init

forward_handler.go

@@ -0,0 +1,61 @@
+package mps
+
+import (
+	"io"
+	"net/http"
+)
+
+type ForwardHandler struct {
+	Ctx *Context
+}
+
+func NewForwardHandler() *ForwardHandler {
+	return &ForwardHandler{
+		Ctx: NewContext(),
+	}
+}
+
+func NewForwardHandlerWithContext(ctx *Context) *ForwardHandler {
+	return &ForwardHandler{
+		Ctx: ctx,
+	}
+}
+
+func (forward *ForwardHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	// Copying a Context preserves the Transport, Middleware
+	ctx := forward.Ctx.Copy()
+	ctx.Request = req
+
+	// In some cases it is not always necessary to remove the Proxy Header.
+	// For example, cascade proxy
+	if !forward.Ctx.KeepHeader {
+		removeProxyHeaders(req)
+	}
+
+	resp, err := ctx.Next(req)
+	if err != nil {
+		http.Error(rw, err.Error(), 500)
+		return
+	}
+
+	origBody := resp.Body
+	defer origBody.Close()
+
+	// http.ResponseWriter will take care of filling the correct response length
+	// Setting it now, might impose wrong value, contradicting the actual new
+	// body the user returned.
+	// We keep the original body to remove the header only if things changed.
+	// This will prevent problems with HEAD requests where there's no body, yet,
+	// the Content-Length header should be set.
+	if origBody != resp.Body {
+		resp.Header.Del("Content-Length")
+	}
+	copyHeaders(rw.Header(), resp.Header, forward.Ctx.KeepDestinationHeaders)
+	rw.WriteHeader(resp.StatusCode)
+	io.Copy(rw, resp.Body)
+	resp.Body.Close()
+}
+
+func (forward *ForwardHandler) Transport() *http.Transport {
+	return forward.Ctx.Transport
+}