build: run graalvm integration tests on emulator (#3198)

* build: run graalvm integration tests on emulator

* fix build

* build: add same TODO as in the JDBC driver

---------

Co-authored-by: Knut Olav Løite <[email protected]>

Author: rahul2393

.kokoro/build.sh

@@ -48,6 +48,16 @@ if [[ ! -z "${GOOGLE_APPLICATION_CREDENTIALS}" && "${GOOGLE_APPLICATION_CREDENTI
     export GOOGLE_APPLICATION_CREDENTIALS=$(realpath ${KOKORO_GFILE_DIR}/${GOOGLE_APPLICATION_CREDENTIALS})
 fi
 
+# Start the Spanner emulator if the environment variable for it has been set.
+# TODO: Change if statement once the env var can be set in the config.
+#if [[ ! -z "${SPANNER_EMULATOR_HOST}" ]]; then
+if [[ "$JOB_TYPE" == "graalvm" ]] || [[ "$JOB_TYPE" == "graalvm17" ]]; then
+  echo "Starting emulator"
+  export SPANNER_EMULATOR_HOST=localhost:9010
+  docker pull gcr.io/cloud-spanner-emulator/emulator
+  docker run -d --rm --name spanner-emulator -p 9010:9010 -p 9020:9020 gcr.io/cloud-spanner-emulator/emulator
+fi
+
 # Kokoro integration test uses both JDK 11 and JDK 8. We ensure the generated class files
 # are compatible with Java 8 when running tests.
 if [ -n "${JAVA8_HOME}" ]; then
@@ -233,6 +243,11 @@ clirr)
     ;;
 esac
 
+if [[ ! -z "${SPANNER_EMULATOR_HOST}" ]]; then
+  echo "Stopping emulator"
+  docker container stop spanner-emulator
+fi
+
 if [ "${REPORT_COVERAGE}" == "true" ]
 then
   bash ${KOKORO_GFILE_DIR}/codecov.sh

google-cloud-spanner/src/test/java/com/google/cloud/spanner/IntegrationTestEnv.java

@@ -87,6 +87,10 @@ protected void initializeConfig()
       throw new NullPointerException("Property " + TEST_ENV_CONFIG_CLASS_NAME + " needs to be set");
     }
     Class<? extends TestEnvConfig> configClass;
+    if (EmulatorSpannerHelper.isUsingEmulator()) {
+      // Make sure that we use an owned instance on the emulator.
+      System.setProperty(TEST_INSTANCE_PROPERTY, "");
+    }
     configClass = (Class<? extends TestEnvConfig>) Class.forName(CONFIG_CLASS);
     config = configClass.newInstance();
   }