Cleanup Dockerfile

Dockerfile

@@ -13,29 +13,24 @@
 # limitations under the License.
 
 FROM gcr.io/bazel-public/bazel:6.0.0 AS build
-
-USER root
 COPY . .
-RUN ./cloudbuild.sh build //java/com/google/copybara:copybara_deploy.jar
-RUN mkdir -p /tmp/copybara && \
-    cp bazel-bin/java/com/google/copybara/copybara_deploy.jar /tmp/copybara/
+RUN bazel build //java/com/google/copybara:copybara_deploy.jar
 
-USER ubuntu
 FROM golang:latest AS buildtools
 RUN go install github.com/bazelbuild/buildtools/buildozer@latest
 RUN go install github.com/bazelbuild/buildtools/buildifier@latest
 
 FROM openjdk:11-jre-slim
-WORKDIR /usr/src/app
-ENV COPYBARA_CONFIG=copy.bara.sky \
-    COPYBARA_SUBCOMMAND=migrate \
-    COPYBARA_OPTIONS='' \
-    COPYBARA_WORKFLOW=default \
-    COPYBARA_SOURCEREF=''
-COPY --from=build /tmp/copybara/ /opt/copybara/
+RUN apt-get update && apt-get install -y \
+        git \
+    && rm -rf /var/lib/apt/lists/*
+COPY --from=build /home/ubuntu/bazel-bin/java/com/google/copybara/copybara_deploy.jar /opt/copybara/
 COPY --from=buildtools /go/bin/buildozer /go/bin/buildifier /usr/bin/
+ENV COPYBARA_SUBCOMMAND="migrate" \
+    COPYBARA_CONFIG="copy.bara.sky" \
+    COPYBARA_WORKFLOW="default" \
+    COPYBARA_SOURCEREF="" \
+    COPYBARA_OPTIONS=""
 COPY .docker/entrypoint.sh /usr/local/bin/copybara
 RUN chmod +x /usr/local/bin/copybara
-RUN apt-get update && \
-    apt-get install -y git && \
-    apt-get clean
+WORKDIR /usr/src/app