Dockerfile

# --- Build stage ---
FROM rust:1.88-slim-bookworm AS builder

WORKDIR /build

RUN apt-get update && apt-get install -y --no-install-recommends \
    pkg-config libssl-dev && rm -rf /var/lib/apt/lists/*

# Cache deps (only re-downloaded if Cargo.toml/lock change)
COPY Cargo.toml Cargo.lock ./
RUN mkdir src && echo "fn main() {}" > src/main.rs && touch src/lib.rs
RUN cargo build --release
RUN rm -rf src

# Build actual source
COPY src ./src
RUN touch src/main.rs src/lib.rs
RUN cargo build --release

# --- Runtime stage ---
FROM debian:bookworm-slim

RUN apt-get update && apt-get install -y --no-install-recommends \
    ca-certificates && rm -rf /var/lib/apt/lists/*

COPY --from=builder /build/target/release/trading-engine /trading-engine

ENV RUST_LOG=info
EXPOSE 8080
CMD ["/trading-engine"]