Hasan Savran takes us through role-based access control in Cosmos DB:
Role-based access control (RBAC) is available for Azure CosmosDB. By using RBAC, you can manage who has access to CosmosDB resources. You need to have a profile in Azure Active Directory to assign RBAC roles to users, groups or other targets. There are 4 built-in roles you can use. Microsoft announced the CosmosDB Operator
Click through for that list.