Enable config file support

README.md

@@ -35,9 +35,14 @@ $ "$GOPATH/bin/morty" --help
 Morty can be configured using the following environment variables:
 - `MORTY_ADDRESS`: Listen address (default to `127.0.0.1:3000`)
 - `MORTY_KEY`: HMAC url validation key (base64 encoded) to prevent direct URL opening. Leave blank to disable validation. Use `openssl rand -base64 33` to generate.
-- `REPLACE_SITES`: Enable/disable the WIP feature of redirecting sites to privacy respecting alternatives
 - `DEBUG`: Enable/disable proxy and redirection logs (default to `true`). Set to `false` to disable.
 
+### Site replacement
+
+Morty can be told to replace sites with alternative ones, in the default `sites.json` we redirect YouTube to Invidious and Twitter to Nitter.
+
+To enable this feature run morty with the `-replace` flag.
+
 ### Docker
 
 ```

morty.go

@@ -6,10 +6,12 @@ import (
 	"crypto/sha256"
 	"encoding/base64"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"mime"
 	"net/url"
@@ -38,7 +40,7 @@ const (
 const VERSION = "v0.2.0"
 
 var DEBUG = os.Getenv("DEBUG") != "false"
-var REPLACE_SITES = os.Getenv("REPLACE_SITES") != "false"
+var REPLACE_SITES = false
 
 var CLIENT *fasthttp.Client = &fasthttp.Client{
 	MaxResponseBodySize: 10 * 1024 * 1024, // 10M
@@ -98,12 +100,6 @@ var ALLOWED_CONTENTTYPE_PARAMETERS map[string]bool = map[string]bool{
 	"charset": true,
 }
 
-// Replace sites with more trusted/privacy respecting alternatives
-var REPLACEMENT_SITES = map[string]string{
-	"twitter.com": "nitter.net",
-	"youtube.com": "invidio.us",
-}
-
 var UNSAFE_ELEMENTS [][]byte = [][]byte{
 	[]byte("applet"),
 	[]byte("canvas"),
@@ -268,6 +264,8 @@ var MORTY_HTML_PAGE_END string = `
 
 var FAVICON_BYTES []byte
 
+var siteList = make(map[string]string)
+
 func init() {
 	FaviconBase64 := "iVBORw0KGgoAAAANSUhEUgAAABAAAAAQEAYAAABPYyMiAAAABmJLR0T///////8JWPfcAAAACXBIWXMAAABIAAAASABGyWs+AAAAF0lEQVRIx2NgGAWjYBSMglEwCkbBSAcACBAAAeaR9cIAAAAASUVORK5CYII"
 
@@ -889,7 +887,7 @@ func (rc *RequestConfig) ProxifyURI(uri []byte) (string, error) {
 	}
 
 	if REPLACE_SITES {
-		for site, replace := range REPLACEMENT_SITES {
+		for site, replace := range siteList {
 			if u.Host == site {
 				u.Host = replace
 			}
@@ -1006,6 +1004,7 @@ func main() {
 	version := flag.Bool("version", false, "Show version")
 	requestTimeout := flag.Uint("timeout", 2, "Request timeout")
 	socks5 := flag.String("socks5", "", "SOCKS5 proxy")
+	siteReplace := flag.Bool("replace", false, "Enable experimental site redirection")
 	flag.Parse()
 
 	if *version {
@@ -1022,6 +1021,21 @@ func main() {
 		CLIENT.Dial = fasthttpproxy.FasthttpSocksDialer(*socks5)
 	}
 
+	if *siteReplace {
+		log.Println("Enabling site replacement")
+
+		loadedSiteList, err := ioutil.ReadFile("sites.json")
+		if err != nil {
+			log.Printf("Failed to read sites.json: %s\n", err)
+		}
+
+		err = json.Unmarshal(loadedSiteList, &siteList)
+		if err != nil {
+			fmt.Printf("Error: %s\n", err)
+		}
+		REPLACE_SITES = true
+	}
+
 	p := &Proxy{RequestTimeout: time.Duration(*requestTimeout) * time.Second}
 
 	if *key != "" {

sites.json

@@ -0,0 +1,4 @@
+{
+  "youtube.com": "indivio.us",
+  "twitter.com": "nitter.net"
+}