# Stage 1: Deterministic Build Environment
FROM rust:1.80-alpine AS builder

RUN apk add --no-cache musl-dev

WORKDIR /usr/src/marlborg-monitor

COPY Cargo.toml Cargo.lock ./
RUN mkdir src && echo "fn main() {}" > src/main.rs && \
    cargo build --release --target=x86_64-unknown-linux-musl && \
    rm -rf src

COPY src ./src
RUN RUSTFLAGS='-C target-feature=+crt-static -C strip=symbols' \
    cargo build --release --target=x86_64-unknown-linux-musl

# Stage 2: Minimal Execution Environment (Zero-OS footprint)
FROM scratch

COPY --from=builder /usr/src/marlborg-monitor/target/x86_64-unknown-linux-musl/release/strain_monitor /strain_monitor

USER 10000:10000

ENTRYPOINT ["/strain_monitor"]