undercloud: switch to the "direct" deploy interface by default

Instead of serving images via slow and somewhat unreliable iSCSI protocol,
this deploy method makes IPA download them from the undercloud Swift.

Change-Id: Ic569358b781337ec6ba8ba802ada1f940917bd61
Implements: blueprint ironic-direct-deploy

environments/undercloud.yaml

@@ -40,6 +40,7 @@ parameter_defaults:
   HeatMaxJsonBodySize: 2097152
   IronicCleaningDiskErase: 'metadata'
   IronicCorsAllowedOrigin: '*'
+  IronicDefaultDeployInterface: 'direct'
   IronicDefaultInspectInterface: 'inspector'
   IronicDefaultResourceClass: 'baremetal'
   IronicEnabledHardwareTypes: ['ipmi', 'redfish', 'idrac', 'ilo']

puppet/services/ironic-conductor.yaml

@@ -67,6 +67,11 @@ parameters:
                  images). Set to 'netboot' to make the instances boot from
                  controllers using PXE/iPXE.
     type: string
+  IronicDefaultDeployInterface:
+    default: ''
+    description: Deploy interface implementation to use by default. Leave empty to
+                 use the hardware type default.
+    type: string
   IronicDefaultInspectInterface:
     default: ''
     description: Inspect interface implementation to use by default. Leave empty to
@@ -214,6 +219,7 @@ resources:
       IronicDebug: {get_param: IronicDebug}
 
 conditions:
+  default_deploy_interface_unset: {equals : [{get_param: IronicDefaultDeployInterface}, '']}
   default_inspect_interface_unset: {equals : [{get_param: IronicDefaultInspectInterface}, '']}
   service_debug:
     or:
@@ -231,6 +237,11 @@ outputs:
       config_settings:
         map_merge:
           - get_attr: [IronicBase, role_data, config_settings]
+          -
+            if:
+            - default_deploy_interface_unset
+            - {}
+            - ironic::drivers::interfaces::default_deploy_interface: {get_param: IronicDefaultDeployInterface}
           -
             if:
             - default_inspect_interface_unset

releasenotes/notes/direct-deploy-by-default-bc78a63f0a0c6e15.yaml

@@ -0,0 +1,12 @@
+---
+upgrade:
+  - |
+    Ironic in the containerized undercloud now uses the ``direct`` deploy
+    interface by default for better performance and scalability. See
+    `the direct deploy documentation
+    <https://docs.openstack.org/ironic/latest/admin/interfaces/deploy.html#direct-deploy>`_
+    for details.
+
+    If undesired, this change can be reverted per node by setting the node's
+    ``deploy_interface`` field to ``iscsi`` or globally by changing the new
+    ``IronicDefaultDeployInterface`` to empty string.