LibCloud backend

This is an experimental provisioning backend that eventually intends to support several libcloud drivers. At this time only the OpenStack driver is supported.


  • An account with an OpenStack provider that supports Nova and Cinder

  • A DNS server supporting RFC 2136. We use bind and this ansible role to help configure ours.

  • An nsupdate-web instance configured to update DNS records. We use an ansible role for this as well.

  • Configuration in teuthology.yaml for this backend itself (see Configuration) and nsupdate-web

  • You will also need to choose a maximum number of nodes to be running at once, and create records in your paddles database for each one - making sure to set is_vm to True for each.


An example configuration using OVH as an OpenStack provider:

    ovh:  # This string is the 'machine type' value you will use when locking these nodes
      driver: openstack
      driver_args:  # driver args are passed directly to the libcloud driver
        username: 'my_ovh_username'
        password: 'my_ovh_password'
        ex_force_auth_url: ''
        ex_force_auth_version: '2.0_password'
        ex_tenant_name: 'my_tenant_name'
        ex_force_service_region: 'my_region'

Why nsupdate-web?

While we could have supported directly calling nsupdate, we chose not to. There are a few reasons for this:

  • To avoid piling on yet another feature of teuthology that could be left up to a separate service

  • To avoid teuthology users having to request, obtain and safeguard the private key that nsupdate requires to function

  • Because we use one subdomain for all of Sepia’s test nodes, we had to enable dynamic DNS for that whole zone (this is a limitation of bind). However, we do not want users to be able to push DNS updates for the entire zone. Instead, we gave nsupdate-web the ability to accept or reject requests based on whether the hostname matches a configurable regular expression. The private key itself is not shared with non-admin users.


At this time, only OVH has been tested as a provider. PRs are welcome to support more!