Foreman » Smart Proxy

Foreman smart-proxy uses `redfish_client` gem as backend to implement the Redfish implementation for BMC.

`redfish_client` is a wrapper around the Redfish REST API available on BMC.

This client automatically authenticates the connection using basic auth, then retrieve a Redfish's session which is a token used in Redfish implementation.

Redfish specifications allow single authenticated calls but prefer the session opening before running multiple commands.
Basically, multiple commands should be ran using this scheme:

1. login: ie. retrieve a token (session) using basic auth
2. send many commands using the token in headers
3. logout: ie. request the sessions endpoint to delete the current one

But in Foreman's implementation, we login but never logout.

As side effect, when I go to BMC tab on (old) host UI, many connections to BMC are opened, each one produce a new session and when sessions limit is reached, BMC info can not be retrieved.

To test, I used iDRAC 8 using latest firmware (2.86.86.86) which allow me to debug the session creation by Foreman's Smart Proxy, internally made by `redfish_client`.

PS: I already have some working code and will provide a PR.