LXDΒΆ

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

One can manipulate what meta-data, vendor-data or user-data is provided to the launched container using the LXD profiles or lxc launch ... -c <key>="<value>" at initial container launch using 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.

By default, network configuration from this datasource will be:

version: 1
config:
    - type: physical
      name: eth0
      subnets:
          - 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.