main.go

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strconv"
	"time"

	"handler/function"
	// "github.com/alexellis/golang-http-template/template/golang-http/function"
	handler "github.com/openfaas-incubator/go-function-sdk"
)

func makeRequestHandler() func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		var input []byte

		if r.Body != nil {
			defer r.Body.Close()

			bodyBytes, bodyErr := ioutil.ReadAll(r.Body)

			if bodyErr != nil {
				log.Printf("Error reading body from request.")
			}

			input = bodyBytes
		}

		req := handler.Request{
			Body:        input,
			Header:      r.Header,
			Method:      r.Method,
			QueryString: r.URL.RawQuery,
		}

		result, resultErr := function.Handle(req)

		if result.Header != nil {
			for k, v := range result.Header {
				w.Header()[k] = v
			}
		}

		if resultErr != nil {
			log.Print(resultErr)
			w.WriteHeader(http.StatusInternalServerError)
		} else {
			if result.StatusCode == 0 {
				w.WriteHeader(http.StatusOK)
			} else {
				w.WriteHeader(result.StatusCode)
			}
		}

		w.Write(result.Body)
	}
}

func parseIntOrDurationValue(val string, fallback time.Duration) time.Duration {
	if len(val) > 0 {
		parsedVal, parseErr := strconv.Atoi(val)
		if parseErr == nil && parsedVal >= 0 {
			return time.Duration(parsedVal) * time.Second
		}
	}

	duration, durationErr := time.ParseDuration(val)
	if durationErr != nil {
		return fallback
	}
	return duration
}

func main() {
	readTimeout := parseIntOrDurationValue(os.Getenv("read_timeout"), 10*time.Second)
	writeTimeout := parseIntOrDurationValue(os.Getenv("write_timeout"), 10*time.Second)

	s := &http.Server{
		Addr:           fmt.Sprintf(":%d", 8082),
		ReadTimeout:    readTimeout,
		WriteTimeout:   writeTimeout,
		MaxHeaderBytes: 1 << 20, // Max header of 1MB
	}

	http.HandleFunc("/", makeRequestHandler())
	log.Fatal(s.ListenAndServe())
}