update Dockerfile to use caches

Author: kevaundray

Dockerfile

@@ -1,18 +1,25 @@
 FROM rust:1.88.0-bullseye AS builder
 RUN apt-get update && apt-get -y upgrade && apt-get install -y cmake libclang-dev
-COPY . lighthouse
+WORKDIR /lighthouse
+
 ARG FEATURES
 ARG PROFILE=release
 ARG CARGO_USE_GIT_CLI=true
 ENV FEATURES=$FEATURES
 ENV PROFILE=$PROFILE
 ENV CARGO_NET_GIT_FETCH_WITH_CLI=$CARGO_USE_GIT_CLI
-RUN cd lighthouse && make
+ENV CARGO_INCREMENTAL=1
+
+COPY . .
+# Persist the registry and target file across builds. See: https://docs.docker.com/build/cache/optimize/#use-cache-mounts
+RUN --mount=type=cache,target=/usr/local/cargo/registry \
+    --mount=type=cache,target=/lighthouse/target \
+    make
 
 FROM ubuntu:22.04
 RUN apt-get update && apt-get -y upgrade && apt-get install -y --no-install-recommends \
   libssl-dev \
   ca-certificates \
   && apt-get clean \
   && rm -rf /var/lib/apt/lists/*
-COPY --from=builder /usr/local/cargo/bin/lighthouse /usr/local/bin/lighthouse
+COPY --from=builder /usr/local/cargo/bin/lighthouse /usr/local/bin/lighthouse