diff --git a/ansible/action_plugins/tenks_schedule.py b/ansible/action_plugins/tenks_schedule.py
index 275f8ba..9e2035e 100644
--- a/ansible/action_plugins/tenks_schedule.py
+++ b/ansible/action_plugins/tenks_schedule.py
@@ -31,8 +31,7 @@ class ActionModule(ActionBase):
         The following task vars are accepted:
             :hypervisor_vars: A dict of hostvars for each hypervisor, keyed
                               by hypervisor hostname. Required.
-            :specs: A dict mapping node type names to the number of nodes
-                    required of that type. Required.
+            :specs: A list of node specifications to be instantiated. Required.
             :node_types: A dict mapping node type names to a dict of properties
                          of that type.
             :node_name_prefix: A string with which to prefix all sequential
@@ -48,7 +47,15 @@ class ActionModule(ActionBase):
 
         nodes = []
         idx = 0
-        for typ, cnt in six.iteritems(task_vars['specs']):
+        for spec in task_vars['specs']:
+            try:
+                typ = spec['type']
+                cnt = spec['count']
+            except KeyError:
+                e = ("All specs must contain a `type` and a `count`. "
+                     "Offending spec: %s" % spec)
+                raise AnsibleActionFail(to_text(e))
+
             for _ in six.moves.range(cnt):
                 node = deepcopy(task_vars['node_types'][typ])
                 # Set the type, for future reference.
diff --git a/ansible/host_vars/localhost b/ansible/host_vars/localhost
index a590603..7ea5242 100644
--- a/ansible/host_vars/localhost
+++ b/ansible/host_vars/localhost
@@ -1,7 +1,4 @@
 ---
-allocations_file_path: >-
-    {{ '/'.join([(playbook_dir | dirname), 'allocations.yml']) }}
-
 # node_types is a dict that defines different sets of node specifications,
 # keyed by a 'node type name' to associate with each set of specifications. An
 # example of the format of this variable is below:
@@ -21,19 +18,82 @@ allocations_file_path: >-
 #     # vars.
 #     physical_networks:
 #       - physnet1
+#     # The BMC type for nodes of this type. If not set, `default_bmc_type`
+#     # will be used.
+#     bmc_type: ipmi
 node_types: {}
 
-# specs is a dict that maps different node type names (define in `node_types`
-# above) to the number of nodes of that type that are to be created. Only node
-# types which you want to create nodes from need be keyed here. For example:
+# specs is a list of configurations of nodes to be created. Each configuration
+# can specify the number of nodes to be created, the type (from `node_types`)
+# of these nodes, and optionally configuration for the Ironic nodes to be
+# enroled from these nodes. If `ironic_config` is not set, Ironic enrolment
+# will be skipped for that spec.
+# For example:
 #
 # specs:
-#   # Create four nodes with the specifications defined in `node_types` by
-#   # 'type0'.
-#   type0: 4
-specs: {}
+#     # Required.
+#   - type: type0
+#     # Required.
+#     count: 4
+#     # Optional.
+#     ironic_config:
+#       # Required.
+#       resource_class: my_rc
+#       # Optional - defaults to [].
+#       traits: []
+#       # The following variables are all optional; if not set, a default will
+#       # be inferred from the `bmc_type` specified by the node type `type`.
+#       hardware_type: ipmi
+#       boot_interface: pxe
+#       deploy_interface: iscsi
+#       management_interface: ipmitool
+#       power_interface: ipmitool
+specs: []
+
+# nova_flavors is a list of Nova flavors to be created. Each flavor must
+# specify the resource class it is associated with. This resource class must
+# be referenced in `specs`.
+#
+# For example:
+#
+# nova_flavors:
+#     # Required.
+#   - resource_class: my_rc
+#     # Defaults to `resource_class`.
+#     name: my_flavor
+#     # Optional, defaults to [].
+#     required_traits: []
+#     # Optional, defaults to [].
+#     forbidden_traits: []
+nova_flavors: []
 
 # The Glance UUID of the image to use for the deployment kernel.
 deploy_kernel_uuid:
 # The Glance UUID of the image to use for the deployment ramdisk.
 deploy_ramdisk_uuid:
+
+
+allocations_file_path: >-
+    {{ '/'.join([(playbook_dir | dirname), 'allocations.yml']) }}
+
+# The default BMC type of a node. Can be overridden per-node.
+default_bmc_type: ipmi
+# Maps BMC types to a dict containing default values for Ironic node
+# interfaces, a hardware type, and a BMC emulation tool to use. Any of these
+# values can be overridden per-node.
+default_bmc_info:
+  ipmi:
+    bmc_emulator: virtualbmc
+    hardware_type: ipmi
+    boot_interface: pxe
+    deploy_interface: iscsi
+    management_interface: ipmitool
+    power_interface: ipmitool
+  # NOTE(w-miller): Redfish is not currently fully supported by Tenks.
+  redfish:
+    bmc_emulator: sushy-tools
+    hardware_type: redfish
+    boot_interface: pxe
+    deploy_interface: iscsi
+    management_interface: redfish
+    power_interface: redfish
diff --git a/ansible/schedule.yml b/ansible/schedule.yml
index a80647f..e3acbcb 100644
--- a/ansible/schedule.yml
+++ b/ansible/schedule.yml
@@ -7,9 +7,11 @@
   tasks:
     - name: Check that all specified node types exist
       fail:
-        msg: The non-existent node type {{ item }} was specified in 'specs'.
-      when: item not in node_types
-      loop: "{{ specs.keys() }}"
+        msg: >
+          The non-existent node type {{ item.type }} was specified in
+          'specs'.
+      when: item.type not in node_types
+      loop: "{{ specs }}"
 
     # Creates a dict mapping each hypervisor's hostname to its hostvars, to be
     # used during scheduling.