Inspection hooks

Inspection hooks are a type of the Bare Metal service plug-ins responsible for processing data from in-band inspection. By configuring these hooks, an operator can fully customize the inspection processing phase. How the data is collected can be configured with inspection collectors.

Configuring hooks

Two configuration options are responsible for inspection hooks: inspector.default_hooks defines which hooks run by default, while inspector.hooks defines which hooks to run in your deployment. Only the second option should be modified by operators, while the first one is to provide the defaults without hardcoding them:

hooks = $default_hooks

To make a hook run after the default ones, append it to the list, e.g.

hooks = $default_hooks,extra-hardware

Default hooks

In the order they go in the inspector.default_hooks option:


Processes the error field from the ramdisk, aborting inspection if it is not empty.


Validates network interfaces and stores the result in the plugin_data in two fields:

  • all_interfaces - all interfaces that pass the basic sanity check.

  • valid_interfaces - interfaces that satisfy the configuration in the inspector.add_ports option.

In both cases, interfaces get an addition field:

  • pxe_enabled - whether PXE was enabled on this interface during the inspection boot.


Creates ports for interfaces in valid_interfaces as set by the validate-interfaces hook.

Deletes ports that don’t match the inspector.keep_ports setting.


Populates the cpu_arch property on the node.

Optional hooks


Populates the accelerators property based on the reported PCI devices. The known accelerators are specified in the YAML file linked in the inspector.known_accelerators option. The default file is the following:

  - vendor_id: "10de"
    device_id: "1eb8"
    type: GPU
    device_info: NVIDIA Corporation Tesla T4
  - vendor_id: "10de"
    device_id: "1df6"
    type: GPU
    device_info: NVIDIA Corporation GV100GL

Sets the boot_mode capability based on the observed boot mode, see Boot mode support.


Uses the CPU flags to discover CPU capabilities. The exact mapping can be customized via configuration:

cpu_capabilities = vmx:cpu_vt,svm:cpu_vt

See inspector.cpu_capabilities for the default mapping.


Converts the data collected by python-hardware from its raw format into nested dictionaries under the extra plugin data field.


Uses the LLDP information from the ramdisk to populate the local_link_connection field on ports with the physical switch information.


Populates the memory_mb property based on physical RAM information from DMI.


Parses the raw binary LLDP information from the ramdisk and populates the parsed_lldp dictionary in plugin data. The keys are network interface names, the values are dictionaries with LLDP values. Example:

"parsed_lldp": {
    "eth0": {
        "switch_chassis_id": "11:22:33:aa:bb:cc",
        "switch_system_name": "sw01-dist-1b-b12"

Populates the capabilities based on PCI devices. The mapping is provided by the inspector.pci_device_alias option.


Populates the physical_network port field for Multi-tenancy in the Bare Metal service based on the detected IP addresses. The mapping is provided by the inspector.physical_network_cidr_map option.


Detects the newly created RAID device and populates the root_device property used in root device hints. Requires two inspections: one before and one after the RAID creation.


Uses root device hints on the node and the storage device information from the ramdisk to calculate the expected root device and populate the local_gb property (taking the inspector.disk_partitioning_spacing option into account).