SQL session store

[martinpovolny]

The SQL session store has become unusable because there are fixed dependencies on the Memcache.

The websocket worker and the API use TokenStore and TokenManager for their token management and that is hardcoded to use the memcache:

https://github.com/ManageIQ/manageiq/blob/master/lib/token_store.rb#L4

This means that the SQL session store cannot be used for HA or load balancing purposes and the only option left is to use a shared memcache server.

I'd swear I have read some docs that tell to use the SQL session store for HA setup of ManageIQ or CloudForms but cannot find it.

Ping @gtanzillo, @dclarizio, @isimluk. Ideas, directions any inputs welcome.

My current plan is to make sure that the shared memcached approach works. And document it.

[gtanzillo]

Looked at this with @imtayadeway and we realized that now authentication through the classic UI exclusively uses the Rest API therefore bypassing the Rails session_store setting. We'll need to update the API to honor the session_store to enable using SQL as the session store.