Added allrpc Dockerfile (#444)

cmd/signal/allrpc/Dockerfile

@@ -0,0 +1,24 @@
+FROM golang:1.14.14-stretch
+
+ENV GO111MODULE=on
+
+WORKDIR $GOPATH/src/github.com/pion/ion-sfu
+
+COPY go.mod go.sum ./
+RUN cd $GOPATH/src/github.com/pion/ion-sfu && go mod download
+
+COPY pkg/ $GOPATH/src/github.com/pion/ion-sfu/pkg
+COPY cmd/ $GOPATH/src/github.com/pion/ion-sfu/cmd
+
+WORKDIR $GOPATH/src/github.com/pion/ion-sfu/cmd/signal/allrpc
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o /sfu .
+
+FROM alpine:3.12.3
+
+RUN apk --no-cache add ca-certificates
+COPY --from=0 /sfu /usr/local/bin/sfu
+
+COPY config.toml /configs/sfu.toml
+
+ENTRYPOINT ["/usr/local/bin/sfu"]
+CMD ["-c", "/configs/sfu.toml"]

cmd/signal/allrpc/main.go

@@ -80,6 +80,22 @@ func parse() bool {
 	help := flag.Bool("h", false, "help info")
 	flag.Parse()
 
+	if gaddr == "" {
+		gaddr = getEnv("gaddr")
+	}
+
+	if jaddr == "" {
+		jaddr = getEnv("jaddr")
+	}
+
+	if paddr == "" {
+		paddr = getEnv("paddr")
+	}
+
+	if maddr == "" {
+		maddr = getEnv("maddr")
+	}
+
 	// at least set one
 	if gaddr == "" && jaddr == "" {
 		return false
@@ -95,6 +111,14 @@ func parse() bool {
 	return true
 }
 
+func getEnv(key string) string {
+    if value, exists := os.LookupEnv(key); exists {
+		return value
+    }
+
+    return ""
+}
+
 func main() {
 	if !parse() {
 		showHelp()