HTTP proxy written in Go to replace Tinyproxy (#269)

internal/httpproxy/handler.go

@@ -0,0 +1,62 @@
+package httpproxy
+
+import (
+	"context"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/qdm12/golibs/logging"
+)
+
+func newHandler(ctx context.Context, wg *sync.WaitGroup,
+	client *http.Client, logger logging.Logger,
+	stealth, verbose bool, username, password string) http.Handler {
+	const relayTimeout = 10 * time.Second
+	return &handler{
+		ctx:          ctx,
+		wg:           wg,
+		client:       client,
+		logger:       logger,
+		relayTimeout: relayTimeout,
+		verbose:      verbose,
+		stealth:      stealth,
+		username:     username,
+		password:     password,
+	}
+}
+
+type handler struct {
+	ctx                context.Context
+	wg                 *sync.WaitGroup
+	client             *http.Client
+	logger             logging.Logger
+	relayTimeout       time.Duration
+	verbose, stealth   bool
+	username, password string
+}
+
+func (h *handler) ServeHTTP(responseWriter http.ResponseWriter, request *http.Request) {
+	if len(h.username) > 0 && !isAuthorized(responseWriter, request, h.username, h.password) {
+		h.logger.Info("%s unauthorized", request.RemoteAddr)
+		return
+	}
+	switch request.Method {
+	case http.MethodConnect:
+		h.handleHTTPS(responseWriter, request)
+	default:
+		h.handleHTTP(responseWriter, request)
+	}
+}
+
+// http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
+var hopHeaders = [...]string{ //nolint:gochecknoglobals
+	"Connection",
+	"Keep-Alive",
+	"Proxy-Authenticate",
+	"Proxy-Authorization",
+	"Te", // canonicalized version of "TE"
+	"Trailers",
+	"Transfer-Encoding",
+	"Upgrade",
+}