The data source LXD allows the user to provide custom user-data, vendor-data, meta-data and network-config to the instance without running a network service (or even without having a network at all). This datasource performs HTTP GETs against the LXD socket device which is provided to each running LXD container and VM as /dev/lxd/sock and represents all instance-metadata as versioned HTTP routes such as:

  • 1.0/meta-data

  • 1.0/config/user.meta-data

  • 1.0/config/user.vendor-data

  • 1.0/config/user.user-data

  • 1.0/config/user.<any-custom-key>

The LXD socket device /dev/lxd/sock is only present on containers and VMs when the instance configuration has security.devlxd=true (default). Disabling security.devlxd configuration setting at initial launch will ensure that cloud-init uses the NoCloud datasource. Disabling security.devlxd over the life of the container will result in warnings from cloud-init and cloud-init will keep the originally detected LXD datasource.

The LXD datasource is detected as viable by ds-identify during systemd generator time when either /dev/lxd/sock exists or /sys/class/dmi/id/board_name matches “LXD”.

The LXD datasource provides cloud-init the ability to react to meta-data, vendor-data, user-data and network-config changes and render the updated configuration across a system reboot.

To modify what meta-data, vendor-data or user-data are provided to the launched container, use either LXD profiles or lxc launch ... -c <key>="<value>" at initial container launch setting one of the following keys:

  • user.meta-data: YAML metadata which will be appended to base meta-data

  • user.vendor-data: YAML which overrides any meta-data values

  • user.network-config: YAML representing either Networking Config Version 1 or Networking Config Version 2 format

  • user.user-data: YAML which takes preference and overrides both meta-data and vendor-data values

  • user.any-key: Custom user configuration key and value pairs can be passed to cloud-init. Those keys/values will be present in instance-data which can be used by both #template: jinja #cloud-config templates and the cloud-init query command.

Note: LXD version 4.22 introduced a new scope of config keys prefaced by cloud-init. which are preferred above the related user.* keys:

  • cloud-init.meta-data

  • cloud-init.vendor-data

  • cloud-init.network-config

  • cloud-init.user-data

By default, network configuration from this datasource will be:

version: 1
    - type: physical
      name: eth0
          - type: dhcp
            control: auto

This datasource is intended to replace NoCloud datasource for LXD instances with a more direct support for LXD APIs instead of static NoCloud seed files.