gradio_client only forwards cookies when using auth

[danbgoldman]

Describe the bug

The python gradio_client library does not cache any server cookies unless the Client constructor is called with password authentication via auth argument. (You can see this by inspecting the code: The Client.cookies member is only set in one place, on this line, inside the _login method.)

However, cookies are not only used for authentication. They are also needed in other scenarios - such as, properly routing requests when using multiple replicas of a service in Kubernetes. (The documentation mentions using sessionAffinity, but this doesn't work with ingress, as explained here.)

Have you searched existing issues? 🔎

• I have searched and found no existing issues

Reproduction

This bug is reproducible with any demo running in multiple replicas in Kubernetes, when called using the client API. But it's a bit tricky to provide a minimal example here, because it would include docker containers, k8s yamls and all kinds of other things that have nothing to do with gradio.

Screenshot

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Logs

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System Info

I've reproduced this bug mostly with gradio 4.43.0 but it also seems to still be present in the latest version (5.8.0) as seen on GitHub.

Gradio Environment Information:
------------------------------
Operating System: Linux
gradio version: 4.44.1
gradio_client version: 1.3.0

------------------------------------------------
gradio dependencies in your environment:

aiofiles: 23.2.1
anyio: 4.6.2.post1
fastapi: 0.115.4
ffmpy: 0.4.0
gradio-client==1.3.0 is not installed.
httpx: 0.27.2
huggingface-hub: 0.26.2
importlib-resources: 6.4.5
jinja2: 3.1.2
markupsafe: 2.1.1
matplotlib: 3.4.2
numpy: 1.21.1
orjson: 3.10.11
packaging: 21.3
pandas: 1.3.5
pillow: 10.2.0
pydantic: 2.9.2
pydub: 0.25.1
python-multipart: 0.0.17
pyyaml: 6.0
ruff: 0.7.2
semantic-version: 2.10.0
tomlkit==0.12.0 is not installed.
typer: 0.12.5
typing-extensions: 4.12.2
urllib3: 2.2.3
uvicorn: 0.32.0
authlib; extra == 'oauth' is not installed.
itsdangerous; extra == 'oauth' is not installed.


gradio_client dependencies in your environment:

fsspec: 2024.10.0
httpx: 0.27.2
huggingface-hub: 0.26.2
packaging: 21.3
typing-extensions: 4.12.2
websockets: 12.0

Severity

I can work around it

[abidlabs]

Thanks @danbgoldman would you like to open a PR for a fix for this? Happy to review

[danbgoldman]

I'm not sure the best way to fix this.

1. The easy solution is just to make an arbitrary GET / request to initialize the cookies. But that introduces unnecessary network overhead.
2. The network-friendly solution would be to lazily initialize the cookies on the first (or every) returned response. But that would require refactoring all the httpx calls.

Is there a URL to query that will just return a short response with headers? I see heartbeat, but I don't want a streaming response, just an "alive" message.

[abidlabs]

Hi @danbgoldman could we do this as part of _get_config()? This gets called once when the Client is initiated. We could append any cookies that are returned to self.cookies

[danbgoldman]

Yes I think so. (I am waiting on my employer's approval to make open-source contributions. This may not happen until after the holidays.)