tools/internal_ci/helper_scripts/prepare_build_linux_rc

#!/bin/bash
# Copyright 2017 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Source this rc script to prepare the environment for linux builds

tools/internal_ci/helper_scripts/gen_report_index.sh

# Need to increase open files limit for c tests
ulimit -n 32768

# Move docker's storage location to scratch disk so we don't run out of space.
echo 'DOCKER_OPTS="${DOCKER_OPTS} --graph=/tmpfs/docker"' | sudo tee --append /etc/default/docker
sudo service docker restart

# Populate xdg-cache-home to workaround https://github.com/grpc/grpc/issues/11968
sudo mkdir -p /tmp/xdg-cache-home
PYTHONWARNINGS=ignore XDG_CACHE_HOME=/tmp/xdg-cache-home sudo -E pip install setuptools wheel
PYTHONWARNINGS=ignore XDG_CACHE_HOME=/tmp/xdg-cache-home sudo -E pip install coverage==4.4 pylint==1.6.5

# Download Docker images from DockerHub
export DOCKERHUB_ORGANIZATION=grpctesting

# If this is a PR using RUN_TESTS_FLAGS var, then add flags to filter tests
if [ -n "$KOKORO_GITHUB_PULL_REQUEST_NUMBER" ] && [ -n "$RUN_TESTS_FLAGS" ]; then
  sudo apt-get install -y jq
  ghprbTargetBranch=$(curl -s https://api.github.com/repos/grpc/grpc/pulls/$KOKORO_GITHUB_PULL_REQUEST_NUMBER | jq -r .base.ref)
  export RUN_TESTS_FLAGS="$RUN_TESTS_FLAGS --filter_pr_tests --base_branch origin/$ghprbTargetBranch"	
fi

git submodule update --init