fix(cli): default deploy images to Python 3.12

src/google/adk/cli/cli_deploy.py

@@ -266,7 +266,7 @@ def _resolve_python_version_from_agent_config(
 
   Supports three sources, in increasing precedence:
 
-  1. The default, ``3.11``.
+  1. The default, ``3.12``.
   2. Top-level ``python_version`` in ``.agent_engine_config.json`` (popped so
      it is not forwarded to the Agent Engine API, which ignores it when the
      image is built from a Dockerfile).

src/google/adk/cli/cli_tools_click.py

@@ -590,11 +590,11 @@ def deploy_options(command: _F) -> _F:
       click.option(
           "--python_version",
           type=str,
-          default="3.11",
+          default="3.12",
           show_default=True,
           help=(
               "Optional. The Python version used in the container image"
-              " (default: 3.11)."
+              " (default: 3.12)."
           ),
       ),
       click.argument(
@@ -2741,7 +2741,7 @@ def cli_deploy_cloud_run(
     provider_args: tuple[str, ...] = (),
     env: tuple[str, ...] = (),
     extra_packages: tuple[str, ...] = (),
-    python_version: str = "3.11",
+    python_version: str = "3.12",
 ) -> None:
   """Deploys an agent to Cloud Run.
 
@@ -2825,7 +2825,7 @@ def cli_deploy_docker(
     a2a: bool = False,
     provider_args: tuple[str, ...] = (),
     env: tuple[str, ...] = (),
-    python_version: str = "3.11",
+    python_version: str = "3.12",
 ) -> None:
   """Deploys an agent to a local Docker container."""
   _warn_if_with_ui(with_ui)
@@ -3128,7 +3128,7 @@ def cli_migrate_session(
         "Optional. The Python version used in the container image. Overrides"
         " `python_version` in `.agent_engine_config.json` when both are set."
         " (default: `python_version` from `.agent_engine_config.json`, or"
-        " 3.11)"
+        " 3.12)"
     ),
 )
 @click.option(
@@ -3399,11 +3399,11 @@ def cli_deploy_agent_engine(
 @click.option(
     "--python_version",
     type=str,
-    default="3.11",
+    default="3.12",
     show_default=True,
     help=(
         "Optional. The Python version used in the container image"
-        " (default: 3.11)."
+        " (default: 3.12)."
     ),
 )
 # Kept as raw str (not parsed to list) — interpolated directly into Dockerfile CMD.
@@ -3482,7 +3482,7 @@ def cli_deploy_gke(
     trigger_oidc_audience: str | None = None,
     trigger_oidc_service_accounts: str | None = None,
     extra_packages: tuple[str, ...] = (),
-    python_version: str = "3.11",
+    python_version: str = "3.12",
 ) -> None:
   """Deploys an agent to GKE.
 

src/google/adk/cli/deployers/_dockerfile_template.py

@@ -31,7 +31,7 @@
     r'^[A-Za-z0-9_-][A-Za-z0-9_.-]{0,62}$'
 )
 
-_DEFAULT_PYTHON_VERSION: Final[str] = '3.11'
+_DEFAULT_PYTHON_VERSION: Final[str] = '3.12'
 
 _PYTHON_VERSION_PATTERN: Final[re.Pattern[str]] = re.compile(
     r'^3\.(1[1-9]|[2-9][0-9])(\.[0-9]+)?$'
@@ -250,7 +250,7 @@ def _render_dockerfile(
     express_mode_option: `--express_mode` or an empty string.
     extra_packages_copy: Extra `COPY`/`ENV` instructions, or an empty string.
     extra_env_vars: Extra `ENV` lines, or an empty string.
-    python_version: The Python version for the base image (default: '3.11').
+    python_version: The Python version for the base image (default: '3.12').
 
   Returns:
     The Dockerfile contents.

tests/unittests/cli/utils/test_cli_deploy.py

@@ -3152,15 +3152,15 @@ def test_to_agent_engine_renders_python_version_and_pops_config_key(
   assert "python_version" not in captured[0]
 
 
-@pytest.mark.parametrize("cli_python_version", ["3.11", "3.13"])
+@pytest.mark.parametrize("cli_python_version", ["3.12", "3.13"])
 def test_to_agent_engine_cli_python_version_overrides_config_file(
     monkeypatch: pytest.MonkeyPatch,
     agent_dir: Callable[[bool, bool], Path],
     cli_python_version: str,
 ) -> None:
   """An explicit python_version wins over .agent_engine_config.json.
 
-  Covers both the value that equals the built-in default (3.11) and a
+  Covers both the value that equals the built-in default (3.12) and a
   different one, so the override cannot depend on a default sentinel.
   """
   monkeypatch.setattr(shutil, "rmtree", _Recorder())
@@ -3194,7 +3194,7 @@ def test_to_agent_engine_defaults_python_version_without_flag_or_config(
     monkeypatch: pytest.MonkeyPatch,
     agent_dir: Callable[[bool, bool], Path],
 ) -> None:
-  """With neither the flag nor a config key, the image is built on 3.11."""
+  """With neither the flag nor a config key, the image is built on 3.12."""
   monkeypatch.setattr(shutil, "rmtree", _Recorder())
   captured: List[Dict[str, Any]] = []
   recording_agentplatform = _make_recording_agentplatform(captured)
@@ -3215,7 +3215,7 @@ def test_to_agent_engine_defaults_python_version_without_flag_or_config(
   )
 
   dockerfile_content = (tmp_dir / "Dockerfile").read_text()
-  assert "FROM python:3.11-slim" in dockerfile_content
+  assert "FROM python:3.12-slim" in dockerfile_content
 
 
 def test_to_agent_engine_rejects_non_string_python_version_in_config(

tests/unittests/cli/utils/test_cli_deploy_to_cloud_run.py

@@ -195,7 +195,7 @@ def test_to_cloud_run_happy_path(
     assert "--with_ui" not in cmd_argv
   assert "--port=8080" in cmd_argv
   assert cmd_argv[-1] == "/app/agents"
-  assert "FROM python:3.11-slim" in dockerfile_content
+  assert "FROM python:3.12-slim" in dockerfile_content
   assert (
       'RUN adduser --disabled-password --gecos "" myuser' in dockerfile_content
   )