buildscripts: xds-k8s use shared driver install library

Author: sergiitk

buildscripts/kokoro/xds-k8s.sh

@@ -3,6 +3,8 @@ set -eo pipefail
 
 # Constants
 readonly GITHUB_REPOSITORY_NAME="grpc-java"
+readonly INSTALL_DRIVER_LIB_DOWNLOAD="${INSTALL_DRIVER_LIB_DOWNLOAD:-1}"
+readonly INSTALL_DRIVER_LIB_DOWNLOAD_URL="https://raw.githubusercontent.com/grpc/grpc/master/tools/internal_ci/linux/grpc_xds_k8s_install_test_driver.sh"
 # GKE Cluster
 readonly GKE_CLUSTER_NAME="interop-test-psm-sec-testing-api"
 readonly GKE_CLUSTER_ZONE="us-west1-b"
@@ -147,8 +149,20 @@ run_test() {
 main() {
   local script_dir
   script_dir="$(dirname "$0")"
-  # shellcheck source=buildscripts/kokoro/xds-k8s-install-test-driver.sh
-  source "${script_dir}/xds-k8s-install-test-driver.sh"
+
+  local install_driver_lib_path
+  if [[ -n "${INSTALL_DRIVER_LIB_DOWNLOAD}" && -n "${INSTALL_DRIVER_LIB_DOWNLOAD_URL}" ]]; then
+    # Download shared install driver library.
+    echo "Downloading shared install driver common library: ${INSTALL_DRIVER_LIB_DOWNLOAD_URL}."
+    install_driver_lib_path="$(mktemp -d)/grpc_xds_k8s_install_test_driver.sh"
+    wget --https-only "${INSTALL_DRIVER_LIB_DOWNLOAD_URL}" -O "$(mktemp -d)/grpc_xds_k8s_install_test_driver.sh"
+  else
+    # Use local driver library (use for development).
+    install_driver_lib_path="${script_dir}/grpc_xds_k8s_install_test_driver.sh"
+    echo "Using local shared install driver common library: ${install_driver_lib_path}"
+  fi
+
+  source "${install_driver_lib_path}"
   set -x
   if [[ -n "${KOKORO_ARTIFACTS_DIR}" ]]; then
     kokoro_setup_test_driver "${GITHUB_REPOSITORY_NAME}"