Add $request_uri support

Author: creekorful

README.md

@@ -10,7 +10,7 @@ Create a `direktion.json` config file where you want, with your redirections:
 {
   "redirects": {
     "example.com/blog": {
-      "location": "https://blog.example.org",
+      "location": "https://blog.example.org/$request_uri",
       "code": 307
     },
     "example.com": {

direktion.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"strings"
 )
 
 // Config is the application configuration
@@ -57,16 +58,22 @@ func main() {
 func redirectHandler(c *Config) func(w http.ResponseWriter, r *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if redirect, exist := c.findRedirect(r.Host, r.URL); exist {
+			// determinate status code to use
 			code := http.StatusTemporaryRedirect
 			if redirect.Code != 0 {
 				code = redirect.Code
 			}
 
+			// determinate remote ip address to display
 			remoteIP := r.RemoteAddr
 			if c.UseXForwarded {
 				remoteIP = getRealIP(r)
 			}
 
+			// extrapolate variables in location
+			redirect.Location = strings.Replace(redirect.Location, "$request_uri",
+				strings.TrimPrefix(r.URL.Path, "/"), 1)
+
 			log.Printf("%s - [%d] Redirecting %s%s -> %s", remoteIP, code, r.Host, r.URL.Path, redirect.Location)
 
 			w.Header().Add("Location", redirect.Location)

direktion_test.go

@@ -48,6 +48,17 @@ func TestRedirection(t *testing.T) {
 				},
 			},
 		},
+		{
+			url:              "https://creekorful.me/2019/01/12/terminews",
+			expectedLocation: "https://blog.creekorful.com/2019/01/12/terminews",
+			expectedCode:     308,
+			redirects: map[string]Redirect{
+				"creekorful.me": {
+					Location: "https://blog.creekorful.com/$request_uri",
+					Code:     308,
+				},
+			},
+		},
 	}
 
 	for _, test := range tests {