This tool extends Cargo to allow you to build only the dependencies in a given rust project. This is useful for docker builds where each build step is cached. The time it takes to build dependencies is often a significant portion of the overall build time. Therefore it is beneficial in docker builds to build dependencies in a separate step earlier than the main build. Since the dependency building step will be cached, dependencies will not need to be rebuilt when the project's own source code changes.
Based on https://github.com/nacardin/cargo-build-deps
cargo install cargo-build-dependencies
cargo build-dependencies
Change Dockerfile from
FROM rust:1.43 as rust-builder
RUN mkdir /tmp/PROJECT_NAME
WORKDIR /tmp/PROJECT_NAME
COPY . .
RUN cargo build --release
to
FROM rust:1.43 as rust-builder
RUN cargo install cargo-build-dependencies
RUN cd /tmp && USER=root cargo new --bin PROJECT_NAME
WORKDIR /tmp/PROJECT_NAME
COPY Cargo.toml Cargo.lock ./
RUN cargo build-dependencies --release
COPY src /tmp/PROJECT_NAME/src
RUN cargo build --release
