Incremental docker build for validator image

This diff changes build time from 40 to few minutes for incremental change, which is incredibly valuable during triage

docker/validator/build.sh

@@ -8,4 +8,21 @@ if [ "$https_proxy" ]; then
     PROXY=" --build-arg https_proxy=$https_proxy --build-arg http_proxy=$http_proxy"
 fi
 
+rm -f libra-node-from-docker
+
+docker build -f $DIR/validator_builder.Dockerfile $DIR/../.. --tag libra-node-builder $PROXY
+TARGET=$DIR/../../target/libra-node-builder/
+mkdir -p $TARGET
+if docker ps -f name=libra-node-builder-container -f ancestor=libra-node-builder | grep libra-node-builder-container ; then
+  echo "Builder container is running with latest builder image"
+else
+  echo "Builder image has changed, re-creating builder container"
+  docker rm -f libra-node-builder-container || echo "Build container did not exist"
+  docker run --name libra-node-builder-container -d -i -t -v $DIR/../..:/libra libra-node-builder bash
+fi
+
+docker exec -i -t libra-node-builder-container bash -c 'source /root/.cargo/env; cargo build -p libra-node --target-dir /target && /bin/cp /target/debug/libra-node target/libra-node-builder/'
+
+ln target/libra-node-builder/libra-node libra-node-from-docker
 docker build -f $DIR/validator.Dockerfile $DIR/../.. --tag libra_e2e --build-arg GIT_REV="$(git rev-parse HEAD)" --build-arg GIT_UPSTREAM="$(git merge-base HEAD origin/master)" --build-arg BUILD_DATE="$(date -u +'%Y-%m-%dT%H:%M:%SZ')" $PROXY
+rm -f libra-node-from-docker

docker/validator/validator.Dockerfile

@@ -1,28 +1,8 @@
-FROM debian:stretch as builder
-
-# To use http/https proxy while building, use:
-# docker build --build-arg https_proxy=http://fwdproxy:8080 --build-arg http_proxy=http://fwdproxy:8080
-
-RUN echo "deb http://deb.debian.org/debian stretch-backports main" > /etc/apt/sources.list.d/backports.list \
-    && apt-get update && apt-get install -y protobuf-compiler/stretch-backports cmake curl clang \
-    && apt-get clean && rm -r /var/lib/apt/lists/*
-
-RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain none
-ENV PATH "$PATH:/root/.cargo/bin"
-
-WORKDIR /libra
-COPY rust-toolchain /libra/rust-toolchain
-RUN rustup install $(cat rust-toolchain)
-
-COPY . /libra
-RUN cargo build --release -p libra-node -p client -p benchmark
-
-### Production Image ###
 FROM debian:stretch
 
 RUN mkdir -p /opt/libra/bin /opt/libra/etc
 COPY docker/install-tools.sh /root
-COPY --from=builder /libra/target/release/libra-node /opt/libra/bin
+COPY libra-node-from-docker /opt/libra/bin/libra-node
 
 # Admission control
 EXPOSE 8000

docker/validator/validator_builder.Dockerfile

@@ -0,0 +1,15 @@
+FROM debian:stretch
+
+# To use http/https proxy while building, use:
+# docker build --build-arg https_proxy=http://fwdproxy:8080 --build-arg http_proxy=http://fwdproxy:8080
+
+RUN echo "deb http://deb.debian.org/debian stretch-backports main" > /etc/apt/sources.list.d/backports.list \
+    && apt-get update && apt-get install -y protobuf-compiler/stretch-backports cmake curl clang
+#     && apt-get clean && rm -r /var/lib/apt/lists/*
+
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain none
+ENV PATH "$PATH:/root/.cargo/bin"
+
+WORKDIR /libra
+COPY rust-toolchain /libra/rust-toolchain
+RUN rustup install $(cat rust-toolchain)