go-deferred
defer handler creation like what?!?!?
package deferred asynchronously creates an HTTP handler by calling a function that may fail and retries in case of failure.
Example
// only return a http.Handler in some cases
func createLuckyHandler() (http.Handler, error) {
num := rand.Intn(10)
if num != 7 {
return nil, fmt.Errorf("%d is not the lucky number", num)
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Lucky you!"))
})
}
timeout, cancel := context.WithTimeout(context.Background(), time.Hour)
defer cancel()
// NewHandler returns instantly
h := deferred.NewHandler(
// in case the context is cancelled the handler will stop buffering and fail permanently
timeout,
// in case no error is returned, the handler will stop buffering and use the returned handler
createLuckyHandler,
// optional settings
deferred.WithNotify(err error) { // subscribe to errors
fmt.Println("got error: ", err, ", trying again")
},
deferred.WithExponentialBackoff(time.Second), // retry after a second, then use exponential backoff
deferred.WithTimeoutAfter(time.Second * 30), // buffered requests will timeout after 15 seconds
deferred.WithFailedHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
http.Error(w, "sorry, but i stopped trying", http.StatusServiceUnavailable)
})),
)
http.Handle("/", h)License
MIT © Frederik Ring