How to customise machines

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MAAS allows machine customization before provisioning using Curtin or cloud-init.

Curtin pre-seeding

You can customize Curtin via the curtin_userdata template or by adding a custom file. Curtin supports early and late hooks for pre/post-installation customization.

• Early Command Example:

  early_commands:
    signal: ["wget", "--no-proxy", "http://example.com/", "--post-data", "system_id=&signal=starting_install", "-O", "/dev/null"]
  

• Late Commands Example:

  late_commands:
    add_repo: ["curtin", "in-target", "--", "add-apt-repository", "-y", "ppa:my/ppa"]
    custom: ["curtin", "in-target", "--", "sh", "-c", "/bin/echo -en 'Installed ' > /tmp/maas_system_id"]
  

Cloud-init pre-seeding

To customize cloud-init:

• MAAS 3.4+ UI:
  Machines > machine > Actions > Deploy > Cloud-init user-data > enter customizations > Start deployment.

• Other versions UI:
  Take action > Deploy > > Cloud-init user-data > enter customizations > Start deployment.

• CLI:

  maas $PROFILE machine deploy $SYSTEM_ID user_data=<base-64-encoded-script>
  

Set default minimum kernel

To set the default kernel for all machines:

• MAAS 3.4+ UI:
  Settings > Configuration > Commissioning > Default minimum kernel version > Save.

• Other versions UI:
  Settings > General > Default minimum kernel version > Save.

• CLI:

  maas $PROFILE maas set-config name=default_min_hwe_kernel value=$KERNEL
  

Set minimum kernel per machine

To set a minimum deployment kernel for a specific machine:

• MAAS UI:
  Machines > machine > Configuration > Edit > Minimum kernel.

• CLI:

  maas $PROFILE machine update $SYSTEM_ID min_hwe_kernel=$HWE_KERNEL
  

Set specific kernel during deployment

To set a kernel during deployment:

• MAAS UI:
  Machines > machine > Take action > Deploy > choose kernel > Deploy machine.

• CLI:

  maas $PROFILE machine deploy $SYSTEM_ID distro_series=$SERIES hwe_kernel=$KERNEL
  

Set global kernel boot options

To set global kernel boot options:

• MAAS 3.4+ UI:
  Settings > Kernel parameters > enter options > Save.

• Other versions UI:
  Settings > General > enter options > Save.

• CLI:

  maas $PROFILE maas set-config name=kernel_opts value='$KERNEL_OPTIONS'
  

Kernel option tags

To create a tag with kernel options:

maas $PROFILE tags create name='$TAG_NAME' comment='$TAG_COMMENT' kernel_opts='$KERNEL_OPTIONS'

View tags:

maas admin tags read | jq -r '(["tag_name","tag_comment","kernel_options"] |(.,map(length*"-"))),(.[]|[.name,.comment,.kernel_opts]) | @tsv' | column -t

Enable hardware sync (MAAS 3.2+)

To enable hardware sync:

• MAAS 3.4+ UI:
  Machines > machine > Actions > Deploy > Periodically sync hardware > Start deployment.

• Other versions UI:
  Take action > Deploy > Periodically sync hardware > Start deployment.

• CLI:

  maas $PROFILE machine deploy $SYSTEM_ID osystem=$OSYSTEM distro_series=$VERSION enable_hw_sync=true
  

View Hardware Sync Updates

View updates in the MAAS UI or CLI:

maas $PROFILE machine read $SYSTEM_ID

Configure Hardware Sync Interval

Configure the sync interval in MAAS settings.

Set default layout

To set the default storage layout for all machines:

• MAAS UI:

  1. Settings > Storage > choose default layout.
  2. Enable Erase machines’ disks prior to releasing to force disk erasure.

• CLI:

  maas $PROFILE maas set-config name=default_storage_layout value=$LAYOUT_TYPE
  

  Example for setting layout to flat:

  maas $PROFILE maas set-config name=default_storage_layout value=flat
  

Set per-machine layout

Set a storage layout for a ‘Ready’ machine:

maas $PROFILE machine set-storage-layout $SYSTEM_ID storage_layout=$LAYOUT_TYPE [$OPTIONS]

Example with LVM layout:

maas $PROFILE machine set-storage-layout $SYSTEM_ID storage_layout=lvm lv_size=5368709120

Erase disks

To erase a disk when releasing a machine:

• Use machine release (singular) instead of machines release (plural).

Example:

maas $PROFILE machine release $SYSTEM_ID comment="some comment" erase=true [secure_erase=true || quick_erase=true]

• Secure erasure uses the drive’s secure erase feature, if available.
• Quick erasure wipes 2MB at the start and end of the disk. Not secure but faster.
• If no options are specified, the disk will be overwritten with null bytes (slow).

Set conditional erasure

To perform secure erasure if available, or quick erasure otherwise:

maas $PROFILE machine release $SYSTEM_ID comment="some comment" erase=true secure_erase=true quick_erase=true

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Last updated a month ago.