samples: add code samples for PostgreSql dialect (#836)

* samples: add code samples for PostgreSql dialect

* linting

* fix: remove unnecessary imports

* remove unused import

* fix: change method doc references in parser

* add another command

* test: add samples tests for PG

* fix: linting

* feat: sample tests config changes

* refactor

* refactor

* refactor

* refactor

* add database dialect

* database dialect fixture change

* fix ddl

* yield operation as well

* skip backup tests

* config changes

* fix

* minor lint fix

* some tests were getting skipped. fixing it.

* fix test

* fix test and skip few tests for faster testing

* re-enable tests

Co-authored-by: Astha Mohta <[email protected]>
Co-authored-by: Astha Mohta <[email protected]>

Author: rajatbhatta

samples/samples/conftest.py

@@ -17,6 +17,9 @@
 import uuid
 
 from google.api_core import exceptions
+
+from google.cloud import spanner_admin_database_v1
+from google.cloud.spanner_admin_database_v1.types.common import DatabaseDialect
 from google.cloud.spanner_v1 import backup
 from google.cloud.spanner_v1 import client
 from google.cloud.spanner_v1 import database
@@ -26,17 +29,32 @@
 
 INSTANCE_CREATION_TIMEOUT = 560  # seconds
 
+OPERATION_TIMEOUT_SECONDS = 120  # seconds
+
 retry_429 = retry.RetryErrors(exceptions.ResourceExhausted, delay=15)
 
 
 @pytest.fixture(scope="module")
 def sample_name():
     """Sample testcase modules must define this fixture.
 
-    The name is used to label the instance created by the sample, to
-    aid in debugging leaked instances.
-    """
-    raise NotImplementedError("Define 'sample_name' fixture in sample test driver")
+      The name is used to label the instance created by the sample, to
+      aid in debugging leaked instances.
+      """
+    raise NotImplementedError(
+      "Define 'sample_name' fixture in sample test driver")
+
+
+@pytest.fixture(scope="module")
+def database_dialect():
+    """Database dialect to be used for this sample.
+
+      The dialect is used to initialize the dialect for the database.
+      It can either be GoogleStandardSql or PostgreSql.
+      """
+    # By default, we consider GOOGLE_STANDARD_SQL dialect. Other specific tests
+    # can override this if required.
+    return DatabaseDialect.GOOGLE_STANDARD_SQL
 
 
 @pytest.fixture(scope="session")
@@ -87,7 +105,7 @@ def multi_region_instance_id():
 @pytest.fixture(scope="module")
 def instance_config(spanner_client):
     return "{}/instanceConfigs/{}".format(
-        spanner_client.project_name, "regional-us-central1"
+      spanner_client.project_name, "regional-us-central1"
     )
 
 
@@ -98,20 +116,20 @@ def multi_region_instance_config(spanner_client):
 
 @pytest.fixture(scope="module")
 def sample_instance(
-    spanner_client,
-    cleanup_old_instances,
-    instance_id,
-    instance_config,
-    sample_name,
+  spanner_client,
+  cleanup_old_instances,
+  instance_id,
+  instance_config,
+  sample_name,
 ):
     sample_instance = spanner_client.instance(
-        instance_id,
-        instance_config,
-        labels={
-            "cloud_spanner_samples": "true",
-            "sample_name": sample_name,
-            "created": str(int(time.time())),
-        },
+      instance_id,
+      instance_config,
+      labels={
+        "cloud_spanner_samples": "true",
+        "sample_name": sample_name,
+        "created": str(int(time.time())),
+      },
     )
     op = retry_429(sample_instance.create)()
     op.result(INSTANCE_CREATION_TIMEOUT)  # block until completion
@@ -133,20 +151,20 @@ def sample_instance(
 
 @pytest.fixture(scope="module")
 def multi_region_instance(
-    spanner_client,
-    cleanup_old_instances,
-    multi_region_instance_id,
-    multi_region_instance_config,
-    sample_name,
+  spanner_client,
+  cleanup_old_instances,
+  multi_region_instance_id,
+  multi_region_instance_config,
+  sample_name,
 ):
     multi_region_instance = spanner_client.instance(
-        multi_region_instance_id,
-        multi_region_instance_config,
-        labels={
-            "cloud_spanner_samples": "true",
-            "sample_name": sample_name,
-            "created": str(int(time.time())),
-        },
+      multi_region_instance_id,
+      multi_region_instance_config,
+      labels={
+        "cloud_spanner_samples": "true",
+        "sample_name": sample_name,
+        "created": str(int(time.time())),
+      },
     )
     op = retry_429(multi_region_instance.create)()
     op.result(INSTANCE_CREATION_TIMEOUT)  # block until completion
@@ -170,30 +188,59 @@ def multi_region_instance(
 def database_id():
     """Id for the database used in samples.
 
-    Sample testcase modules can override as needed.
-    """
+      Sample testcase modules can override as needed.
+      """
     return "my-database-id"
 
 
 @pytest.fixture(scope="module")
 def database_ddl():
     """Sequence of DDL statements used to set up the database.
 
-    Sample testcase modules can override as needed.
-    """
+      Sample testcase modules can override as needed.
+      """
     return []
 
 
 @pytest.fixture(scope="module")
-def sample_database(sample_instance, database_id, database_ddl):
+def sample_database(
+  spanner_client,
+  sample_instance,
+  database_id,
+  database_ddl,
+  database_dialect):
+    if database_dialect == DatabaseDialect.POSTGRESQL:
+        sample_database = sample_instance.database(
+          database_id,
+          database_dialect=DatabaseDialect.POSTGRESQL,
+        )
+
+        if not sample_database.exists():
+            operation = sample_database.create()
+            operation.result(OPERATION_TIMEOUT_SECONDS)
+
+        request = spanner_admin_database_v1.UpdateDatabaseDdlRequest(
+          database=sample_database.name,
+          statements=database_ddl,
+        )
+
+        operation =\
+            spanner_client.database_admin_api.update_database_ddl(request)
+        operation.result(OPERATION_TIMEOUT_SECONDS)
+
+        yield sample_database
+
+        sample_database.drop()
+        return
 
     sample_database = sample_instance.database(
-        database_id,
-        ddl_statements=database_ddl,
+      database_id,
+      ddl_statements=database_ddl,
     )
 
     if not sample_database.exists():
-        sample_database.create()
+        operation = sample_database.create()
+        operation.result(OPERATION_TIMEOUT_SECONDS)
 
     yield sample_database
 
@@ -203,8 +250,8 @@ def sample_database(sample_instance, database_id, database_ddl):
 @pytest.fixture(scope="module")
 def kms_key_name(spanner_client):
     return "projects/{}/locations/{}/keyRings/{}/cryptoKeys/{}".format(
-        spanner_client.project,
-        "us-central1",
-        "spanner-test-keyring",
-        "spanner-test-cmek",
+      spanner_client.project,
+      "us-central1",
+      "spanner-test-keyring",
+      "spanner-test-cmek",
     )

samples/samples/noxfile.py

@@ -180,6 +180,7 @@ def blacken(session: nox.sessions.Session) -> None:
 # format = isort + black
 #
 
+
 @nox.session
 def format(session: nox.sessions.Session) -> None:
     """
@@ -207,7 +208,9 @@ def _session_tests(
     session: nox.sessions.Session, post_install: Callable = None
 ) -> None:
     # check for presence of tests
-    test_list = glob.glob("**/*_test.py", recursive=True) + glob.glob("**/test_*.py", recursive=True)
+    test_list = glob.glob("**/*_test.py", recursive=True) + glob.glob(
+        "**/test_*.py", recursive=True
+    )
     test_list.extend(glob.glob("**/tests", recursive=True))
 
     if len(test_list) == 0:
@@ -229,9 +232,7 @@ def _session_tests(
 
     if os.path.exists("requirements-test.txt"):
         if os.path.exists("constraints-test.txt"):
-            session.install(
-                "-r", "requirements-test.txt", "-c", "constraints-test.txt"
-            )
+            session.install("-r", "requirements-test.txt", "-c", "constraints-test.txt")
         else:
             session.install("-r", "requirements-test.txt")
         with open("requirements-test.txt") as rtfile:
@@ -244,9 +245,9 @@ def _session_tests(
         post_install(session)
 
     if "pytest-parallel" in packages:
-        concurrent_args.extend(['--workers', 'auto', '--tests-per-worker', 'auto'])
+        concurrent_args.extend(["--workers", "auto", "--tests-per-worker", "auto"])
     elif "pytest-xdist" in packages:
-        concurrent_args.extend(['-n', 'auto'])
+        concurrent_args.extend(["-n", "auto"])
 
     session.run(
         "pytest",
@@ -276,7 +277,7 @@ def py(session: nox.sessions.Session) -> None:
 
 
 def _get_repo_root() -> Optional[str]:
-    """ Returns the root folder of the project. """
+    """Returns the root folder of the project."""
     # Get root of this repository. Assume we don't have directories nested deeper than 10 items.
     p = Path(os.getcwd())
     for i in range(10):