How to integrate containerized scientific applications with Rucio and IAM services

In https://jira.skatelescope.org/browse/SP-4517  we define a solution to make files stored in the Rucio Storage Element available in the user area, fulfilling the access permissions for this files. With prepareData a user that opens a JupyterHub session in the node X, will find in his/her user area those files that they have accessed previously. Access permissions are implemented thanks to the interaction perepareData - Gatekeeper 

In this feature we will explore how we could apply the technical solution developed in prepareData, to any other application than JupyterHub. This solution can be applied to containerized applications that run in a Kubernetes cluster. CARTA could be an example and in this feature we will focus on it. 

The expected outcome from this feature is that a user could open a CARTA session and see in her/his user area files located in the RSE of the node where the CARTA instance is running.

In addition to this, we also explore how we could authenticate users via IAM to access web analysis services. Again we would use CARTA, given it has a web interface. In this case the user should authenticate via the IAM web interface before being redirected to the CARTA web interface.