Preseed configuration options¶

MicroCloud preseed allows the unattended (non-interactive) deployment of a cluster using a pre-configured file. See below for detailed descriptions of the main building blocks of the file, followed by a full configuration example file.

Storage disk filters¶

Explicitly setting the storage disks per system under systems.[*].storage is optional. Use filters if the exact disk paths are unknown when crafting the preseed file. This also makes the preseed file generic enough to be usable across various MicroCloud deployments.

Filters allow MicroCloud to make a selection from a list of all disks available on the systems. These filters correspond to the YAML field names of the disk resources returned from LXD’s /1.0/resources endpoint.

The following table lists all of the available filters:

Filter	Example
`id`	`nvme0n1`
`device`	`259:0`
`model`	`<Vendor>`
`type`	`nvme`
`read_only`	`false`
`mounted`	`false`
`size`	`1024209543168` (size of the disk in bytes)
`removable`	`false`
`wwn`	`eui.00xxxxxxxxxxxxxx`
`numa_node`	`0`
`device_path`	`pci-0000:04:00.0-nvme-1`
`block_size`	`512`
`firmware_version`	`4L2XXXXX`
`rpm`	`0`
`serial`	`S7XKXXXXXXXXXX`
`device_id`	`nvme-eui.00xxxxxxxxxxxxxx`
`pci_address`	`0000:04:00.0`
`used_by`	`bcache`

When using the size filter, its value can be compared against a user-defined number using byte suffixes in either units of 1000 or 1024:

B, kB, MB, GB, TB, EB, KiB, MiB, GiB, TiB, PiB, EiB

Filter operands¶

All filters can use the following operands to compare against defined values:

&&, ||, <, >, <=, >=, ==, !=, !

Furthermore the following restrictions apply:

Filters are checked in order of appearance
String values must not be in quotes unless the string contains a space
Single quotes are fine, but double quotes must be escaped

Multiple filters can be added to a single section:

storage:
  ceph:
    - find: <filters>
    - find: <filters>

Limit filtered disks¶

In addition to finding disks by filter, the minimum and maximum number of disks can also be specified. For this, the find_min and find_max settings can be added to the relevant section:

storage:
  ceph:
    - find: <filters>
      find_min: 1
      find_max: 2

The example above will make sure that the filters select at least one, but not more than two, disks for remote (Ceph) storage.

Note

For local storage there can only ever be one disk per system. If the filters return more than one disk, only one of them will be used.

For remote storage the filters apply for all disks across all systems.

Full configuration example¶

The preseed YAML file must use the following syntax:

# `initiator` defines which system takes over the role of the initiator during the trust establishment using multicast discovery.
# Make sure to also set `lookup_subnet`.
# The field cannot be set together with `initiator_address`.
# Required if `initiator_address` isn't specified.
initiator: micro01

# `initiator_address` defines which system takes over the role of the initiator during the trust establishment.
# It also allows joining systems to learn about the address they have to connect to.
# The field cannot be set together with `initiator`.
# Required if `initiator` isn't specified.
initiator_address: 10.0.0.1

# `lookup_subnet` is required and limits the subnet when looking up systems using multicast discovery.
# The first assigned address of this subnet is used for MicroCloud itself.
lookup_subnet: 10.0.0.0/24

# `lookup_timeout` is optional and configures how long the joining system will wait for a system to be discovered using multicast discovery.
# The value has to be provided in seconds.
# It defaults to 60 seconds.
lookup_timeout: 300

# `session_passphrase` is required and configures the passphrase used during the trust establishment session.
session_passphrase: 83P27XWKbDczUyE7xaX3pgVfaEacfQ2qiQ0r6gPb

# `session_timeout` is optional and configures how long the trust establishment session will last.
# The value has to be provided in seconds.
# It defaults to 60 minutes.
session_timeout: 300

# `systems` is required and lists the systems we expect to find by their host name.
#   `name` is required and represents the host name.
#   `address` sets the address used for MicroCloud and is required in case `initiator_address` is present.
#   `ovn_uplink_interface` is optional and represents the name of the interface reserved for use with OVN.
#   `ovn_underlay_ip` is optional and represents the Geneve Encap IP for each system.
#   `storage` is optional and represents explicit paths to disks for each system.
systems:
- name: micro01
  address: 10.0.0.1
  ovn_uplink_interface: eth1
  ovn_underlay_ip: 10.0.2.101
- name: micro02
  address: 10.0.0.2
  ovn_uplink_interface: eth1
  ovn_underlay_ip: 10.0.2.102
  storage:
    local:
      path: /dev/nvme5n1
      wipe: true
    ceph:
      - path: /dev/nvme4n1
        wipe: true
      - path: nvme3n1
        wipe: true
        encrypt: true
- name: micro03
  address: 10.0.0.3
  ovn_uplink_interface: eth1
  ovn_underlay_ip: 10.0.2.103
- name: micro04
  address: 10.0.0.4
  ovn_uplink_interface: eth1

# `ceph` is optional and represents the Ceph global configuration
# `cephfs: true` can be used to optionally set up a CephFS file system alongside Ceph distributed storage.
# `internal_network: subnet` optionally specifies the internal cluster network for the Ceph cluster. This network handles OSD heartbeats, object replication, and recovery traffic.
# `public_network: subnet` optionally specifies the public network for the Ceph cluster. This network conveys information regarding the management of your Ceph nodes. It is by default set to the MicroCloud lookup subnet.
ceph:
  cephfs: true
  internal_network: 10.0.1.0/24
  public_network: 10.0.0.0/24

# `ovn` is optional and represents the OVN & uplink network configuration for LXD.
ovn:
  ipv4_gateway: 192.0.2.1/24
  ipv4_range: 192.0.2.100-192.0.2.254
  ipv6_gateway: 2001:db8:d:200::1/64
  dns_servers: 192.0.2.1,2001:db8:d:200::1

# `storage` is optional and is used as basic filtering logic for finding disks across all systems.
# Filters will only apply to systems which do not have an explicitly defined disk above for the corresponding storage type.
# Filters are checked in order of appearance.
# The names and values of each key correspond to the YAML field names for the `api.ResouresStorageDisk`
# struct here:
# https://github.com/canonical/lxd/blob/c86603236167a43836c2766647e2fac97d79f899/shared/api/resource.go#L591
# Supported operands: &&, ||, <, >, <=, >=, ==, !=, !
# String values must not be in quotes unless the string contains a space.
# Single quotes are fine, but double quotes must be escaped.
# `find_min` and `find_max` can be used to validate the number of disks each filter finds.
storage:
  local:
    - find: size > 10GiB && size < 50GiB && type == nvme
      find_min: 1
      find_max: 1
      wipe: true
    - find: size > 10GiB && size < 50GiB && type == hdd && block_size == 512 && model == 'Samsung %'
      find_min: 3
      find_max: 3
      wipe: false
  ceph:
    - find: size > 10GiB && size < 50GiB && type == nvme
      find_min: 1
      find_max: 2
      wipe: true
    - find: size > 10GiB && size < 50GiB && type == hdd && block_size == 512 && model == 'Samsung %'
      find_min: 3
      find_max: 8
      wipe: false