Add support for MLflow 2.12 authentication in `mlflow-export-import`

[hunhoon21]

Is your feature request related to a problem? Please describe. With the release of MLflow 2.12, authentication features have been introduced. However, the mlflow-export-import currently does not support these new authentication features. This lack of support limits the use of the tool in secure environments where authentication is required.

Describe the solution you'd like I would like the mlflow-export-import to support the new authentication features introduced in MLflow 2.12. This would involve adding functionality to handle authentication tokens and any necessary configurations to work with authenticated MLflow servers.

Describe alternatives you've considered Currently, the alternative is to manually handle authentication when using the mlflow-export-import tool, which is cumbersome and not user-friendly.

Additional context Supporting MLflow 2.12 authentication features will make the mlflow-export-import more versatile and usable in secure MLflow environments. This enhancement is essential for users who need to manage and transfer MLflow artifacts securely.

[MeraX]

I very much support this request. In particular, I would also welcome if mlflow-export-import would also consider the ~/.mlflow/credentials file.

However I noticed, that import-experiment with mlflow==2.19.0 indeed uses the MLFLOW_TRACKING_USERNAME and MLFLOW_TRACKING_USERNAME environment variables. Furthermore, it is also possible to include username and password in the tracking URI like export MLFLOW_TRACKING_URI=https://$USER:[email protected]:5000. For me, just the credentials file does not work.