How to use profiles¶

Profiles store a set of configuration options. They can contain Instance options, Devices, and device options.

You can apply any number of profiles to an instance. They are applied in the order they are specified, so the last profile to specify a specific key takes precedence. However, instance-specific configuration always overrides the configuration coming from the profiles.

Note

Profiles can be applied to containers and virtual machines. Therefore, they might contain options and devices that are valid for either type.

When applying a profile that contains configuration that is not suitable for the instance type, this configuration is ignored and does not result in an error.

If you don’t specify any profiles when launching a new instance, the default profile is applied automatically. This profile defines a network interface and a root disk. The default profile cannot be renamed or removed.

View profiles¶

Enter the following command to display a list of all available profiles:

lxc profile list

Enter the following command to display the contents of a profile:

lxc profile show <profile_name>

To display all available profiles, send a request to the /1.0/profiles endpoint:

lxc query --request GET /1.0/profiles?recursion=1

To display a specific profile, send a request to that profile:

lxc query --request GET /1.0/profiles/<profile_name>

See GET /1.0/profiles and GET /1.0/profiles/{name} for more information.

Create an empty profile¶

Enter the following command to create an empty profile:

lxc profile create <profile_name>

To create an empty profile, send a POST request to the /1.0/profiles endpoint:

lxc query --request POST /1.0/profiles --data '{"name": "<profile_name>"}'

See POST /1.0/profiles for more information.

Edit a profile¶

You can either set specific configuration options for a profile or edit the full profile. See Instance configuration (and its subpages) for the available options.

Set specific options for a profile¶

To set an instance option for a profile, use the lxc profile set command. Specify the profile name and the key and value of the instance option:

lxc profile set <profile_name> <option_key>=<option_value> <option_key>=<option_value> ...

To add and configure an instance device for your profile, use the lxc profile device add command. Specify the profile name, a device name, the device type and maybe device options (depending on the device type):

lxc profile device add <profile_name> <device_name> <device_type> <device_option_key>=<device_option_value> <device_option_key>=<device_option_value> ...

To configure instance device options for a device that you have added to the profile earlier, use the lxc profile device set command:

lxc profile device set <profile_name> <device_name> <device_option_key>=<device_option_value> <device_option_key>=<device_option_value> ...

To set an instance option for a profile, send a PATCH request to the profile. Specify the key and value of the instance option under the "config" field:

lxc query --request PATCH /1.0/profiles/<profile_name> --data '{
  "config": {
    "<option_key>": "<option_value>",
    "<option_key>": "<option_value>"
  }
}'

To add and configure an instance device for your profile, specify the device name, the device type and maybe device options (depending on the device type) under the "devices" field:

lxc query --request PATCH /1.0/profiles/<profile_name> --data '{
  "devices": {
    "<device_name>": {
      "type": "<device_type>",
      "<device_option_key>": "<device_option_value>",
      "<device_option_key>": "<device_option_value>"
    }
  }
}'

See PATCH /1.0/profiles/{name} for more information.

Edit the full profile¶

Instead of setting each configuration option separately, you can provide all options at once.

Check the contents of an existing profile or instance configuration for the required fields. For example, the default profile might look like this:

config: {}
description: Default LXD profile
devices:
  eth0:
    name: eth0
    network: lxdbr0
    type: nic
  root:
    path: /
    pool: default
    type: disk
name: default
used_by:

Instance options are provided as an array under config. Instance devices and instance device options are provided under devices.

To edit a profile using your standard terminal editor, enter the following command:

lxc profile edit <profile_name>

Alternatively, you can create a YAML file (for example, profile.yaml) with the configuration and write the configuration to the profile with the following command:

lxc profile edit <profile_name> < profile.yaml

To update the entire profile configuration, send a PUT request to the profile:

lxc query --request PUT /1.0/profiles/<profile_name> --data '{
  "config": { ... },
  "description": "<description>",
  "devices": { ... }
}'

See PUT /1.0/profiles/{name} for more information.

Apply a profile to an instance¶

Enter the following command to apply a profile to an instance:

lxc profile add <instance_name> <profile_name>

Tip

Check the configuration after adding the profile: lxc config show <instance_name>

You will see that your profile is now listed under profiles. However, the configuration options from the profile are not shown under config (unless you add the --expanded flag). The reason for this behavior is that these options are taken from the profile and not the configuration of the instance.

This means that if you edit a profile, the changes are automatically applied to all instances that use the profile.

You can also specify profiles when launching an instance by adding the --profile flag:

lxc launch <image> <instance_name> --profile <profile> --profile <profile> ...

To apply a profile to an instance, add it to the profile list in the instance configuration:

lxc query --request PATCH /1.0/instances/<instance_name> --data '{
  "profiles": [ "default", "<profile_name>" ]
}'

See PATCH /1.0/instances/{name} for more information.

You can also specify profiles when creating an instance:

lxc query --request POST /1.0/instances --data '{
  "name": "<instance_name>",
  "profiles": [ "default", "<profile_name>" ],
  "source": {
    "alias": "<image_alias>",
    "protocol": "simplestreams",
    "server": "<server_URL>",
    "type": "image"
  }
}'

Remove a profile from an instance¶

Enter the following command to remove a profile from an instance:

lxc profile remove <instance_name> <profile_name>

To remove a profile from an instance, send a PATCH request to the instance configuration with the new profile list. For example, to revert back to using only the default profile:

lxc query --request PATCH /1.0/instances/<instance_name> --data '{
  "profiles": [ "default" ]
}'

See PATCH /1.0/instances/{name} for more information.