {
	port := ":5002"

	recorder := prom.NewRecorder(prom.Config{}).RegisterOn(nil)

	metricsConfig := metrics.NewConfig(recorder)
	// you can override default identifier provider
	metricsConfig.IdentifierProvider = func(req *http.Request) string {
		return req.URL.Host + " -> " + req.URL.Path
	}

	// we recommend to use MiddlewareStack to simplify managing all wanted middleware
	// caution middleware order matter
	stack := httpware.MiddlewareStack(
		middleware.Metrics(metricsConfig),
	)

	srv := http.NewServeMux()
	srv.Handle("/metrics", promhttp.Handler())

	go func() {
		if err := http.ListenAndServe(port, stack.DecorateHandler(srv)); err != nil {
			panic(err)
		}
	}()

}

func NewResponseWriterInterceptor

func NewResponseWriterInterceptor(writer http.ResponseWriter) *responseWriterInterceptor