The document discusses the Ironic Inspector service, which discovers hardware properties of bare metal nodes through introspection. It describes the general workflow where a node is enrolled, brought to a manageable state, and has its hardware inventory collected by booting an Ironic Python Agent ramdisk. The collected data is processed by plugins, stored in Swift according to introspection rules, and used to update the node's properties. It also covers capabilities detection, optional collectors like Dmidecode and Biosdevname, and CLI commands for managing introspection.

1. Bare Metal Introspection service
(ironic-inspector)
Annie Lezil
Ramamani Yeleswarapu

2. AGENDA
● Ironic Inspector
● Workflow
● Plugins/ Collectors
● Introspection Rules & Reapplying Introspection
● Capabilities
● Biosdevname & Dmidecode collectors

3. IRONIC INSPECTOR
● Service for discovering hardware properties of a node
● Properties required for scheduling a bare metal node
● Inspection involves booting Ironic Python Agent(IPA) ramdisk on the node
● IPA - agent running in the ramdisk to control and deploy nodes
● Inspection requires configuring the IPA ramdisk, PXE/iPXE boot environments

4. GENERAL WORKFLOW
Enroll a node
(IPMI Credentials)
Bring node to
manageable
state
(CLI command)
Request node
inspection
(CLI command)
Inspector validates node
(power credentials,
power and provision states)
Inspector allows firewall
access
(PXE boot services for the
node)
Issues reboot command
(IPA boots on the node)
IPA collects the HW info
(post it back data to the
Inspector)
Inspector figures out
the node the data
belongs to
Inspector processes
the data
(updates the node’s
DB)
Inspector stores
HW inventory in
Swift

5. INSTALL / CONTRIBUTION

6. USAGE
● Node States
● Introspection Rules
● Reapplying Introspection on
Stored Data
● Discovery
● Capabilities Detection
● Plugins

7. NODE STATES
● The nodes should be moved to MANAGEABLE provision state before introspection.
● Move node to manageable state:
“openstack baremetal node manage <UUID>”
“ironic node-set-provision-state <node_UUID> manage”
● INSPECT a node:
“openstack baremetal node inspect <UUID>”
“openstack baremetal introspection start <UUID>”
“ironic node-set-provision-state <node_UUID> inspect”
● Get back a data in json file and store it in Swift:
“openstack baremetal introspection data save <UUID>”
● After successful introspection and before deploying nodes should be made available to Nova, by moving them to
AVAILABLE state:
“openstack baremetal node provide <UUID>”
“ironic node-set-provision-state <UUID> provide”
manageable
enroll
available
manage
(via API)
provide
(via API)
manage
(via API)
Inspection
inspect
(via API)

8. PLUGINS
● For data processing including standard functionality
● Plugins enabled by default:
scheduler, validate_interfaces, root_disk_selection, ramdisk_error, capabilities, pci_devices
● Optional plugins:
example, raid_device, local_link_connection, lldp_basic
● Set in ironic.conf:
processing_hooks
default_processing_hooks

9. PLUGINS
Receives data
from ramdisk
Run
pre-processing
hooks
Look up for node
Run
post-processing
hooks
Updates Ironic DBSaves data to Swift

10. INTROSPECTION RULES
● Operator/User creates “Conditions” on introspection data to perform “Action” on node.
● Simple JSON-based domain-specific language used to define rules.
Condition
{"field":"data://introspection.path,
"op": "eq", "value": "val"}
True
Action
{"action": "set-attribute",
"path":"/driver_info/ipmi_address",
"value": "{data[inventory][bmc_address]}"}
False Action not
performed

11. INTROSPECTION RULES EXAMPLES
● Save the conditions and actions as .json file.

12. INTROSPECTION RULES EXAMPLES

13. INTROSPECTION RULES EXAMPLES

14. REAPPLYING INTROSPECTION ON STORED DATA
Create/Import
Rules
Inspect
Reboots node
Collects data
Process the data
Applies the rules
Saves the data
in Swift
Reapply
Fetch data from
Swift
● Allows correcting mistakes
in introspection rules.
● Not necessary to inspect a
node if the rules created
are wrong.
● “openstack baremetal
introspection reprocess
<UUID>”

15. DISCOVERY
● Inspector can automatically enroll new nodes to Ironic
● Set “node_not_found_hook = enroll” in inspector.conf to load the
processing hook “enroll”
● Set "enroll_node_driver" option to the Ironic driver
● Node is manually booted without registering it with Ironic.
● Ramdisk is booted and data collected back to inspector.
● If inspector cannot find the node in ironic, it creates a new node.

16. CAPABILITIES DETECTION
● Currently, Inspector can discover these node capabilities:
○ Boot mode (current boot mode BIOS or UEFI)
○ Several CPU flags (cpu_aes, cpu_vt, cpu_txt, cpu_hugepages, cpu_hugepages_1g)
● Define your own rules by setting the [capabilities]/cpu_flags in
inspector.conf

17. CAPABILITIES DETECTION
Capabilities
added to
node’s
properties

18. CAPABILITIES DETECTION EXAMPLES
Nodes
should be
available

20. COLLECTORS in IPA
● Extensions of the inspection process during the IPA ramdisk run
● Adding a new collector requires rebuilding the IPA ramdisk and kernel images
● Using CoreOS/ TinyIPA/ Disk Image Builder
● Use the resulting .kernel and .initramfs files to set PXE/iPXE (.gz and .vmlinuz files in
the case of CoreOS/TinyIPA)
● Customize the list of collectors by appending to the kernel option in the
PXE/iPXE config:
ipa-inspection-collectors=default,logs,extra_hardware

21. DMIDECODE COLLECTOR
● Collects detailed output of dmidecode utility for processor, memory and bios
● Optional collector to be added to the ipa-inspection-collectors kernel argument
● Adds to the hardware inventory:

22. BIOSDEVNAME
● Biosdevname - utility that gives BIOS-given name of a device (interface).
● Default Collector - collects the hardware inventory of a node.
● Implementation:
○ Created the biosdevname utility for TinyIPA (ramdisk).
○ Implemented a function to collect the Bios given interface name and added it to interfaces
section of default collector.
Extra field
biosdevname
added

23. INTROSPECTION CLI COMMANDS
● baremetal introspection abort
● baremetal introspection data save
● baremetal introspection list
● baremetal introspection reprocess
● baremetal introspection rule delete
● baremetal introspection rule import
● baremetal introspection rule list
● baremetal introspection rule purge
● baremetal introspection rule show
● baremetal introspection start
● baremetal introspection status

24. Thank You