A simple Terraform provider for MAAS. This is a work in progress and by no means should be considered production quality work. The current version supports the allocation, power up, power down and release of nodes already registered with MAAS. I think this is the main usage for MAAS and will cover the majority of use cases out there. I'll look into adding more functionality in the future.

• Terraform
• Go MAAS API Library

The provider requires some variables to be configured in order to gain access to the MAAS server:

• api_version: This is optional and probably only works with 2.0. The defaults to 2.0.
• api_key: MAAS API Key
• api_url: URI for your MAAS API server (eg https://127.0.0.1:80/MAAS)

provider "maas" {
  api_version = "2.0"
  api_key = "YOUR MAAS API KEY"
  api_url = "https://<MAAS_SERVER>[:MAAS_PORT]/MAAS"
}

This provider is only able to deploy and release nodes already registered and configured in MAAS. The selection mechanism for the nodes is a subset of criteria described in the [MAAS API]https://maas.ubuntu.com/docs/api.html#nodes. Currently, this provider supports:

• hostnames: Host name to try to allocate.
• architecture: Architecture of the requested machine: ie: amd64/generic
• cpu_count: The minimum number of cpu cores needed for consideration
• memory: Minimum amount of RAM neede for consideration
• tags: List of tags to use in the selection process

The above constraints parameters can be used to acquire a node that possesses certain characteristics. All the constraints are optional and when multiple constraints are provided, they are combined using ‘AND’ semantics. In the absence of any constraints, a random node will be selected and deployed. The examples in the next section attempt to explain how to use the resource.

resource "maas_instance" "maas_single_random_node" {
  count = 1
}

resource "maas_instance" "maas_three_random_nodes" {
  count = 3
}

resource "maas_instance" "maas_node_1" {
  hostname = "node-1"
}

resource "maas_instance" "maas_three_nodes_8g" {
  memory = "8G"
  count = 3
}

Configures a physical interface on a system, where a system is anything with a system ID.

resource "maas_interface_physical" "myserver_eth0" {
  system_id   = maas_instance.myserver.system_id
  name        = "eth0"
  mac_address = "01:23:45:67:89:0A"
  tags        = ["foo", "bar"]
  vlan        = "my_vlan"
  mtu         = 1500
  accept_ra   = true
  autoconf    = true
}

The system_id and mac_address parameters are required.

An interface can be uniquely identified by its system ID and interface id (which is an integer).

terraform import maas_interface_physical.my_eth 3xtkyg:23

Configures a link between physical interface on a system and a subnet.

resource "maas_interface_link" "eth0_sn123" {
  system_id    = maas_interface_physical.myserver.system_id
  interface_id = maas_interface_physical.myserver.interface_id
  subnet_id    = 123
  mode         = "STATIC"
  ip_address   = "::1"
  force        = true
}

Mode definitions:

• AUTO: Assign this interface a static IP address from the provided subnet. The subnet must be a managed subnet. The IP address will not be assigned until the node goes to be deployed.
• DHCP: Bring this interface up with DHCP on the given subnet. Only one subnet can be set to DHCP. If the subnet is managed this interface will pull from the dynamic IP range.
• STATIC: Bring this interface up with a static IP address on the given subnet. Any number of static links can exist on an interface.
• LINK_UP: Bring this interface up only on the given subnet. No IP address will be assigned to this interface. The interface cannot have any current AUTO, DHCP or STATIC links.

The system_id, interface_id, and subnet_id parameters are required.

A link can be uniquely identified by a combination of its system ID, interface ID, and the ID of the subnet connected by the link.

terraform import maas_interface_link.my_link 3xtkyg:23:42

Configure MaaS server parameters.

This resource currently only supports configuring NTP servers.

Search the MaaS API for a subnet. If there are multiple matches, the first one will be returned.

data "maas_subnet" "mynet" {
  name = "the_subnet"
  vlan = 123
  cidr = "192.168.0.0/24"
}

All parameters are optional. The first subnet that matches all specified parameters will be returned.

Besides the properties defined above, the following properties are also available:

rdns_mode values:

• 0 Disabled: No reverse zone is created.
• 1 Enabled: Generate reverse zone.
• 2 RFC2317: Extends '1' to create the necessary parent zone with the appropriate CNAME resource records for the network, if the the network is small enough to require the support described in RFC2317.

Search the MaaS API for a rack controller. If there are multiple matches, the first one will be returned.

data "maas_rack_controller" "ctrl" {
  domain = ".example.com"
  zone = "the_zone"
  pool = "foo"
}

All parameters are optional. The first subnet that matches all specified parameters will be returned.

User data can be either a cloud-init script or a bash shell

Header for cloud-init:

#cloud-config

Header for script (shebang):

#!/bin/bash

Example (read from file):

resource "maas_instance" "maas_single_random_node" {
  count = 1
  user_data = "${file("${path.module}/user_data/test_data.txt")}"
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  comment = "Platform deployment"
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  tags = ["DELL_R630", "APP_CLASS"]
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  deploy_hostname = "freedompants"
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  deploy_tags = ["hostwiththemost", "platform"]
}

Useful for custom OS builds

resource "maas_instance" "maas_single_random_node" {
  count = 1
  distro_series = "centos73"
}

Useful for choosing a particular kernel release train builds

resource "maas_instance" "maas_single_random_node" {
  count = 1
  distro_series = "bionic"
  hwe_kernel = "hwe-18.04"
}

Maas provides an option to erase the node's disk when releasing the system. By default it will not alter the disk. This provides a very quick method do release the system back into the pool of nodes. It isn't ideal to leave data on a disk as this may lead to data loss or even booting a system that may cause a service outage. With this in mind the Terraform provider is set to erase the disk on release. This ensures that the machine will be released into the pool with a clean state.

There are a few options when releasing a system:

• erase
  • The default setting
  • MAAS will overwrite the whole disk with null bytes. This can be very slow.
  • Estimated 20min
• secure erase
  • Requires the disk to support a secure erase option.
  • If the disk does not support secure erase it will default the erase option. MAAS will overwrite the whole disk with null bytes. This can be very slow.
  • Estimated 20min
• quick erase
  • Wipe 1MiB at the start and at the end of the drive to make data recovery inconvenient and unlikely to happen by accident. This is not secure.
  • Estimated 3min

The default option is to always perform an erase.

resource "maas_instance" "maas_single_random_node" {
  count = 1
}

This shows what is set by default in Terraform. You are not required to set this option.

resource "maas_instance" "maas_single_random_node" {
  count = 1
  release_erase = true
}

How to disable the disk erasure.

resource "maas_instance" "maas_single_random_node" {
  count = 1
  release_erase = false
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  release_erase_secure = true
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  release_erase_quick = true
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  install_kvm = true
}

resource "maas_instance" "maas_single_random_node" {
  count = 1
  install_rackd = true
}

If there are conflicting options, such as enabling both secure and quick erase, this is how the Maas API deals with conflicts.

If neither release_secure_erase nor release_quick_erase are specified, MAAS will overwrite the whole disk with null bytes. This can be very slow.

If both release_secure_erase and release_quick_erase are specified and the drive does NOT have a secure erase feature, MAAS will behave as if only quick_erase was specified.

If release_secure_erase is specified and release_quick_erase is NOT specified and the drive does NOT have a secure erase feature, MAAS will behave as if secure_erase was NOT specified, i.e. will overwrite the whole disk with null bytes. This can be very slow.

Source: Maas API: POST /api/2.0/machines/{system_id}/ op=release

This is just a basic (proof of concept) provider. The following are some of the features I would like to see here:

• All of the supported constratins for allocating and deploying a node
• Discover nodes
• Create new nodes
• Accept and commission nodes