dockerfile & heroku added

Dockerfile

@@ -0,0 +1,15 @@
+FROM rust:1.50.0 as build
+
+WORKDIR /app
+COPY . .
+RUN cargo build --release
+RUN mkdir -p /build-out
+RUN cp target/release/actix-messaging /build-out/
+
+# Ubuntu 18.04
+FROM ubuntu:18.04 as production
+
+RUN apt-get update && apt-get -y install ca-certificates libssl-dev && rm -rf /var/lib/apt/lists/*
+COPY --from=build /build-out/* /
+
+CMD [ "./actix-messaging" ]

heroku.yml

@@ -0,0 +1,3 @@
+build:
+  docker:
+    app: Dockerfile

src/main.rs

@@ -11,13 +11,17 @@ use routes::connect;
 
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
+
+    let port = std::env::var("PORT").expect("PORT env variable not found");
+    let addr = format!("127.0.0.1:{}", port);
+
     let chat = ChatServer::new().start();
     HttpServer::new(move || {
         App::new()
             .data(AppState { chat: chat.clone() })
             .service(connect)
     })
-    .bind("127.0.0.1:8080")?
+    .bind(&addr)?
     .run()
     .await
 }