fix uv venv fail without direct internet access

providers/standard/src/airflow/providers/standard/utils/python_virtualenv.py

@@ -200,9 +200,10 @@ def prepare_virtualenv(
 
     if _use_uv():
         venv_cmd = _generate_uv_cmd(venv_directory, python_bin, system_site_packages)
+        _execute_in_subprocess(venv_cmd, env={**os.environ, **_index_urls_to_uv_env_vars(index_urls)})
     else:
         venv_cmd = _generate_venv_cmd(venv_directory, python_bin, system_site_packages)
-    _execute_in_subprocess(venv_cmd)
+        _execute_in_subprocess(venv_cmd)
 
     pip_cmd = None
     if requirements is not None and len(requirements) != 0:

providers/standard/tests/unit/standard/operators/test_python.py

@@ -1420,9 +1420,18 @@ def f(a):
 
     @mock.patch(
         "airflow.providers.standard.utils.python_virtualenv._execute_in_subprocess",
-        wraps=_execute_in_subprocess,
     )
-    def test_with_index_urls(self, wrapped_execute_in_subprocess):
+    def test_with_index_urls(self, mock_execute_in_subprocess):
+        def safe_execute_in_subprocess(cmd, **kwargs):
+            """Wrapper that removes unreachable URLs from env before executing."""
+            env = kwargs.get("env", {}).copy()
+            # Remove fake URLs to allow venv creation to succeed
+            env.pop("UV_DEFAULT_INDEX", None)
+            env.pop("UV_INDEX", None)
+            return _execute_in_subprocess(cmd, **{**kwargs, "env": env if env else None})
+
+        mock_execute_in_subprocess.side_effect = safe_execute_in_subprocess
+
         def f(a):
             import sys
             from pathlib import Path
@@ -1443,15 +1452,30 @@ def f(a):
             op_args=[4],
         )
 
-        # first call creates venv, second call installs packages
-        package_install_call_args = wrapped_execute_in_subprocess.call_args[1]
-        assert package_install_call_args["env"]["UV_DEFAULT_INDEX"] == "https://first.package.index"
+        # Verify that env was passed with the correct index URLs to pip install
+        # The first call is venv creation (with cleaned env), second call is pip install (with full env)
+        assert len(mock_execute_in_subprocess.call_args_list) >= 2
+        package_install_call_args = mock_execute_in_subprocess.call_args_list[1]
+        assert package_install_call_args[1]["env"]["UV_DEFAULT_INDEX"] == "https://first.package.index"
         assert (
-            package_install_call_args["env"]["UV_INDEX"]
+            package_install_call_args[1]["env"]["UV_INDEX"]
             == "http://second.package.index http://third.package.index"
         )
 
-    def test_with_index_url_from_connection(self, monkeypatch):
+    @mock.patch(
+        "airflow.providers.standard.utils.python_virtualenv._execute_in_subprocess",
+    )
+    def test_with_index_url_from_connection(self, mock_execute_in_subprocess, monkeypatch):
+        def safe_execute_in_subprocess(cmd, **kwargs):
+            """Wrapper that removes unreachable URLs from env before executing."""
+            env = kwargs.get("env", {}).copy()
+            # Remove fake URLs to allow venv creation to succeed
+            env.pop("UV_DEFAULT_INDEX", None)
+            env.pop("UV_INDEX", None)
+            return _execute_in_subprocess(cmd, **{**kwargs, "env": env if env else None})
+
+        mock_execute_in_subprocess.side_effect = safe_execute_in_subprocess
+
         class MockConnection(Connection):
             """Mock for the Connection class."""
 

providers/standard/tests/unit/standard/utils/test_python_virtualenv.py

@@ -94,7 +94,8 @@ def test_should_create_virtualenv_uv(self, mock_execute_in_subprocess):
         )
         assert python_bin == "/VENV/bin/python"
         mock_execute_in_subprocess.assert_called_once_with(
-            ["uv", "venv", "--allow-existing", "--seed", "--python", "pythonVER", "/VENV"]
+            ["uv", "venv", "--allow-existing", "--seed", "--python", "pythonVER", "/VENV"],
+            env=mock.ANY,
         )
 
     @mock.patch("airflow.providers.standard.utils.python_virtualenv._execute_in_subprocess")
@@ -125,7 +126,8 @@ def test_should_create_virtualenv_with_system_packages_uv(self, mock_execute_in_
                 "pythonVER",
                 "--system-site-packages",
                 "/VENV",
-            ]
+            ],
+            env=mock.ANY,
         )
 
     @mock.patch("airflow.providers.standard.utils.python_virtualenv._execute_in_subprocess")
@@ -205,6 +207,48 @@ def test_should_create_virtualenv_with_extra_packages_uv(self, mock_execute_in_s
             env=mock.ANY,
         )
 
+    @mock.patch("airflow.providers.standard.utils.python_virtualenv._generate_pip_conf")
+    @mock.patch("airflow.providers.standard.utils.python_virtualenv._execute_in_subprocess")
+    @conf_vars({("standard", "venv_install_method"): "uv"})
+    def test_venv_creation_with_index_urls(
+        self, mock_execute_in_subprocess, mock_generate_pip_conf, tmp_path: Path
+    ):
+        """
+        Test that uv venv creation passes UV_DEFAULT_INDEX env var.
+
+        When package-index connections are available, UV_DEFAULT_INDEX and UV_INDEX
+        environment variables are passed to uv venv command to ensure packages can be
+        downloaded from the specified index during venv creation (e.g., when installing
+        seed packages like pip, setuptools, wheel).
+        """
+        venv_dir = str(tmp_path / "venv")
+        python_bin = prepare_virtualenv(
+            venv_directory=venv_dir,
+            python_bin="pythonVER",
+            system_site_packages=False,
+            requirements=["somepackage"],
+            index_urls=["https://private.package.index"],
+        )
+        assert python_bin == f"{venv_dir}/bin/python"
+
+        # First call: venv creation should have UV_DEFAULT_INDEX in env
+        venv_call_args = mock_execute_in_subprocess.call_args_list[0]
+        venv_cmd = venv_call_args[0][0]
+        venv_kwargs = venv_call_args[1]
+
+        assert venv_cmd == ["uv", "venv", "--allow-existing", "--seed", "--python", "pythonVER", venv_dir]
+        assert "env" in venv_kwargs
+        assert venv_kwargs["env"]["UV_DEFAULT_INDEX"] == "https://private.package.index"
+
+        # Second call: pip install should also have UV_DEFAULT_INDEX
+        pip_call_args = mock_execute_in_subprocess.call_args_list[1]
+        pip_cmd = pip_call_args[0][0]
+        pip_kwargs = pip_call_args[1]
+
+        assert pip_cmd == ["uv", "pip", "install", "--python", f"{venv_dir}/bin/python", "somepackage"]
+        assert "env" in pip_kwargs
+        assert pip_kwargs["env"]["UV_DEFAULT_INDEX"] == "https://private.package.index"
+
     @pytest.mark.parametrize(
         ("decorators", "expected_decorators"),
         [