Lease count quotas

Vault features an extension to resource quotas that allows operators to enforce limits on how many leases are created. For a given lease count quota, if the number of leases in the cluster hits the configured limit, max_leases, additional lease creations will be forbidden for all clients until a lease has been revoked or has expired.

It is important to note that lease count quotas do not apply to the root tokens. If the number of leases in the cluster hits the configured limit, max_leases, an operator could still create a root token and access the cluster to try to recover.

Additionally, batch token creation is blocked when the lease count quota is exceeded, but batch tokens do not count towards the quota.

All the nodes in the Vault cluster will share the lease quota rules, meaning that the lease counters will be shared, regardless of which node in the Vault cluster receives lease generation requests. Lease quotas can be imposed across Vault's API, or scoped down to API pertaining to specific namespaces or specific mounts.

A quota that is defined in the root namespace with no specified path is inherited by all namespaces. Essentially, it applies to the entire Vault API unless a more specific quota has been defined for a specific API path.

Lease count quotas defined on a namespace take precedence over the global quotas. Lease count quotas defined for a mount will take precedence over global and namespace quotas. Lease count quotas defined for a specific path will take precedence over global, namespace, and mount quotas. Lease count quotas defined with a login role for a specific auth mount will take precedence over every other quota when applying to login requests using that auth method and the specified role.

The limits on quotas can either be increased or decreased. If a lower precedence quota is very restrictive and if it is desired to relax the limits in one namespace, or on a specific mount, it can be done using this precedence model. On the other hand, if a lower precedence quota is very liberal and if it is desired to further restrict usages in a specific namespace or mount, that can be done using the precedence model too.

Vault also allows the inspection into the state of lease count quotas in a Vault cluster through various metrics exposed and through enabling optional audit logging.

Tutorial

Refer to Protecting Vault with Resource Quotas for a step-by-step tutorial.

API

Lease count quotas can be managed over the HTTP API. Please see Lease Count Quotas API for more details.