perf: improve Dockerfile caching (#1053)

Author: MegaRedHand

Dockerfile

@@ -33,19 +33,37 @@ RUN apt-get update && apt-get install -y cmake protobuf-compiler
 # Install protobuf for elixir
 RUN mix escript.install --force hex protobuf
 
+# Download openapi spec
+COPY Makefile .oapi_version /consensus/
+RUN make download-beacon-node-oapi
+
 # Install rust
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
 
 ENV PATH="${PATH}:/root/.cargo/bin:/root/.mix/escripts"
 
+# Precompile rust crates. Rustler stores targets under _build
+COPY ./native /consensus/native
+RUN cd /consensus/native/bls_nif && cargo build --release \
+    --target-dir="/consensus/_build/prod/lib/lambda_ethereum_consensus/native/bls_nif"
+RUN cd /consensus/native/kzg_nif && cargo build --release \
+    --target-dir="/consensus/_build/prod/lib/lambda_ethereum_consensus/native/kzg_nif"
+RUN cd /consensus/native/snappy_nif && cargo build --release \
+    --target-dir="/consensus/_build/prod/lib/lambda_ethereum_consensus/native/snappy_nif"
+RUN cd /consensus/native/ssz_nif && cargo build --release \
+    --target-dir="/consensus/_build/prod/lib/lambda_ethereum_consensus/native/ssz_nif"
+
+# Precompile elixir dependencies
+COPY mix.exs mix.lock .fork_version ./
+COPY ./config/config.exs /consensus/config/config.exs
+RUN mix deps.get
+RUN mix deps.compile
+
 COPY . .
 COPY --from=libp2p_builder /libp2p_port/libp2p_port /consensus/priv/native/libp2p_port
 
 RUN protoc --elixir_out=./lib proto/libp2p.proto
 
-RUN make download-beacon-node-oapi
-
-RUN mix deps.get
 RUN mix compile
 
 ENTRYPOINT [ "iex", "-S", "mix", "run", "--"]