middleware

Documentation

Index

• Constants
• func AttachLogger(log zerolog.Logger) func(http.Handler) http.Handler
• func CORS(appEnv string, origins ...string) func(http.Handler) http.Handler
• func DefaultMiddleware(router *chi.Mux, log zerolog.Logger, conf MiddlwareConfig)
• func Recoverer(env string) func(http.Handler) http.Handler
• func ResponseTime(next http.Handler) http.Handler
• func Timeout(timeout time.Duration) func(next http.Handler) http.Handler
• func TrackRequest() func(http.Handler) http.Handler
• type MiddlwareConfig
• type TimedResponseWriter

Constants

const ResponseTimeHeader = "X-Response-Time"

Functions

func AttachLogger

func AttachLogger(log zerolog.Logger) func(http.Handler) http.Handler

AttachLogger attaches a new zerolog.Logger to each new HTTP request. Stolen from https://github.com/rs/zerolog/blob/master/hlog/hlog.go

func CORS

func CORS(appEnv string, origins ...string) func(http.Handler) http.Handler

CORS sets CORS for the handler based on the app environment, making the rules lax in dev environment.

func DefaultMiddleware

func DefaultMiddleware(router *chi.Mux, log zerolog.Logger, conf MiddlwareConfig)

Sets a reasonable set of middleware in the right order taking into consideration those that defer computation(especially)

Middleware set up include: - Automatic request IDs - Response time middleware - Real IP middleware - Middleware for hanging slashes - Compressing response body - CORS handling for dev and production - Request Logging - Response time header - Panic Recovery(with special support for APIError) - Timeouts on request conctext

func Recoverer

func Recoverer(env string) func(http.Handler) http.Handler

Recoverer creates a middleware that handles panics from chi controllers. It handles printing(optionally stack trace in dev env) and responding to the client for all errors except JSendErrors. Note that all errors(bar JSendError) respond with a 500

func ResponseTime

func ResponseTime(next http.Handler) http.Handler

ResponseTime adds a "X-Response-Time" header once the handler writes the header of the response.

func Timeout

func Timeout(timeout time.Duration) func(next http.Handler) http.Handler

Timeout is a middleware that cancels ctx after a given timeout and return a 504 Gateway Timeout error to the client. P.S this was copied directly from go-chi, only removed writing to the response.

It's required that you select the ctx.Done() channel to check for the signal if the context has reached its deadline and return, otherwise the timeout signal will be just ignored.

ie. a route/handler may look like:

 r.Get("/long", func(w http.ResponseWriter, r *http.Request) {
	 ctx := r.Context()
	 processTime := time.Duration(rand.Intn(4)+1) * time.Second

	 select {
	 case <-ctx.Done():
	 	return

	 case <-time.After(processTime):
	 	 // The above channel simulates some hard work.
	 }

	 w.Write([]byte("done"))
 })

func TrackRequest

func TrackRequest() func(http.Handler) http.Handler

TrackRequest updates a future log entry with the request parameters such as request ID and headers.

Types

type MiddlwareConfig

type MiddlwareConfig struct {
	Environment      string        // Application environment(dev, test e.t.c.)
	Timeout          time.Duration // Duration of request before it returns a 504. Defaults to 1 minute
	CompressionLevel int           // Level of compression for responses. Defaults to 5
	CORSOrigins      []string      // list of allowed origins
}

type TimedResponseWriter

type TimedResponseWriter interface {
	http.ResponseWriter
	Code() int
	Duration() time.Duration
}

TimedResponseWriter is a wrapper around the http.ResponseWriter allowing users to track the processing time of an handler.