chore: adding back Dockerfile

Dockerfile

@@ -0,0 +1,40 @@
+# FROM rust:1.32 as build
+FROM alpine:3.9 AS build
+
+RUN apk add --no-cache gcc musl-dev
+RUN apk add --no-cache rust cargo
+
+# RUN rustup target add x86_64-unknown-linux-musl
+
+# Create new empty shell project
+RUN USER=root cargo new --bin app
+WORKDIR /app
+
+# Copy over Cargo.toml
+COPY ./Cargo.toml ./Cargo.toml
+
+# Change target env
+ENV RUSTFLAGS="-C target-cpu=native"
+# ENV RUSTFLAGS="-C target-cpu=x86_64_alpine-linux-musl"
+# Run build step to cache dependencies
+RUN cargo build --release
+RUN rm src/*.rs
+
+# Copy over src files
+COPY ./src/main.rs ./src/main.rs
+
+# Build for release
+RUN rm ./target/release/deps/backend_auth*
+RUN cargo build --release
+
+# Copy over .env
+COPY ./.env ./.env
+
+FROM alpine:3.9
+
+RUN apk add --no-cache gcc
+
+COPY --from=build /app/target/release .
+COPY --from=build /app/.env .env
+
+ENTRYPOINT ["./backend-auth"]