Dockerfile-helper

FROM rust:1.58.1-alpine as builder

RUN apk add libc-dev && apk update

# Attempt to install a nonexistent package. This triggers
# updating the crates.io index separately from building the
# dependencies, so if dependencies change we don't have to
# re-download the whole index.
RUN cargo install _update_crates_io_failure_is_expected_ ; true

WORKDIR /usr/src/ppm-prototype

# First, copy just the Cargo.toml and a dummy main, then build them.
# This primes a layer that contains the built dependencies.
COPY Cargo.lock Cargo.lock
COPY Cargo.toml Cargo.toml
RUN sed -i /build.rs/d Cargo.toml
RUN mkdir -p src
RUN echo "fn main() {println!(\"if you see this, the build broke\")}" > src/main.rs
# This cargo build command must match the one below, or the build cache will not be reused.
RUN cargo build

# Clean up and copy the real source.
# After this we have a layer that should be cacheable so long as the dependencies don't change.
RUN rm -f target/*/deps/ppm_prototype* src/main.rs

COPY . .

ARG BUILD_INFO=unspecified

# This cargo build command must match the one above, or the build cache will not be reused.
RUN cargo build --bin helper

# Build a minimal container from Alpine containing only the stripped binary and
# no intermediate build artifacts
FROM alpine:3.15.0

RUN apk add libgcc && apk update

COPY --from=builder /usr/src/ppm-prototype/target/debug/helper /helper
COPY --from=builder /usr/src/ppm-prototype/sample-config/hpke.json /root/.config/ppm-prototype/hpke.json
COPY --from=builder /usr/src/ppm-prototype/sample-config/parameters.json /root/.config/ppm-prototype/parameters.json

CMD ["/helper"]