grpc_interop_java: Remove unnecessary cruft from container

This reduces the container size from 1.4 GB to 640 MB. 129 MB is
jessie, 489 MB jdk, and 22 MB grpc-java. When we swap from jessie to
stretch, we could swap to openjdk:8-jdk-slim-stretch which would make
the entire image 265 MB.

Python was never needed; it was added by mistake in 0589e533.
Pre-downloading gradle artifacts isn't helpful these days, because we
build on a clean machine. Git isn't needed as cp is sufficient. libapr1
has not been required by tcnative for a long time, and we even use
tcnative-boringssl-static since at least 1.0, which also doesn't need
it. The final cleanup is to remove source and downloaded artifacts when
done compiling.

3 files changed, 17 insertions, 21 deletions

diff --git a/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/Dockerfile.include b/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/Dockerfile.include
index e80b51778c..7307e29f0a 100644
--- a/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/Dockerfile.include
+++ b/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/Dockerfile.include
@@ -15,13 +15,6 @@
 <%include file="../../debian_jessie_header.include"/>
 
 <%include file="java_deps.include"/>
-<%include file="../../python_deps.include"/>
-
-# Trigger download of as many Gradle artifacts as possible.
-RUN git clone --recursive --depth 1 https://github.com/grpc/grpc-java.git && ${'\\'}
-  cd grpc-java && ${'\\'}
-  ./gradlew :grpc-interop-testing:installDist -PskipCodegen=true && ${'\\'}
-  rm -r "$(pwd)"
 
 # Define the default command.
-CMD ["bash"]
\ No newline at end of file
+CMD ["bash"]
diff --git a/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/java_deps.include b/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/java_deps.include
index 40d70e06d1..c05b564239 100644
--- a/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/java_deps.include
+++ b/templates/tools/dockerfile/interoptest/grpc_interop_java_oracle8/java_deps.include
@@ -1,16 +1,11 @@
-# Install JDK 8 and Git
+# Install JDK 8
 #
 RUN echo oracle-java8-installer shared/accepted-oracle-license-v1-1 select true | /usr/bin/debconf-set-selections && ${'\\'}
   echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | tee /etc/apt/sources.list.d/webupd8team-java.list && ${'\\'}
   echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | tee -a /etc/apt/sources.list.d/webupd8team-java.list && ${'\\'}
-  apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
-
-RUN apt-get update && apt-get -y install ${'\\'}
-      git ${'\\'}
-      libapr1 ${'\\'}
-      oracle-java8-installer ${'\\'}
-      && ${'\\'}
-    apt-get clean && rm -r /var/cache/oracle-jdk8-installer/
+  apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886 && ${'\\'}
+  apt-get update && apt-get -y install oracle-java8-installer && ${'\\'}
+  apt-get clean && rm -r /var/cache/oracle-jdk8-installer/
 
 ENV JAVA_HOME /usr/lib/jvm/java-8-oracle
 ENV PATH $PATH:$JAVA_HOME/bin
diff --git a/templates/tools/dockerfile/java_build_interop.sh.include b/templates/tools/dockerfile/java_build_interop.sh.include
index 16d5fb65cf..e30b53e3f2 100755
--- a/templates/tools/dockerfile/java_build_interop.sh.include
+++ b/templates/tools/dockerfile/java_build_interop.sh.include
@@ -16,16 +16,24 @@
 # Builds Java interop server and client in a base image.
 set -e
 
-mkdir -p /var/local/git
-git clone --recursive --depth 1 /var/local/jenkins/grpc-java /var/local/git/grpc-java
+cp -r /var/local/jenkins/grpc-java /tmp/grpc-java
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
 
-cd /var/local/git/grpc-java
-
+pushd /tmp/grpc-java
 ./gradlew :grpc-interop-testing:installDist -PskipCodegen=true
 
+mkdir -p /var/local/git/grpc-java/
+cp -r --parents -t /var/local/git/grpc-java/ ${'\\'}
+    interop-testing/build/install/ ${'\\'}
+    run-test-client.sh ${'\\'}
+    run-test-server.sh
+
+popd
+rm -r /tmp/grpc-java
+rm -r "$HOME/.gradle"
+
 # enable extra java logging
 mkdir -p /var/local/grpc_java_logging
 echo "handlers = java.util.logging.ConsoleHandler