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<h1>Background</h1>
<br>
In Kimchi, now we have a basic authentication model based on PAM.
In this model, all the authenticated user get all of the privileges
to access the resources in Kimchi. However, it is too simple to
cause some security holes and classifying the user with different
roles is a way to address the holes. Roles with very fine grained
privileges need huge effort and time, so here we are trying to split
the effort with several steps. And we will discuss the first step
of the effort in the below which can be achieved in a certain time
bound and reserve the forward compatibility for future extensions.<br>
<br>
<br>
<h1>First step of the effort</h1>
<br>
In this step, the goal is to authorize the user's action on a
resource by roles. The user action here is applied by the REST API
exposed by Kimchi. Every action on Kimchi resources should be
checked based on the user's role. In this step, we will not try to
have roles in a very fine granularity. Naturally, three permanent
roles will be created by default, the system administrator role, the
infrastructure role and the user role.<br>
<br>
* The system administrator get the privileges to manage the roles
for the other users including assigning a role to a user, removing
the role from a user &etc. A default user "admink" will be
created by default with a system administrator role assigned to it.
And the role of the user "admink" can not be modified. <br>
<br>
* The infrastructure role get the privileges to manage the
physical resources and virtual resources including network's
creation and deletion, create or delete storage storage pools or
storage volumes' creation and deletion, adding a user to the user
list of storage storage pool &etc. <br>
<br>
* The user role get the privileges to apply action on VMs
including VMs' starting and stopping, viewing the VM console by VNC
&etc.<br>
<br>
* Some of the change can be enhanced on the existing REST API
like "DELETE /storagepools/poo1/vo1". But we need create new REST
APIs for actions like adding a role for a user like " PUT
/users/user1 {role: "user role"}"<br>
<br>
* Database is needed to store the user information including
roles and resource user list<br>
<br>
Beside the privileges inherited from the user's role, Kimchi will
check if a user get the permission to access a resource based on a
tuple. The tuple is composed from both the privileges of the user
and the user list of the resource. An example is, if a user try ti
delete a storage volume from the stroage pool, Kimchi will check if
it is assigned a infrastructure role and if it is in the user list
of the storage pool.<br>
<br>
<h1>Next step of the effort</h1>
<br>
* The roles are defined in a very fine granularity containing the
privileges precisely matching what the system administrator
expects. <br>
<br>
* Existing roles can by customized by the system administrator from
a set of previleges. The set of privileges should be pre-defined
and hierarchy. <br>
<br>
* The system administrator can create new roles with customized
privileges
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