From 22a84c82c473c9067c68f0c4f3d6c899308bbc3e Mon Sep 17 00:00:00 2001
From: Eguzki Astiz Lezaun <eastizle@redhat.com>
Date: Tue, 26 Sep 2023 18:08:27 +0200
Subject: [PATCH] image build: layer caching

---
 .github/workflows/build-image.yaml |  1 +
 Dockerfile                         | 22 +++++++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build-image.yaml b/.github/workflows/build-image.yaml
index a725ff74..0ad7dda0 100644
--- a/.github/workflows/build-image.yaml
+++ b/.github/workflows/build-image.yaml
@@ -36,6 +36,7 @@ jobs:
         with:
           image: limitador
           tags: ${{ env.IMG_TAGS }}
+          layers: true
           platforms: linux/amd64,linux/arm64
           dockerfiles: |
             ./Dockerfile
diff --git a/Dockerfile b/Dockerfile
index 8e44b28d..ef058e96 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -22,11 +22,31 @@ RUN PKGS="gcc-c++ gcc-toolset-12-binutils-gold openssl-devel protobuf-c protobuf
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path --profile minimal --default-toolchain ${RUSTC_VERSION} -c rustfmt -y
 
 WORKDIR /usr/src/limitador
-
 ARG GITHUB_SHA
 ENV GITHUB_SHA=${GITHUB_SHA:-unknown}
 ENV RUSTFLAGS="-C target-feature=-crt-static"
 
+COPY ./Cargo.lock ./Cargo.lock
+COPY ./Cargo.toml ./Cargo.toml
+
+COPY limitador/Cargo.toml ./limitador/Cargo.toml
+COPY limitador-server/Cargo.toml ./limitador-server/Cargo.toml
+
+RUN mkdir -p limitador/src limitador-server/src
+
+RUN echo "fn main() {println!(\"if you see this, the build broke\")}" > limitador/src/main.rs \
+ && echo "fn main() {println!(\"if you see this, the build broke\")}" > limitador-server/src/main.rs
+
+RUN source $HOME/.cargo/env \
+    && cargo build --release
+
+# avoid downloading and compiling all the dependencies when there's a change in
+# our code.
+RUN ls target
+RUN ls target/release
+RUN ls target/release/deps
+RUN rm -f target/release/limitador*
+
 COPY . .
 
 RUN source $HOME/.cargo/env \