Load ICE servers from file. Fixes #3

Dockerfile

@@ -1,14 +1,15 @@
-FROM golang:1.11-rc-alpine as build
+FROM golang:1.12-rc-alpine as build
 
-RUN apk add --no-cache git=2.18.1-r0
+RUN apk add --no-cache git=2.20.1-r0
 
 WORKDIR /src
-COPY go.mod go.sum .env *.go ./
+COPY go.mod go.sum .env *.go iceservers.txt ./
 RUN go get -d -v ./...
 RUN CGO_ENABLED=0 go build -ldflags "-s -w"
 
 FROM scratch
 
+COPY --from=build /src/iceservers.txt /iceservers.txt
 COPY --from=build /src/webrtc /webrtc
 COPY --from=build /src/.env /.env
 

iceservers.txt

@@ -0,0 +1 @@
+stun:stun.l.google.com:19302

main.go

@@ -4,9 +4,11 @@ import (
   "context"
   "encoding/json"
   "io"
+  "io/ioutil"
   "log"
   "net/http"
   "os"
+  "strings"
 
   "github.com/joho/godotenv"
   "github.com/julienschmidt/httprouter"
@@ -40,6 +42,23 @@ func main() {
   mediaEngine.RegisterCodec(webrtc.NewRTPOpusCodec(webrtc.DefaultPayloadTypeOpus, 48000))
   webrtcApi = webrtc.NewAPI(webrtc.WithMediaEngine(mediaEngine))
 
+  // Read ICE servers
+  fileBytes, err := ioutil.ReadFile("iceservers.txt")
+  if err != nil {
+    log.Fatal("error opening ice servers file")
+  }
+  fileString := string(fileBytes)
+  servers := strings.Split(fileString, `\n`)
+
+  peerConnectionConfig = webrtc.Configuration{
+    ICEServers: []webrtc.ICEServer{
+      {
+        URLs: servers,
+      },
+    },
+    SDPSemantics: webrtc.SDPSemanticsUnifiedPlanWithFallback,
+  }
+
   userTracks = make(map[string] map[string] *webrtc.Track)
   conversationUsers = make(map[string] []string)
   userConversation = make(map[string] string)