openstack-ansible/doc/source/reference/inventory/configure-inventory.rst

Configuring the inventory

In this chapter, you can find the information on how to configure the openstack-ansible dynamic inventory to your needs.

Introduction

Common OpenStack services and their configuration are defined by OpenStack-Ansible in the /etc/openstack_deploy/openstack_user_config.yml settings file.

Additional services should be defined with a YAML file in /etc/openstack_deploy/conf.d, in order to manage file size.

The /etc/openstack_deploy/env.d directory sources all YAML files into the deployed environment, allowing a deployer to define additional group mappings. This directory is used to extend the environment skeleton, or modify the defaults defined in the inventory/env.d directory.

To understand how the dynamic inventory works, see inventory-in-depth.

Warning

Never edit or delete the file /etc/openstack_deploy/openstack_inventory.json. This can lead to problems with the inventory: existng hosts and containers will be unmanaged and new ones will be generated instead, breaking your existing deployment.

Configuration constraints

Group memberships

When adding groups, keep the following in mind:

• A group can contain hosts
• A group can contain child groups

However, groups cannot contain child groups and hosts.

The lxc_hosts Group

When the dynamic inventory script creates a container name, the host on which the container resides is added to the lxc_hosts inventory group.

Using this name for a group in the configuration will result in a runtime error.

Deploying directly on hosts

To deploy a component directly on the host instead of within a container, set the is_metal property to true for the container group in the container_skel section in the appropriate file.

The use of container_vars and mapping from container groups to host groups is the same for a service deployed directly onto the host.

You can also use the no_containers option to specify a host that will have all services deployed on metal inside of it.

Note

The cinder-volume component is deployed directly on the host by default. See the env.d/cinder.yml file for this example.

Example: Running all controllers on metal

For example, if you'd like to run all your controllers on metal, you would have the following inside your openstack_user_config.yml.

infra_hosts:
  infra1:
    ip: 172.39.123.11
    no_containers: true
  infra2:
    ip: 172.39.123.12
    no_containers: true
  infra3:
    ip: 172.39.123.13
    no_containers: true

Example: Running galera on dedicated hosts

For example, to run Galera directly on dedicated hosts, you would perform the following steps:

1. Modify the container_skel section of the env.d/galera.yml file. For example:

   container_skel:
     galera_container:
       belongs_to:
         - db_containers
       contains:
         - galera
       properties:
         is_metal: true

   Note

   To deploy within containers on these dedicated hosts, omit the is_metal: true property.

2. Assign the db_containers container group (from the preceding step) to a host group by providing a physical_skel section for the host group in a new or existing file, such as env.d/galera.yml. For example:

   physical_skel:
     db_containers:
       belongs_to:
         - all_containers
     db_hosts:
       belongs_to:
         - hosts

3. Define the host group (db_hosts) in a conf.d/ file (such as galera.yml). For example:

   db_hosts:
     db-host1:
       ip: 172.39.123.11
     db-host2:
       ip: 172.39.123.12
     db-host3:
       ip: 172.39.123.13

   Note

   Each of the custom group names in this example (db_containers and db_hosts) are arbitrary. Choose your own group names, but ensure the references are consistent among all relevant files.

Deploying 0 (or more than one) of component type per host

When OpenStack-Ansible generates its dynamic inventory, the affinity setting determines how many containers of a similar type are deployed on a single physical host.

Using shared-infra_hosts as an example, consider this openstack_user_config.yml configuration:

shared-infra_hosts:
  infra1:
    ip: 172.29.236.101
  infra2:
    ip: 172.29.236.102
  infra3:
    ip: 172.29.236.103

Three hosts are assigned to the shared-infra_hosts group, OpenStack-Ansible ensures that each host runs a single database container, a single Memcached container, and a single RabbitMQ container. Each host has an affinity of 1 by default, which means that each host runs one of each container type.

If you are deploying a stand-alone Object Storage (swift) environment, you can skip the deployment of RabbitMQ. If you use this configuration, your openstack_user_config.yml file would look as follows:

shared-infra_hosts:
  infra1:
    affinity:
      rabbit_mq_container: 0
    ip: 172.29.236.101
  infra2:
    affinity:
      rabbit_mq_container: 0
    ip: 172.29.236.102
  infra3:
    affinity:
      rabbit_mq_container: 0
    ip: 172.29.236.103

This configuration deploys a Memcached container and a database container on each host, but no RabbitMQ containers.

Omit a service or component from the deployment

To omit a component from a deployment, you can use one of several options:

• Remove the physical_skel link between the container group and the host group by deleting the related file located in the env.d/ directory.
• Do not run the playbook that installs the component. Unless you specify the component to run directly on a host by using the is_metal property, a container is created for this component.
• Adjust the affinity to 0 for the host group. Similar to the second option listed here, Unless you specify the component to run directly on a host by using the is_metal property, a container is created for this component.