MAAS 2.5.0 alpha 2 released!

MAAS 2.5.0 (alpha2)

Important announcements

MAAS architectural and high-availability changes

MAAS 2.5 introduces several improvements that change the interaction between controllers and machines. More specifically:

  • Communication will now be proxied through the rack controllers. Machines will no longer communicate with the region controller directly.
  • Rack-to-region configuration no longer needs VIPs for HA environments.

For more details, please read the following section, and refer to MAAS 2.5.0 alpha 1 release notes.

New features & improvements

Proxying communication through the rack controller

Starting with MAAS 2.5, all machine communication to MAAS will be through the rack controller. As of 2.5.0 alpha 1, MAAS uses a proxy for HTTP (metadata) and DNS communication. As of 2.5.0 alpha 2, two more changes have been introduced:

  • MAAS now creates an internal DNS domain (not manageable by the user) and a special DNS resource for each subnet that is managed by MAAS. Each subnet will include all rack controllers that have an IP address on that subnet. Booting machines will use the subnet DNS resource to resolve the rack controller available for communication. In the case that multiple rack controllers belong to the same subnet, MAAS will use a round-robin algorithm to balance the load across multiple rack controllers.

  • Proxy (squid) is now done through the rack controller. Newly deployed machines using the MAAS built-in proxy will be configured to use the internal DNS resource for the subnet they have been deployed to. This ensures machines always have a controller, using multiple controllers in round-robin DNS when available.

In a future release, deployed machines will proxy syslog messages through the rack controller.


MAAS 2.5.0 alpha 2 introduces the ability to compose KVM virtual machines (from a “Pod”) with interfaces. Users of the API, using either the machines allocate endpoint or the pod compose endpoint, are now able to include an interfaces constraint, allowing the selection of KVM pod NICs.

If the interfaces constraint is left unspecified, MAAS 2.5.0 will maintain backward compatibility with earlier releases by first checking for a maas network, then a default network for attachment to the KVM pod.

If the interfaces constraint is specified, MAAS will create a bridge or macvlan attachment to the networks that match the constraints. MAAS will prefer bridge interface attachments when possible, since this typically results in successful communication. For example, consider the following constraint:


In this case, assuming the KVM pod is deployed on a machine or controller with access to the maas and storage spaces, MAAS will create an eth0 interface bound to the maas space, and an eth1 interface bound to the storage space.

If constraints are specified as follows, MAAS will assign unallocated IP addresses:


In this case, MAAS will automatically convert the ip constraint to a VLAN constraint (for the VLAN where its subnet can be found), and assign the IP address to the newly-composed machine upon allocation.

The ability to compose VMs using the Web UI with the new interface parameters is not yet complete and is expected in a subsequent release of MAAS 2.5.0.

Web UI

The MAAS 2.5.0 alpha 2 UI has been refreshed::

  • On deployment, the Machine listing page now includes the IP address assigned to the machine.
  • The latest Vanilla framework provides fine-grain control of spacing and padding, allowing more information to be displayed in less space.
  • Interactions and forms are more consistent throughout UI.


MAAS can now deploy ESXi. The first supported release is ESXi 6.7. Given that ESXi is a special case, deployment support is similar to our Windows support.

  • Network configuration is not yet supported. MAAS 2.5.0 will provide basic networking configuration, which includes static-IP address configuration on non-VLAN or Bonded interfaces. Future versions of MAAS will support NIC Teaming and VLANs.

  • Post-installation customization is not available over preseeds (e.g. curtin_userdata). Users can customize the image they create to deploy with MAAS.

For more information on how to deploy ESXi, please contact Canonical (

Known issues & workarounds

It has been discovered that in some situations the DHCP configuration doesn’t get correctly updated with the hostmap for a deploying machine. We have take measures to address the issue, but if you are able to reproduce, please update the bug report.

Bug fixes

Please refer to the following for all bug fixes in this release.


MAAS 2.5.0 alpha 2 can be installed from our PPA as follows:

sudo apt-add-repository ppa:maas/next
sudo apt install maas