Creating a virtual environment via uv venv fail without direct internet access

[alex-brunshtein]

Apache Airflow Provider(s)

standard

Versions of Apache Airflow Providers

apache-airflow-providers-standard:1.9.1

Apache Airflow version

3.1.3

Operating System

Debian GNU/Linux 12 (bookworm)

Deployment

Official Apache Airflow Helm Chart

Deployment details

k8s

What happened

Creating a virtual environment via uv venv in the PythonVirtualenvOperator fails without direct internet access. Access to https://pypi.org/simple/pip/ provided through Artifactory in transparent proxy mode.
A corresponding package-index connection "remote-pypi" has been configured.
When using uv, this connection is only applied during package installation, but not during virtual environment creation:

    python_virtualenv_operator = PythonVirtualenvOperator(
        task_id="python_virtualenv_operator",
        python_callable=python_virtualenv_code,
        requirements=["certifi"],
        index_urls_from_connection_ids=["remote-pypi"],
    )

[2025-12-03 15:29:25] INFO - DAG bundles loaded: dags-folder, example_dags source=airflow.dag_processing.bundles.manager.DagBundlesManager loc=manager.py:179
[2025-12-03 15:29:25] INFO - Filling up the DagBag from /opt/airflow/dags/repo/dags/repo1/airflow-3/python_operators.py source=airflow.models.dagbag.DagBag loc=dagbag.py:593
[2025-12-03 15:29:25] INFO - Task instance is in running state source=task.stdout
[2025-12-03 15:29:25] INFO -  Previous state of the Task instance: TaskInstanceState.QUEUED source=task.stdout
[2025-12-03 15:29:25] INFO - Current task name:python_virtualenv_operator source=task.stdout
[2025-12-03 15:29:25] INFO - Dag name:af3_python_operators source=task.stdout
[2025-12-03 15:29:25] WARNING - Connection schemes (type: package_index) shall not contain '_' according to RFC3986. source=airflow.sdk.definitions.connection loc=connection.py:130
[2025-12-03 15:29:25] INFO - Executing cmd: uv venv --allow-existing --seed --python python --system-site-packages /tmp/venv2c51r6_g source=airflow.utils.process_utils loc=process_utils.py:188
[2025-12-03 15:29:25] INFO - Output: source=airflow.utils.process_utils loc=process_utils.py:192
[2025-12-03 15:29:26] INFO - Using CPython 3.12.7 interpreter at: /usr/local/bin/python source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:29:26] INFO - Creating virtual environment with seed packages at: /tmp/venv2c51r6_g source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO - uv::venv::seed source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -  source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -   × Failed to install seed packages source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -   ├─▶ No solution found when resolving: `pip` source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -   ├─▶ Failed to fetch: `https://pypi.org/simple/pip/` source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -   ├─▶ Request failed after 3 retries source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -   ├─▶ error sending request for url (https://pypi.org/simple/pip/) source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] INFO -   ╰─▶ operation timed out source=airflow.utils.process_utils loc=process_utils.py:196
[2025-12-03 15:31:31] ERROR - Task failed with exception source=task loc=task_runner.py:1002
CalledProcessError: Command '['uv', 'venv', '--allow-existing', '--seed', '--python', 'python', '--system-site-packages', '/tmp/venv2c51r6_g']' returned non-zero exit status 1.
File "/home/airflow/.local/lib/python3.12/site-packages/airflow/sdk/execution_time/task_runner.py", line 928 in run

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/sdk/execution_time/task_runner.py", line 1315 in _execute_task

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/sdk/bases/operator.py", line 416 in wrapper

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/providers/standard/operators/python.py", line 488 in execute

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/sdk/bases/operator.py", line 416 in wrapper

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/providers/standard/operators/python.py", line 213 in execute

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/providers/standard/operators/python.py", line 892 in execute_callable

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/providers/standard/operators/python.py", line 770 in _prepare_venv

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/providers/standard/utils/python_virtualenv.py", line 172 in prepare_virtualenv

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/utils/process_utils.py", line 177 in execute_in_subprocess

File "/home/airflow/.local/lib/python3.12/site-packages/airflow/utils/process_utils.py", line 200 in execute_in_subprocess_with_kwargs

[2025-12-03 15:31:31] INFO - Task instance in failure state source=task.stdout

What you think should happen instead

Creating venv via uv not use UV_INDEX_URL and use --seed flag:
cmd = ["uv", "venv", "--allow-existing", "--seed", "--python", python_bin]

How to reproduce

Use uv for package installation
Block direct internet access.
Use only package-index connections to install common packages

Anything else

It's worked if adding the environment variable UV_INDEX_URL for venv creation (similar to how it's handled during package installation).
Needs change python_virtualenv.py
For example, change
_execute_in_subprocess(venv_cmd)
to
_execute_in_subprocess(venv_cmd, env={**os.environ, **_index_urls_to_uv_env_vars(index_urls)})
as for pip_cmd

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template! If you are willing to raise PR to address this issue please do so, no need to wait for approval.

[henry3260]

Can I work on this?

[alex-brunshtein]

Yes

[Arunodoy18]

Hi, i think i can solve this issue , I would love to contribute on this issue , .take-issue.
Thank you.

[alex-brunshtein]

uv venv works great!
Many thanks!