[FEAT] - Cluster supports StructuredAuth for access

[IvoGoman]

Priority

None

User Story

As a Cluster administrator, I would like to be able to choose the Cluster auth method, so that I can decide how greenhouse accesses my cluster.

Description

Currently, Greenhouse manages a ServiceAccount on the remote cluster and automatically rotates the token. In case of prolonged downtime of either Greenhouse central, Remote cluster or longer connectivity issues, this token may expire. Once a token is expired it cannot be remediated by Greenhouse but requires manual intervention.

The Cluster CRD needs a field to specify which authentication method is used.
The controllers need to get the kube client used for reconciliation from the Cluster resource.

Acceptance Criteria

• Cluster CRD allows to specify which auth method to use
• Controllers get KubeClient from Cluster

Reference Issues

No response