feat: check Python and dependency versions in generated GAPICs

gapic/templates/%namespace/%name_%version/%sub/__init__.py.j2

@@ -7,6 +7,92 @@ from {{package_path}} import gapic_version as package_version
 
 __version__ = package_version.__version__
 
+
+import google.api_core as api_core
+
+if hasattr(api_core, "check_python_version") and hasattr(api_core, "check_dependency_versions"):   # pragma: NO COVER
+    {# TODO(api_core): remove `type:ignore` below when minimum version of api_core makes the else clause unnecessary. #}
+    api_core.check_python_version("{{package_path}}") # type: ignore
+    api_core.check_dependency_versions("{{package_path}}") # type: ignore
+else:   # pragma: NO COVER
+{# TODO(api_core): Remove this try-catch when we require api-core at a version that
+   supports the changes in https://github.com/googleapis/python-api-core/pull/832
+
+    In the meantime, please ensure the functionality here mirrors the
+    equivalent functionality in api_core, in those two functions above.
+#}
+    # An older version of api_core is installed which does not define the
+    # functions above. We do equivalent checks manually.
+    try:
+        import warnings
+        import sys
+
+        _py_version_str = sys.version.split()[0]
+        _package_label = "{{package_path}}"
+        if sys.version_info < (3, 9):
+            warnings.warn("You are using a non-supported Python version " +
+                          f"({_py_version_str}).  Google will not post any further " +
+                          f"updates to {_package_label} supporting this Python version. " +
+                          "Please upgrade to the latest Python version, or at " +
+                          f"least to Python 3.9, and then update {_package_label}.",
+                          FutureWarning)
+        if sys.version_info[:2] == (3, 9):
+            warnings.warn(f"You are using a Python version ({_py_version_str}) " +
+                          f"which Google will stop supporting in {_package_label} in " +
+                          "January 2026. Please " +
+                          "upgrade to the latest Python version, or at " +
+                          "least to Python 3.10, before then, and " +
+                          f"then update {_package_label}.",
+                          FutureWarning)
+
+        from packaging.version import parse as parse_version
+
+        if sys.version_info < (3, 8):
+            import pkg_resources
+
+            def _get_version(dependency_name):
+              try:
+                version_string = pkg_resources.get_distribution(dependency_name).version
+                return (parse_version(version_string), version_string)
+              except pkg_resources.DistributionNotFound:
+                return (None, "--")
+        else:
+            from importlib import metadata
+
+            def _get_version(dependency_name):
+                try:
+                    version_string = metadata.version("requests")
+                    parsed_version = parse_version(version_string)
+                    return (parsed_version.release, version_string)
+                except metadata.PackageNotFoundError:
+                    return (None, "--")
+
+        _dependency_package = "google.protobuf"
+        _next_supported_version = "4.25.8"
+        _next_supported_version_tuple = (4, 25, 8)
+        _recommendation = " (we recommend 6.x)"
+        (_version_used, _version_used_string) = _get_version(_dependency_package)
+        if _version_used and _version_used < _next_supported_version_tuple:
+            warnings.warn(f"Package {_package_label} depends on " +
+                          f"{_dependency_package}, currently installed at version " +
+                          f"{_version_used_string}. Future updates to " +
+                          f"{_package_label} will require {_dependency_package} at " +
+                          f"version {_next_supported_version} or higher{_recommendation}." +
+                          " Please ensure " +
+                          "that either (a) your Python environment doesn't pin the " +
+                          f"version of {_dependency_package}, so that updates to " +
+                          f"{_package_label} can require the higher version, or " +
+                          "(b) you manually update your Python environment to use at " +
+                          f"least version {_next_supported_version} of " +
+                          f"{_dependency_package}.",
+                          FutureWarning)
+    except Exception:
+            warnings.warn("Could not determine the version of Python " +
+                          "currently being used. To continue receiving " +
+                          "updates for {_package_label}, ensure you are " +
+                          "using a supported version of Python; see " +
+                          "https://devguide.python.org/versions/")
+
 {#  Import subpackages. -#}
 {% for subpackage, _ in api.subpackages|dictsort %}
 from . import {{ subpackage }}

gapic/templates/setup.py.j2

@@ -39,6 +39,7 @@ dependencies = [
     "google-auth >= 2.14.1, <3.0.0,!=2.24.0,!=2.25.0",
     "grpcio >= 1.33.2, < 2.0.0",
     "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
+    "packaging", # TODO: Remove once we require versions of api core that include this
     "proto-plus >= 1.22.3, <2.0.0",
     "proto-plus >= 1.25.0, <2.0.0; python_version >= '3.13'",
     {# Explicitly exclude protobuf versions mentioned in https://cloud.google.com/support/bulletins#GCP-2022-019 #}

gapic/templates/tests/unit/gapic/%name_%version/%sub/test_%service.py.j2

@@ -1472,6 +1472,7 @@ def test_{{ service.name|snake_case }}_grpc_asyncio_transport_channel():
 
 # Remove this test when deprecated arguments (api_mtls_endpoint, client_cert_source) are
 # removed from grpc/grpc_asyncio transport constructor.
+@pytest.mark.filterwarnings("ignore::FutureWarning")
 @pytest.mark.parametrize("transport_class", [transports.{{ service.grpc_transport_name }}, transports.{{ service.grpc_asyncio_transport_name }}])
 def test_{{ service.name|snake_case }}_transport_channel_mtls_with_client_cert_source(
     transport_class

noxfile.py

@@ -61,6 +61,8 @@ def unit(session):
         "pyfakefs",
         "grpcio-status",
         "proto-plus",
+        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
+        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
     session.install("-e", ".")
     session.run(
@@ -482,6 +484,8 @@ def run_showcase_unit_tests(session, fail_under=100, rest_async_io_enabled=False
         "pytest-xdist",
         "asyncmock; python_version < '3.8'",
         "pytest-asyncio",
+        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
+        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
     # Run the tests.
     # NOTE: async rest is not supported against the minimum supported version of google-api-core.
@@ -596,6 +600,8 @@ def showcase_mypy(
         "types-protobuf",
         "types-requests",
         "types-dataclasses",
+        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
+        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
 
     with showcase_library(session, templates=templates, other_opts=other_opts) as lib:
@@ -726,6 +732,8 @@ def mypy(session):
         "types-PyYAML",
         "types-dataclasses",
         "click==8.1.3",
+        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
+        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
     session.install(".")
     session.run("mypy", "-p", "gapic")

tests/integration/goldens/asset/google/cloud/asset_v1/__init__.py

@@ -18,6 +18,85 @@
 __version__ = package_version.__version__
 
 
+import google.api_core as api_core
+
+if hasattr(api_core, "check_python_version") and hasattr(api_core, "check_dependency_versions"):   # pragma: NO COVER
+    api_core.check_python_version("google.cloud.asset_v1") # type: ignore
+    api_core.check_dependency_versions("google.cloud.asset_v1") # type: ignore
+else:   # pragma: NO COVER
+    # An older version of api_core is installed which does not define the
+    # functions above. We do equivalent checks manually.
+    try:
+        import warnings
+        import sys
+
+        _py_version_str = sys.version.split()[0]
+        _package_label = "google.cloud.asset_v1"
+        if sys.version_info < (3, 9):
+            warnings.warn("You are using a non-supported Python version " +
+                          f"({_py_version_str}).  Google will not post any further " +
+                          f"updates to {_package_label} supporting this Python version. " +
+                          "Please upgrade to the latest Python version, or at " +
+                          f"least to Python 3.9, and then update {_package_label}.",
+                          FutureWarning)
+        if sys.version_info[:2] == (3, 9):
+            warnings.warn(f"You are using a Python version ({_py_version_str}) " +
+                          f"which Google will stop supporting in {_package_label} in " +
+                          "January 2026. Please " +
+                          "upgrade to the latest Python version, or at " +
+                          "least to Python 3.10, before then, and " +
+                          f"then update {_package_label}.",
+                          FutureWarning)
+
+        from packaging.version import parse as parse_version
+
+        if sys.version_info < (3, 8):
+            import pkg_resources
+
+            def _get_version(dependency_name):
+              try:
+                version_string = pkg_resources.get_distribution(dependency_name).version
+                return (parse_version(version_string), version_string)
+              except pkg_resources.DistributionNotFound:
+                return (None, "--")
+        else:
+            from importlib import metadata
+
+            def _get_version(dependency_name):
+                try:
+                    version_string = metadata.version("requests")
+                    parsed_version = parse_version(version_string)
+                    return (parsed_version.release, version_string)
+                except metadata.PackageNotFoundError:
+                    return (None, "--")
+
+        _dependency_package = "google.protobuf"
+        _next_supported_version = "4.25.8"
+        _next_supported_version_tuple = (4, 25, 8)
+        _recommendation = " (we recommend 6.x)"
+        (_version_used, _version_used_string) = _get_version(_dependency_package)
+        if _version_used and _version_used < _next_supported_version_tuple:
+            warnings.warn(f"Package {_package_label} depends on " +
+                          f"{_dependency_package}, currently installed at version " +
+                          f"{_version_used_string}. Future updates to " +
+                          f"{_package_label} will require {_dependency_package} at " +
+                          f"version {_next_supported_version} or higher{_recommendation}." +
+                          " Please ensure " +
+                          "that either (a) your Python environment doesn't pin the " +
+                          f"version of {_dependency_package}, so that updates to " +
+                          f"{_package_label} can require the higher version, or " +
+                          "(b) you manually update your Python environment to use at " +
+                          f"least version {_next_supported_version} of " +
+                          f"{_dependency_package}.",
+                          FutureWarning)
+    except Exception:
+            warnings.warn("Could not determine the version of Python " +
+                          "currently being used. To continue receiving " +
+                          "updates for {_package_label}, ensure you are " +
+                          "using a supported version of Python; see " +
+                          "https://devguide.python.org/versions/")
+
+
 from .services.asset_service import AssetServiceClient
 from .services.asset_service import AssetServiceAsyncClient
 

tests/integration/goldens/asset/setup.py

@@ -45,6 +45,7 @@
     "google-auth >= 2.14.1, <3.0.0,!=2.24.0,!=2.25.0",
     "grpcio >= 1.33.2, < 2.0.0",
     "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
+    "packaging", # TODO: Remove once we require versions of api core that include this
     "proto-plus >= 1.22.3, <2.0.0",
     "proto-plus >= 1.25.0, <2.0.0; python_version >= '3.13'",
     "protobuf>=3.20.2,<7.0.0,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",

tests/integration/goldens/asset/tests/unit/gapic/asset_v1/test_asset_service.py

@@ -17712,6 +17712,7 @@ def test_asset_service_grpc_asyncio_transport_channel():
 
 # Remove this test when deprecated arguments (api_mtls_endpoint, client_cert_source) are
 # removed from grpc/grpc_asyncio transport constructor.
+@pytest.mark.filterwarnings("ignore::FutureWarning")
 @pytest.mark.parametrize("transport_class", [transports.AssetServiceGrpcTransport, transports.AssetServiceGrpcAsyncIOTransport])
 def test_asset_service_transport_channel_mtls_with_client_cert_source(
     transport_class

tests/integration/goldens/credentials/google/iam/credentials_v1/__init__.py

@@ -18,6 +18,85 @@
 __version__ = package_version.__version__
 
 
+import google.api_core as api_core
+
+if hasattr(api_core, "check_python_version") and hasattr(api_core, "check_dependency_versions"):   # pragma: NO COVER
+    api_core.check_python_version("google.iam.credentials_v1") # type: ignore
+    api_core.check_dependency_versions("google.iam.credentials_v1") # type: ignore
+else:   # pragma: NO COVER
+    # An older version of api_core is installed which does not define the
+    # functions above. We do equivalent checks manually.
+    try:
+        import warnings
+        import sys
+
+        _py_version_str = sys.version.split()[0]
+        _package_label = "google.iam.credentials_v1"
+        if sys.version_info < (3, 9):
+            warnings.warn("You are using a non-supported Python version " +
+                          f"({_py_version_str}).  Google will not post any further " +
+                          f"updates to {_package_label} supporting this Python version. " +
+                          "Please upgrade to the latest Python version, or at " +
+                          f"least to Python 3.9, and then update {_package_label}.",
+                          FutureWarning)
+        if sys.version_info[:2] == (3, 9):
+            warnings.warn(f"You are using a Python version ({_py_version_str}) " +
+                          f"which Google will stop supporting in {_package_label} in " +
+                          "January 2026. Please " +
+                          "upgrade to the latest Python version, or at " +
+                          "least to Python 3.10, before then, and " +
+                          f"then update {_package_label}.",
+                          FutureWarning)
+
+        from packaging.version import parse as parse_version
+
+        if sys.version_info < (3, 8):
+            import pkg_resources
+
+            def _get_version(dependency_name):
+              try:
+                version_string = pkg_resources.get_distribution(dependency_name).version
+                return (parse_version(version_string), version_string)
+              except pkg_resources.DistributionNotFound:
+                return (None, "--")
+        else:
+            from importlib import metadata
+
+            def _get_version(dependency_name):
+                try:
+                    version_string = metadata.version("requests")
+                    parsed_version = parse_version(version_string)
+                    return (parsed_version.release, version_string)
+                except metadata.PackageNotFoundError:
+                    return (None, "--")
+
+        _dependency_package = "google.protobuf"
+        _next_supported_version = "4.25.8"
+        _next_supported_version_tuple = (4, 25, 8)
+        _recommendation = " (we recommend 6.x)"
+        (_version_used, _version_used_string) = _get_version(_dependency_package)
+        if _version_used and _version_used < _next_supported_version_tuple:
+            warnings.warn(f"Package {_package_label} depends on " +
+                          f"{_dependency_package}, currently installed at version " +
+                          f"{_version_used_string}. Future updates to " +
+                          f"{_package_label} will require {_dependency_package} at " +
+                          f"version {_next_supported_version} or higher{_recommendation}." +
+                          " Please ensure " +
+                          "that either (a) your Python environment doesn't pin the " +
+                          f"version of {_dependency_package}, so that updates to " +
+                          f"{_package_label} can require the higher version, or " +
+                          "(b) you manually update your Python environment to use at " +
+                          f"least version {_next_supported_version} of " +
+                          f"{_dependency_package}.",
+                          FutureWarning)
+    except Exception:
+            warnings.warn("Could not determine the version of Python " +
+                          "currently being used. To continue receiving " +
+                          "updates for {_package_label}, ensure you are " +
+                          "using a supported version of Python; see " +
+                          "https://devguide.python.org/versions/")
+
+
 from .services.iam_credentials import IAMCredentialsClient
 from .services.iam_credentials import IAMCredentialsAsyncClient
 

tests/integration/goldens/credentials/setup.py

@@ -45,6 +45,7 @@
     "google-auth >= 2.14.1, <3.0.0,!=2.24.0,!=2.25.0",
     "grpcio >= 1.33.2, < 2.0.0",
     "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
+    "packaging", # TODO: Remove once we require versions of api core that include this
     "proto-plus >= 1.22.3, <2.0.0",
     "proto-plus >= 1.25.0, <2.0.0; python_version >= '3.13'",
     "protobuf>=3.20.2,<7.0.0,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",

tests/integration/goldens/credentials/tests/unit/gapic/credentials_v1/test_iam_credentials.py

@@ -3972,6 +3972,7 @@ def test_iam_credentials_grpc_asyncio_transport_channel():
 
 # Remove this test when deprecated arguments (api_mtls_endpoint, client_cert_source) are
 # removed from grpc/grpc_asyncio transport constructor.
+@pytest.mark.filterwarnings("ignore::FutureWarning")
 @pytest.mark.parametrize("transport_class", [transports.IAMCredentialsGrpcTransport, transports.IAMCredentialsGrpcAsyncIOTransport])
 def test_iam_credentials_transport_channel_mtls_with_client_cert_source(
     transport_class