# Make sure RUST_VERSION matches the Rust version
ARG RUST_VERSION=1.92
ARG APP_NAME=docker-rust-hello

################################################################################
# Create a stage for building the application.
################################################################################

FROM dhi.io/rust:${RUST_VERSION}-alpine3.22-dev AS build
ARG APP_NAME
WORKDIR /app

# Install host build dependencies.
RUN apk add --no-cache clang lld musl-dev git

# Build the application.
RUN --mount=type=bind,source=src,target=src \
    --mount=type=bind,source=Cargo.toml,target=Cargo.toml \
    --mount=type=bind,source=Cargo.lock,target=Cargo.lock \
    --mount=type=cache,target=/app/target/ \
    --mount=type=cache,target=/usr/local/cargo/git/db \
    --mount=type=cache,target=/usr/local/cargo/registry/ \
    cargo build --locked --release && \
    cp ./target/release/$APP_NAME /bin/server

################################################################################
# Create a new stage for running the application that contains the minimal
# We use dhi.io/static for the final stage because it’s a minimal Docker Hardened Image runtime (basically “just # enough OS to run the binary”), which helps keep the image small and with a lower attack surface compared to a # # full Alpine/Debian runtime.
################################################################################

FROM dhi.io/static:20250419 AS final

# Create a non-privileged user that the app will run under.
ARG UID=10001
RUN adduser \
    --disabled-password \
    --gecos "" \
    --home "/nonexistent" \
    --shell "/sbin/nologin" \
    --no-create-home \
    --uid "${UID}" \
    appuser
USER appuser

# Copy the executable from the "build" stage.
COPY --from=build /bin/server /bin/

# Configure rocket to listen on all interfaces.
ENV ROCKET_ADDRESS=0.0.0.0

# Expose the port that the application listens on.
EXPOSE 8000

# What the container should run when it is started.
CMD ["/bin/server"]