Enabling drivers and hardware types

Introduction

The Bare Metal service delegates actual hardware management to drivers. Drivers, also called hardware types, consist of hardware interfaces: sets of functionality dealing with some aspect of bare metal provisioning in a vendor-specific way. There are generic hardware types (eg. redfish and ipmi), and vendor-specific ones (eg. ilo and irmc).

Note

Starting with the Rocky release, the terminologies driver, dynamic driver, and hardware type have the same meaning in the scope of Bare Metal service.

Enabling hardware types

Hardware types are enabled in the configuration file of the ironic-conductor service by setting the enabled_hardware_types configuration option, for example:

[DEFAULT]
enabled_hardware_types = ipmi,redfish

Due to the driver’s dynamic nature, they also require configuring enabled hardware interfaces.

Note

All available hardware types and interfaces are listed in setup.cfg file in the source code tree.

Enabling hardware interfaces

There are several types of hardware interfaces:

bios

manages configuration of the BIOS settings of a bare metal node. This interface is vendor-specific and can be enabled via the enabled_bios_interfaces option:

[DEFAULT]
enabled_hardware_types = <hardware_type_name>
enabled_bios_interfaces = <bios_interface_name>

See BIOS Configuration for details.

boot

manages booting of both the deploy ramdisk and the user instances on the bare metal node. See Boot interfaces for details.

Boot interface implementations are often vendor specific, and can be enabled via the enabled_boot_interfaces option:

[DEFAULT]
enabled_hardware_types = ipmi,ilo
enabled_boot_interfaces = pxe,ilo-virtual-media

Boot interfaces with pxe in their name require Configuring PXE and iPXE. There are also a few hardware-specific boot interfaces - see Drivers, Hardware Types and Hardware Interfaces for their required configuration.

console

manages access to the serial console of a bare metal node. See Configuring Web or Serial Console for details.

deploy

defines how the image gets transferred to the target disk. See Deploy Interfaces for an explanation of the difference between supported deploy interfaces direct and iscsi.

The deploy interfaces can be enabled as follows:

[DEFAULT]
enabled_hardware_types = ipmi,redfish
enabled_deploy_interfaces = iscsi,direct

Additionally,

inspect

implements fetching hardware information from nodes. Can be implemented out-of-band (via contacting the node’s BMC) or in-band (via booting a ramdisk on a node). The latter implementation is called inspector and uses a separate service called ironic-inspector. Example:

[DEFAULT]
enabled_hardware_types = ipmi,ilo,irmc
enabled_inspect_interfaces = ilo,irmc,inspector

See Hardware Inspection for more details.

management

provides additional hardware management actions, like getting or setting boot devices. This interface is usually vendor-specific, and its name often matches the name of the hardware type (with ipmitool being a notable exception). For example:

[DEFAULT]
enabled_hardware_types = ipmi,redfish,ilo,irmc
enabled_management_interfaces = ipmitool,redfish,ilo,irmc

Using ipmitool requires Configuring IPMI support. See Drivers, Hardware Types and Hardware Interfaces for the required configuration of each driver.

network

connects/disconnects bare metal nodes to/from virtual networks. See Configure tenant networks for more details.

power

runs power actions on nodes. Similar to the management interface, it is usually vendor-specific, and its name often matches the name of the hardware type (with ipmitool being again an exception). For example:

[DEFAULT]
enabled_hardware_types = ipmi,redfish,ilo,irmc
enabled_power_interfaces = ipmitool,redfish,ilo,irmc

Using ipmitool requires Configuring IPMI support. See Drivers, Hardware Types and Hardware Interfaces for the required configuration of each driver.

raid

manages building and tearing down RAID on nodes. Similar to inspection, it can be implemented either out-of-band or in-band (via agent implementation). See RAID Configuration for details. For example:

[DEFAULT]
enabled_hardware_types = ipmi,redfish,ilo,irmc
enabled_raid_interfaces = agent,no-raid
storage

manages the interaction with a remote storage subsystem, such as the Block Storage service, and helps facilitate booting from a remote volume. This interface ensures that volume target and connector information is updated during the lifetime of a deployed instance. See Boot From Volume for more details.

This interface defaults to a noop driver as it is considered an “opt-in” interface which requires additional configuration by the operator to be usable.

For example:

[DEFAULT]
enabled_hardware_types = ipmi,irmc
enabled_storage_interfaces = cinder,noop
vendor

is a place for vendor extensions to be exposed in API. See Vendor Methods for details.

[DEFAULT]
enabled_hardware_types = ipmi,redfish,ilo,irmc
enabled_vendor_interfaces = ipmitool,no-vendor

Here is a complete configuration example, enabling two generic protocols, IPMI and Redfish, with a few additional features:

[DEFAULT]
enabled_hardware_types = ipmi,redfish
enabled_boot_interfaces = pxe
enabled_console_interfaces = ipmitool-socat,no-console
enabled_deploy_interfaces = iscsi,direct
enabled_inspect_interfaces = inspector
enabled_management_interfaces = ipmitool,redfish
enabled_network_interfaces = flat,neutron
enabled_power_interfaces = ipmitool,redfish
enabled_raid_interfaces = agent
enabled_storage_interfaces = cinder,noop
enabled_vendor_interfaces = ipmitool,no-vendor

Note that some interfaces have implementations named no-<TYPE> where <TYPE> is the interface type. These implementations do nothing and return errors when used from API.

Hardware interfaces in multi-conductor environments

When enabling hardware types and their interfaces, make sure that for every enabled hardware type, the whole set of enabled interfaces matches for all conductors. However, different conductors can have different hardware types enabled.

For example, you can have two conductors with the following configuration respectively:

[DEFAULT]
enabled_hardware_types = ipmi
enabled_deploy_interfaces = direct
enabled_power_interfaces = ipmitool
enabled_management_interfaces = ipmitool

[DEFAULT]
enabled_hardware_types = redfish
enabled_deploy_interfaces = iscsi
enabled_power_interfaces = redfish
enabled_management_interfaces = redfish

But you cannot have two conductors with the following configuration respectively:

[DEFAULT]
enabled_hardware_types = ipmi,redfish
enabled_deploy_interfaces = direct
enabled_power_interfaces = ipmitool,redfish
enabled_management_interfaces = ipmitool,redfish

[DEFAULT]
enabled_hardware_types = redfish
enabled_deploy_interfaces = iscsi
enabled_power_interfaces = redfish
enabled_management_interfaces = redfish

This is because the redfish hardware type will have different enabled deploy interfaces on these conductors. It would have been fine, if the second conductor had enabled_deploy_interfaces = direct instead of iscsi.

This situation is not detected by the Bare Metal service, but it can cause inconsistent behavior in the API, when node functionality will depend on which conductor it gets assigned to.

Note

We don’t treat this as an error, because such temporary inconsistency is inevitable during a rolling upgrade or a configuration update.

Configuring interface defaults

When an operator does not provide an explicit value for one of the interfaces (when creating a node or updating its driver), the default value is calculated as described in Defaults for hardware interfaces. It is also possible to override the defaults for any interfaces by setting one of the options named default_<IFACE>_interface, where <IFACE> is the interface name. For example:

[DEFAULT]
default_deploy_interface = direct
default_network_interface = neutron

This configuration forces the default deploy interface to be direct and the default network interface to be neutron for all hardware types.

The defaults are calculated and set on a node when creating it or updating its hardware type. Thus, changing these configuration options has no effect on existing nodes.

Warning

The default interface implementation must be configured the same way across all conductors in the cloud, except maybe for a short period of time during an upgrade or configuration update. Otherwise the default implementation will depend on which conductor handles which node, and this mapping is not predictable or even persistent.

Warning

These options should be used with care. If a hardware type does not support the provided default implementation, its users will have to always provide an explicit value for this interface when creating a node.