Feat/fileserver (#60)

* cleanup code for URL type

* fix makefile for trace mode

* refactor, merge Entry, RawEntry and Route into one. 

* Implement fileserver.

* refactor: rename HTTPRoute to ReverseProxyRoute to avoid confusion

* refactor: move metrics logger to middleware package

- fix prometheus metrics for load balanced routes
  - route will now fail when health monitor fail to start

* fix extra output of ls-* commands by defer initializaing stuff, speed up start time

* add test for path traversal attack, small fix on FileServer.Start method

* rename rule.on.bypass to pass

* refactor and fixed map-to-map  deserialization

* updated route loading logic

* schemas: add "add_prefix" option to modify_request middleware


* updated route JSONMarshalling

---------

Co-authored-by: yusing <yusing@6uo.me>

internal/net/http/middleware/test_utils.go

@@ -12,6 +12,7 @@ import (
 	E "github.com/yusing/go-proxy/internal/error"
 	"github.com/yusing/go-proxy/internal/net/http/reverseproxy"
 	"github.com/yusing/go-proxy/internal/net/types"
+	. "github.com/yusing/go-proxy/internal/utils/testing"
 )
 
 //go:embed test_data/sample_headers.json
@@ -79,11 +80,11 @@ type TestResult struct {
 
 type testArgs struct {
 	middlewareOpt OptionsRaw
-	upstreamURL   types.URL
+	upstreamURL   *types.URL
 
 	realRoundTrip bool
 
-	reqURL    types.URL
+	reqURL    *types.URL
 	reqMethod string
 	headers   http.Header
 	body      []byte
@@ -94,14 +95,14 @@ type testArgs struct {
 }
 
 func (args *testArgs) setDefaults() {
-	if args.reqURL.Nil() {
-		args.reqURL = E.Must(types.ParseURL("https://example.com"))
+	if args.reqURL == nil {
+		args.reqURL = Must(types.ParseURL("https://example.com"))
 	}
 	if args.reqMethod == "" {
 		args.reqMethod = http.MethodGet
 	}
-	if args.upstreamURL.Nil() {
-		args.upstreamURL = E.Must(types.ParseURL("https://10.0.0.1:8443")) // dummy url, no actual effect
+	if args.upstreamURL == nil {
+		args.upstreamURL = Must(types.ParseURL("https://10.0.0.1:8443")) // dummy url, no actual effect
 	}
 	if args.respHeaders == nil {
 		args.respHeaders = http.Header{}