refactor: Erase excess code in build scripts (#591)

Author: Ilya Gurov

.kokoro/build.sh

@@ -20,13 +20,8 @@ cd github/python-spanner-django
 # Disable buffering, so that the logs stream through.
 export PYTHONUNBUFFERED=1
 
-# Debug: show build environment
-env | grep KOKORO
-
 # Setup service account credentials.
 export GOOGLE_APPLICATION_CREDENTIALS=${KOKORO_GFILE_DIR}/service-account.json
-
-# Setup project id.
 export PROJECT_ID=$(cat "${KOKORO_GFILE_DIR}/project-id.json")
 export GOOGLE_CLOUD_PROJECT=$(cat "${KOKORO_GFILE_DIR}/project-id.json")
 
@@ -45,18 +40,9 @@ else
     python3.6 -m nox
 fi
 
-# Export essential environment variables for Django tests.
 export RUNNING_SPANNER_BACKEND_TESTS=1
 
-# The emulator is currently unusable for our tests because:
-# a) It doesn't support INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE
-# b) Cannot accept parameters whose types aren't known, so can't be used for
-#    Python and other dynamic languages.
-export USE_SPANNER_EMULATOR=0
-
 pip3 install .
-# Create a unique DJANGO_TESTS_DIR per worker to avoid
-# any clashes with configured tests by other workers.
 export DJANGO_TESTS_DIR="django_tests_dir"
 mkdir -p $DJANGO_TESTS_DIR && git clone --depth 1 --single-branch --branch spanner-2.2.x https://github.com/timgraham/django.git $DJANGO_TESTS_DIR/django
 
@@ -65,7 +51,6 @@ sudo apt-get update
 apt-get install -y libffi-dev libjpeg-dev zlib1g-dev libmemcached-dev
 cd $DJANGO_TESTS_DIR/django && pip3 install -e . && pip3 install -r tests/requirements/py3.txt; cd ../../
 
-# Not using the emulator!
 # Hardcode the max number of workers since Spanner has a very low
 # QPS for administrative RPCs of 5QPS (averaged every 100 seconds)
 if [[ $KOKORO_JOB_NAME == *"continuous"* ]]

.kokoro/ensure_instance_exists.py

@@ -37,11 +37,8 @@ TEST_DBNAME=${SPANNER_TEST_DB:-$(python3 -c 'import os, time; print(chr(ord("a")
 TEST_DBNAME_OTHER="$TEST_DBNAME-ot"
 INSTANCE=${SPANNER_TEST_INSTANCE:-django-tests}
 PROJECT=${PROJECT_ID}
-SPANNER_EMULATOR_HOST=${SPANNER_EMULATOR_HOST}
-GOOGLE_CLOUD_PROJECT=${GOOGLE_CLOUD_PROJECT}
 SETTINGS_FILE="$TEST_DBNAME-settings"
 TESTS_DIR=${DJANGO_TESTS_DIR:-django_tests}
-TEST_APPS=${DJANGO_TEST_APPS}
 
 create_settings() {
     cat << ! > "$SETTINGS_FILE.py"
@@ -69,4 +66,4 @@ PASSWORD_HASHERS = [
 cd $TESTS_DIR/django/tests
 create_settings
 
-python3 runtests.py $TEST_APPS --verbosity=3 --noinput --settings $SETTINGS_FILE
+python3 runtests.py $DJANGO_TEST_APPS --verbosity=3 --noinput --settings $SETTINGS_FILE