Tenant System

Introduction

A tenant is the main unit of security on the platform. The closest analogy would be Linux kernel namespaces.

Tenants can be created recursively and are subject to the following rules:

Tenant naming

Tenant names must be alphanumeric. Using dashes (-) in tenant names is not allowed, unlike with other services. This limitation exists to keep consistent naming in tenants, nested tenants, and services deployed in them.

For example:

• The root tenant is named root, but internally it’s referenced as tenant-root.
• A nested tenant could be named foo, which would result in tenant-foo in service names and URLs.
• However, a tenant can not be named foo-bar, because parsing names such as tenant-foo-bar would be ambiguous.

Nested tenants

Tenants can be nested. A tenant administrator can create nested tenants using the “Tenant” application from the catalogue. Higher-level tenants can view and manage the applications of all their children tenants.

Unique domains

Each tenant has its own domain. By default, (unless otherwise specified), it inherits the domain of its parent with a prefix of its name. For example, if the parent had the domain example.org, then tenant-foo would get the domain foo.example.org by default.

Kubernetes clusters created in this tenant namespace would get domains like: kubernetes-cluster.foo.example.org

Lower-level tenants can access the cluster services of their parent (in case they do not run their own)

By default there is tenant-root with a set of services like etcd, ingress, monitoring. You can create create another tenant namespace tenant-foo inside of tenant-root and even more tenant-bar inside of tenant-foo.

Let’s see what will happen when you run Kubernetes and Postgres under tenant-bar namespace.

Since tenant-bar does not have its own cluster services like ingress, and monitoring, the applications will use the cluster services of the parent tenant.
This in turn means:

• The Kubernetes cluster data will be stored in etcd for tenant-bar.
• All metrics will be collected in the monitoring from tenant-foo.
• Access to the cluster will be through the common ingress of tenant-root.

See the reference for the application implementing tenant management: tenant