Kubernetes provider for external identities #658
Description
Is your feature request related to a problem?
Currently, for a user choosing to sync secrets in Phase to a Kubernetes Cluster via the Phase Kubernetes Operator manual provisioning of a Phase Service Toke is need inside of the cluster as a managed secret. While this works well for smaller clusters, this creates unneeded operational overhead for larger cluster or for users will multiple parallel clusters.
Describe the solution you'd like
Add an external identities API that will allow a client to use a Kubernetes JWT token that Phase can validate and return a token if a trust relationship to a Kubernetes Service Account exists.
Additional context
We will also have to update the Kubernetes Secrets Operator to support this new external identity.