httputils.go

package main

import (
	"bufio"
	"errors"
	"github.com/rs/zerolog/log"
	"net"
	"net/http"
)

type statusIntercepter struct {
	next       http.ResponseWriter
	statuscode *int
}

func (h statusIntercepter) Header() http.Header {
	return h.next.Header()
}

func (h statusIntercepter) Write(data []byte) (int, error) {
	return h.next.Write(data)
}

func (h statusIntercepter) WriteHeader(statusCode int) {
	h.next.WriteHeader(statusCode)
	if h.statuscode != nil {
		*h.statuscode = statusCode
	}
}

func (h statusIntercepter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
	next, ok := h.next.(http.Hijacker)
	if !ok {
		return nil, nil, errors.New("hijack not supported")
	}

	return next.Hijack()
}

func createStatusIntercepter(next http.ResponseWriter, i *int) statusIntercepter {
	return statusIntercepter{
		next:       next,
		statuscode: i,
	}
}

type LoggingHandler struct {
	next http.Handler
}

func (h LoggingHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	statusCode := 200
	intercepter := createStatusIntercepter(w, &statusCode)
	h.next.ServeHTTP(intercepter, r)

	log.Debug().Str("Remote", r.RemoteAddr).
		Str("Method", r.Method).
		Str("UserAgent", r.UserAgent()).
		Str("Path", r.URL.Path).
		Int("StatusCode", statusCode).
		Msg("Serving page")
}

const (
	CachePolicyNever  = iota
	CachePolicyAlways = iota
)

type CacheHeaderInserter struct {
	next   http.Handler
	policy int
}

func (h CacheHeaderInserter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	switch h.policy {
	case CachePolicyAlways:
		w.Header().Set("Cache-Control", "public, max-age=15552000")
	case CachePolicyNever:
		w.Header().Set("Cache-Control", "no-cache, max-age=0")
	}

	h.next.ServeHTTP(w, r)
}

func CreateCacheHeaderInserter(next http.Handler, policy int) CacheHeaderInserter {
	return CacheHeaderInserter{
		next:   next,
		policy: policy,
	}
}