Generating the Inventory¶

Executing the dynamic_inventory.py script manually¶

When running an Ansible command (such as ansible, ansible-playbook or openstack-ansible) Ansible automatically executes the dynamic_inventory.py script and use its output as inventory.

Run the following command:

# from the root folder of cloned OpenStack-Ansible repository
inventory/dynamic_inventory.py --config /etc/openstack_deploy/

This invocation is useful when testing changes to the dynamic inventory script.

Inputs¶

The dynamic_inventory.py takes the --config argument for the directory holding configuration from which to create the inventory. If not specified, the default is /etc/openstack_deploy/.

In addition to this argument, the base environment skeleton is provided in the inventory/env.d directory of the OpenStack-Ansible codebase.

Should an env.d directory be found in the directory specified by --config, its contents will be added to the base environment, overriding any previous contents in the event of conflicts.

The following file must be present in the configuration directory:

• openstack_user_config.yml

Additionally, the configuration or environment could be spread between two additional sub-directories:

• conf.d
• env.d (for environment customization)

The dynamic inventory script does the following:

• Generates the names of each container that runs a service
• Creates container and IP address mappings
• Assigns containers to physical hosts

As an example, consider the following excerpt from openstack_user_config.yml:

identity_hosts:
  infra01:
    ip: 10.0.0.10
  infra02:
    ip: 10.0.0.11
  infra03:
    ip: 10.0.0.12

The identity_hosts dictionary defines an Ansible inventory group named identity_hosts containing the three infra hosts. The configuration file inventory/env.d/keystone.yml defines additional Ansible inventory groups for the containers that are deployed onto the three hosts named with the prefix infra.

Note that any services marked with is_metal: true will run on the allocated physical host and not in a container. For an example of is_metal: true being used refer to inventory/env.d/cinder.yml in the container_skel section.

For more details, see Configuring the inventory.

Outputs¶

Once executed, the script will output an openstack_inventory.json file into the directory specified with the --config argument. This is used as the source of truth for repeated runs.

The same JSON structure is printed to stdout, which is consumed by Ansible as the inventory for the playbooks.

Checking inventory configuration for errors¶

Using the --check flag when running dynamic_inventory.py will run the inventory build process and look for known errors, but not write any files to disk.

If any groups defined in the openstack_user_config.yml or conf.d files are not found in the environment, a warning will be raised.

This check does not do YAML syntax validation, though it will fail if there are unparseable errors.

Writing debug logs¶

The --debug/-d parameter allows writing of a detailed log file for debugging the inventory script’s behavior. The output is written to inventory.log in the current working directory.

The inventory.log file is appended to, not overwritten.

Like --check, this flag is not invoked when running from ansible.