public static DatastoreOptions.Builder getOptionsfromEnv()
throws GeneralSecurityException, IOException {
DatastoreOptions.Builder options = new DatastoreOptions.Builder();
options.dataset(System.getenv("DATASTORE_DATASET"));
options.host(System.getenv("DATASTORE_HOST"));
Credential credential = getComputeEngineCredential();
if (credential != null) {
logger.info("Using Compute Engine credential.");
} else if (System.getenv("DATASTORE_SERVICE_ACCOUNT") != null &&
System.getenv("DATASTORE_PRIVATE_KEY_FILE") != null) {
credential = getServiceAccountCredential(System.getenv("DATASTORE_SERVICE_ACCOUNT"),