How To Contribute


  • Our source code is hosted on OpenStack GitHub, but please do not send pull requests there.

  • Please follow usual OpenStack Gerrit Workflow to submit a patch.

  • Update change log in README.rst on any significant change.

  • It goes without saying that any code change should by accompanied by unit tests.

  • Note the branch you’re proposing changes to. master is the current focus of development, use stable/VERSION for proposing an urgent fix, where VERSION is the current stable series. E.g. at the moment of writing the stable branch is stable/1.0.

  • Please file an RFE in StoryBoard for any significant code change and a regular story for any significant bug fix.

Development Environment

First of all, install tox utility. It’s likely to be in your distribution repositories under name of python-tox. Alternatively, you can install it from PyPI.

Next checkout and create environments:

git clone
cd ironic-inspector

Repeat tox command each time you need to run tests. If you don’t have Python interpreter of one of supported versions (currently 3.6 and 3.7), use -e flag to select only some environments, e.g.

tox -e py36


This command also runs tests for database migrations. By default the sqlite backend is used. For testing with mysql or postgresql, you need to set up a db named ‘openstack_citest’ with user ‘openstack_citest’ and password ‘openstack_citest’ on localhost. Use the script tools/ to set the database up the same way as done in the OpenStack CI environment.


Users of Fedora <= 23 will need to run “sudo dnf –releasever=24 update python-virtualenv” to run unit tests

To run the functional tests, use:

tox -e func

Once you have added new state or transition into inspection state machine, you should regenerate State machine diagram with:

tox -e genstates

Run the service with:

.tox/py36/bin/ironic-inspector --config-file example.conf

Of course you may have to modify example.conf to match your OpenStack environment. See the install guide for information on generating or downloading an example configuration file.

You can develop and test ironic-inspector using DevStack - see Deploying Ironic Inspector with DevStack for the current status.

Deploying Ironic Inspector with DevStack

DevStack provides a way to quickly build a full OpenStack development environment with requested components. There is a plugin for installing ironic-inspector in DevStack. Installing ironic-inspector requires a machine running Ubuntu 14.04 (or later) or Fedora 23 (or later). Make sure this machine is fully up to date and has the latest packages installed before beginning this process.

Download DevStack:

git clone
cd devstack

Create local.conf file with minimal settings required to enable both the ironic and the ironic-inspector. You can start with the Example local.conf and extend it as needed.

Example local.conf

# Credentials

# Enable Ironic plugin
enable_plugin ironic
enable_plugin ironic-inspector

# Disable nova novnc service, ironic does not support it anyway.
disable_service n-novnc

# Enable Swift for the direct deploy interface.
enable_service s-proxy
enable_service s-object
enable_service s-container
enable_service s-account

# Disable Horizon
disable_service horizon

# Disable Cinder
disable_service cinder c-sch c-api c-vol

# Swift temp URL's are required for the direct deploy interface

# Create 3 virtual machines to pose as Ironic's baremetal nodes.

# Enable additional hardware types, if needed.
# Don't forget that many hardware types require enabling of additional
# interfaces, most often power and management:
# The 'ipmi' hardware type's default deploy interface is 'iscsi'.
# This would change the default to 'direct':

# Enable inspection via ironic-inspector
# Make it the default for all hardware types:

# Change this to alter the default driver for nodes created by devstack.
# This driver should be in the enabled list above.

# The parameters below represent the minimum possible values to create
# functional nodes.

# Size of the ephemeral partition in GB. Use 0 for no ephemeral partition.

# To build your own IPA ramdisk from source, set this to True

# By default, DevStack creates a network for instances.
# If this overlaps with the hosts network, you may adjust with the
# following.

# Log all output to files


  • Set IRONIC_INSPECTOR_BUILD_RAMDISK to True if you want to build ramdisk. Default value is False and ramdisk will be downloaded instead of building.

  • 1024 MiB of RAM is a minimum required for the default build of IPA based on CoreOS. If you plan to use another operating system and build IPA with diskimage-builder 2048 MiB is recommended.

  • Network configuration is pretty sensitive, better not to touch it without deep understanding.

  • This configuration disables horizon, heat, cinder and tempest, adjust it if you need these services.

Start the install:



After installation is complete, you can source openrc in your shell, and then use the OpenStack CLI to manage your DevStack:

source openrc admin demo

Show DevStack screens:

screen -x stack

To exit screen, hit CTRL-a d.

List baremetal nodes:

baremetal node list

Bring the node to manageable state:

baremetal node manage <NodeID>

Inspect the node:

baremetal node inspect <NodeID>


The deploy driver used must support the inspect interface. See also the Ironic Python Agent.

A node can also be inspected using the following command. However, this will not affect the provision state of the node:

baremetal introspection start <NodeID>

Check inspection status:

baremetal introspection status <NodeID>

Optionally, get the inspection data:

baremetal introspection data save <NodeID>

Writing a Plugin

  • ironic-inspector allows you to hook code into the data processing chain after introspection. Inherit ProcessingHook class defined in ironic_inspector.plugins.base module and overwrite any or both of the following methods:


    called before any data processing, providing the raw data. Each plugin in the chain can modify the data, so order in which plugins are loaded matters here. Returns nothing.


    called after node is found and ports are created, but before data is updated on a node. Please refer to the docstring for details and examples.

    You can optionally define the following attribute:


    a list of entry point names of the hooks this hook depends on. These hooks are expected to be enabled before the current hook.

    Make your plugin a setuptools entry point under ironic_inspector.hooks.processing namespace and enable it in the configuration file (processing.processing_hooks option).

  • ironic-inspector allows plugins to override the action when node is not found in node cache. Write a callable with the following signature:


    called when node is not found in cache, providing the processed data. Should return a NodeInfo class instance.

    Make your plugin a setuptools entry point under ironic_inspector.hooks.node_not_found namespace and enable it in the configuration file (processing.node_not_found_hook option).

  • ironic-inspector allows more condition types to be added for Introspection Rules. Inherit RuleConditionPlugin class defined in ironic_inspector.plugins.base module and overwrite at least the following method:


    called to check that condition holds for a given field. Field value is provided as field argument, params is a dictionary defined at the time of condition creation. Returns boolean value.

    The following methods and attributes may also be overridden:


    called to validate parameters provided during condition creating. Default implementation requires keys listed in REQUIRED_PARAMS (and only them).


    contains set of required parameters used in the default implementation of validate method, defaults to value parameter.


    if it’s set to True, missing fields will be passed as None values instead of failing the condition. Defaults to False.

    Make your plugin a setuptools entry point under ironic_inspector.rules.conditions namespace.

  • ironic-inspector allows more action types to be added for Introspection Rules. Inherit RuleActionPlugin class defined in ironic_inspector.plugins.base module and overwrite at least the following method:


    called to apply the action.

    The following methods and attributes may also be overridden:


    called to validate parameters provided during actions creating. Default implementation requires keys listed in REQUIRED_PARAMS (and only them).


    contains set of required parameters used in the default implementation of validate method, defaults to no parameters.

    Make your plugin a setuptools entry point under ironic_inspector.rules.conditions namespace.


** argument is needed so that we can add optional arguments without breaking out-of-tree plugins. Please make sure to include and ignore it.

Making changes to the database

In order to make a change to the ironic-inspector database you must update the database models found in ironic_inspector.db package and then create a migration to reflect that change.

There are two ways to create a migration which are described below, both of these generate a new migration file. In this file there is only one function:

  • upgrade - The function to run when

    ironic-inspector-dbsync upgrade is run, and should be populated with code to bring the database up to its new state from the state it was in after the last migration.

For further information on creating a migration, refer to Create a Migration Script from the alembic documentation.


This is the simplest way to create a migration. Alembic will compare the models to an up to date database, and then attempt to write a migration based on the differences. This should generate correct migrations in most cases however there are some cases when it can not detect some changes and may require manual modification, see What does Autogenerate Detect (and what does it not detect?) from the alembic documentation.

ironic-inspector-dbsync upgrade
ironic-inspector-dbsync revision -m "A short description" --autogenerate


This will generate an empty migration file, with the correct revision information already included. However the upgrade function is left empty and must be manually populated in order to perform the correct actions on the database:

ironic-inspector-dbsync revision -m "A short description"

Implementing PXE Filter Drivers


inspector in-band introspection PXE-boots the Ironic Python Agent “live” image, to inspect the baremetal server. ironic also PXE-boots IPA to perform tasks on a node, such as deploying an image. ironic uses neutron to provide DHCP, however neutron does not provide DHCP for unknown MAC addresses so inspector has to use its own DHCP/TFTP stack for discovery and inspection.

When ironic and inspector are operating in the same L2 network, there is a potential for the two DHCPs to race, which could result in a node being deployed by ironic being PXE booted by inspector.

To prevent DHCP races between the inspector DHCP and ironic DHCP, inspector has to be able to filter which nodes can get a DHCP lease from the inspector DHCP server. These filters can then be used to prevent node’s enrolled in ironic inventory from being PXE-booted unless they are explicitly moved into the inspected state.

Filter Interface

The contract between inspector and a PXE filter driver is described in the FilterDriver interface. The methods a driver has to implement are:

  • init_filter() called on the service start to initialize internal driver state

  • sync() called both periodically and when a node starts or finishes introspection to allow or deny its ports MAC addresses in the driver

  • tear_down_filter() called on service exit to reset the internal driver state

The driver-specific configuration is suggested to be parsed during instantiation. There’s also a convenience generic interface implementation BaseFilter that provides base locking and initialization implementation. If required, a driver can opt-out from the periodic synchronization by overriding the get_periodic_sync_task().

Python API

Ironic Inspector CI

It’s important to understand the role of each job in the CI. To facilitate that, we have created the documentation below.