make git clone optional

tools/jenkins/docker_run.sh

@@ -33,16 +33,22 @@
 
 set -e
 
-mkdir -p /var/local/git
-git clone --recursive "$EXTERNAL_GIT_ROOT" /var/local/git/grpc
+if [ "$RELATIVE_COPY_PATH" == "" ]
+then
+  mkdir -p /var/local/git
+  git clone --recursive "$EXTERNAL_GIT_ROOT" /var/local/git/grpc
+else
+  mkdir -p "/var/local/git/grpc/$RELATIVE_COPY_PATH"
+  cp -r "$EXTERNAL_GIT_ROOT/$RELATIVE_COPY_PATH/*" "/var/local/git/grpc/$RELATIVE_COPY_PATH"
+fi
 
 if [ -x "$(command -v rvm)" ]
 then
   rvm use ruby-2.1
 fi
 
-cd /var/local/git/grpc
-
 nvm use 4 || true
 
+cd /var/local/git/grpc
+
 $RUN_COMMAND

tools/run_tests/distribtest_targets.py

@@ -43,7 +43,8 @@ def create_docker_jobspec(name, dockerfile_dir, shell_command, environ={},
   for k,v in environ.iteritems():
     docker_args += ['-e', '%s=%s' % (k, v)]
   docker_env = {'DOCKERFILE_DIR': dockerfile_dir,
-                'DOCKER_RUN_SCRIPT': 'tools/jenkins/docker_run.sh'}
+                'DOCKER_RUN_SCRIPT': 'tools/jenkins/docker_run.sh',
+                'RELATIVE_COPY_PATH': 'test/distrib'}
   jobspec = jobset.JobSpec(
           cmdline=['tools/jenkins/build_and_run_docker.sh'] + docker_args,
           environ=docker_env,