added docker compose

Dockerfile

@@ -0,0 +1,16 @@
+FROM golang:alpine AS build
+
+WORKDIR /build
+
+COPY go.mod .
+COPY go.sum .
+COPY *.go ./
+
+RUN go build -o cool-dns .
+
+FROM alpine:latest
+WORKDIR /app
+
+COPY --from=build /build/cool-dns .
+
+ENTRYPOINT ["/app/cool-dns"]

docker-compose.yml

@@ -0,0 +1,11 @@
+version: "3"
+services:
+  cool-dns:
+    build: .
+    ports:
+      - "53:53"
+      - "53:53/udp"
+      - "853:853"
+      - "80:80"
+    volumes:
+      - ./docker:/etc/cool-dns/