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Multi-tenant domain model

In Hyku, each tenant is managed by an Account. Account segments the application data as follows:

• First, a unique identifier for the tenant (a random UUID) is generated
• The Apartment gem is used to segment the application database. In the PostgreSQL database, this segmentation occurs via database schemas. So, each Hyku tenant stores its data in its own database schema. (NOTE: Apartment also calls these segments "tenants". But, in Hyku, a tenant encompasses a bit more, as you will see below.)
  • It is worth noting that most models become scoped to an Apartment tenant (i.e. they apply to a specific tenant's database schema). However, Account is a global model, as it manages the tenant.
• A Solr Collection is created specific to the tenant (named with the tenant UUID). All objects in this tenant will be indexed into that collection.
• A Fedora Container is created specific to the tenant (named with the tenant UUID). All objects in this tenant will be stored in this container.
• A Redis namespace is created specific to the tenant (named with the tenant UUID).
• A Site is created. The Site corresponds to this tenant's Hyku application (and is configured to use the defined database schema, Solr collection, Fedora container, etc). Site is a singleton that we use to effectively namespace, e.g., application_name values.

Other models to be aware of:

• Application users are managed by the User model. Each User has one or more Roles. Users are defined within a tenant scope (using Apartment). So, if a user has a login for multiple Sites, those logins are stored separately (and may have different passwords, etc).
• Some Roles are scoped to Sites; some aren't. There is a many-to-many relationship between Roles and Users. We currently have two Roles defined: Site admins and SuperAdmins. SuperAdmins can create/manage tenants, while a Site admin is only an admin in a specific tenant.
• Abilities use Roles to make authorization decisions on Resources (terminology from the rolify gem).

Using account-switching in development

• Flip the multitenancy.enabled setting in config/settings.yml to true (but don't commit this later)
• To support a multitenant setup locally, you'll need to ensure your localhost can respond to multiple subdomains (as each tenant is a subdomain). There's a few options for doing so:
  • Option 1: Use the lvh.me registered domain (which just points at 127.0.0.1) as your configured multitenancy.admin_host in config/settings.yml. This will mean that your main application will be available at http://lvh.me:3000 and a tenant named "test" would be at http://test.lvh.me:3000
  • Option 2: Set up some localhost IPs (one per tenant) in /etc/hosts (or similar), e.g.:

    127.0.2.1       foo
    127.0.3.1       bar
    

    • On OSX 10.11.6, it was also necessary to disable low level packet filtering to allow connections to the additional local IPs, as documented here:

      sudo pfctl -d

• When starting Hyku, be sure to bind the rails server to 0.0.0.0 so that all of your tenants respond to HTTP requests:

  rails s -b 0.0.0.0
  

• To manage your tenants, you'll want to have at least one SuperAdmin user. So, grant one of your users "superadmin" rights. (Note: The square brackets around the email address are required)

  rake superadmin:grant[[email protected]]
  

• Once your application is started, you can login as a superadmin using the "Administrator Login" option in the footer. Once logged in, you'll be able to create a new repository (tenant) or see currently existing tenants via an "Accounts" menu option in header.