config.yaml

---
- copies:
  cinder-blah: 0
  neutron-agents: 6
- cidr: 10.0.0.0/24
- vip: 10.0.0.250
- infra_hosts:
  - infra1:
    ip: 10.0.0.1
    - copies:
      neutron-agents: 0
  - infra2:
    ip: 10.0.0.2
  - infra3:
    ip: 10.0.0.3
- compute_hosts:
  - compute1:
    ip: 10.0.0.4
  - compute2:
    ip: 10.0.0.5
  - compute3:
    ip: 10.0.0.6
- storage_hosts:
  - cinder1:
    ip: 10.0.0.10
  - swift1:
    ip: 10.0.0.20

hostmap.json

{
  // User specified
  "all": {
    "vars": {
      "vip_address": "10.0.0.250"
    }
  },
  "infra_hosts": {
    "hosts": ["infra1", "infra2", "infra3"]
  },
  "compute_hosts": {
    "hosts": ["compute1", "compute2"]
  },
  "storage_hosts": {
    "hosts": ["cinder1", "swift1"]
  },
  // Dynamically generated
  "hosts": {
    "children": ["infra_hosts", "compute_hosts"]
  },
  "containers": {
    "children": ["infra_containers", "compute_containers"]
  },
  "infra_containers": {
    "children": ["glance-api"]
  },
  "glance-api": {
    "hosts": ["infra1-glance-api-1234", "infra2-glance-api-5678"]
  },
  "compute_containers": {
    "children": ["nova-all"]
  },
  "nova-all": {
    "children": ["nova-compute", "nova-api-os-compute"]
  },
  "nova-compute": {
    "hosts": ["compute1-nova-compute-1234", "compute2-nova-compute-5678"]
  },
  "neutron-all": {
    "children": ["neutron-linuxbridge-agent", "neutron-agents"]
  },
  "neutron-linuxbridge-agent": {
    "hosts": [
      "compute1-nova-compute-1234",
      "compute2-nova-compute-5678",
      "infra1-neutron-agent-8972"
    ]
  },
  "_meta": {
    "hostvars": {
      // User specified
      "infra1": {
        "ansible_ssh_host": "10.0.0.1"
      },
      "infra2": {
        "ansible_ssh_host": "10.0.0.2"
      },
      "infra3": {
        "ansible_ssh_host": "10.0.0.3"
      },
      "compute1": {
        "ansible_ssh_host": "10.0.0.4"
      },
      "compute2": {
        "ansible_ssh_host": "10.0.0.5"
      },
      // Dynamically generated
      "nova-compute.1234": {
        "ansible_ssh_host": "1.2.3.4",
        "container_name": "nova-compute"
      }
    }
  }
}

infra.yaml

---
- name: Build Infra Containers
  host: infra_hosts
  tasks:
    - name: Build Containers
      something: blah {{hostvars[item].ansible_ssh_host}}
      with_items: group["infra_containers"]

- name: Build Compute Containers
  host: compute_hosts
  tasks:
    - name: Build Containers
      something: blah {{hostvars[item].ansible_ssh_host}}
      with_items: group["compute_containers"]

- name: Provision Containers Common
  host: containers
  roles:
    - common_container

- name: Provision Keystone
  host: keystone-all
  roles:
    - keystone_common
    - keystone_api

- name: Provision Keystone Setup
  host: keystone-all[0]
  roles:
    - keystone_setup

- name: Provision Nova
  host: nova-all
  roles:
    - nova_common

- name: Provision Nova Setup
  host: nova-all[0]
  roles:
    - nova_setup
    - nova_api