restructure folders

docker/.dockerignore

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+Dockerfile

docker/Cargo.toml

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+[package]
+name = "docker_sample"
+version = "1.0.0"
+edition = "2021"
+
+[dependencies]
+actix-web = "4.0.0-beta.21"
+env_logger = "0.9"
+log = "0.4"

docker/Dockerfile

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+# NB: This is not a production-grade Dockerfile.
+
+#################
+## build stage ##
+#################
+FROM rust:1-slim-bullseye AS builder
+WORKDIR /code
+
+# Download crates-io index and fetch dependency code.
+# This step avoids needing to spend time on every build downloading the index
+# which can take a long time within the docker context. Docker will cache it.
+RUN USER=root cargo init
+COPY Cargo.toml Cargo.toml
+RUN cargo fetch
+
+# copy app files
+COPY src src
+
+# compile app
+RUN cargo build --release
+
+###############
+## run stage ##
+###############
+FROM debian:bullseye-slim
+WORKDIR /app
+
+# copy server binary from build stage
+COPY --from=builder /code/target/release/docker_sample docker_sample
+
+# set user to non-root unless root is required for your app
+USER 1001
+
+# indicate what port the server is running on
+EXPOSE 8080
+
+# run server
+CMD [ "/app/docker_sample" ]

docker/README.MD

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+# Docker sample
+
+## Build image
+
+```shell
+docker build -t docker_sample .
+```
+
+## Run built image
+
+```shell
+docker run -d -p 8080:8080 docker_sample
+# and the server should start instantly
+curl http://localhost:8080
+```
+
+## Running unit tests
+
+```shell
+docker build -t docker_sample:test .
+docker run --rm docker_sample:test
+```

docker/src/main.rs

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+use actix_web::{get, middleware::Logger, App, HttpResponse, HttpServer, Responder};
+
+#[get("/")]
+async fn index() -> impl Responder {
+    HttpResponse::Ok().body("Hello world!")
+}
+
+#[get("/again")]
+async fn again() -> impl Responder {
+    HttpResponse::Ok().body("Hello world again!")
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
+
+    log::info!("Starting HTTP server: go to http://localhost:8080");
+
+    HttpServer::new(|| {
+        App::new()
+            .wrap(Logger::default())
+            .service(index)
+            .service(again)
+    })
+    .bind(("0.0.0.0", 8080))?
+    .run()
+    .await
+}