From ba0340e64c90af1be88ff25d36a7066c25c7c781 Mon Sep 17 00:00:00 2001
From: Milan Fencik <milan.fencik@rackspace.co.uk>
Date: Mon, 10 Nov 2025 16:03:48 +0000
Subject: [PATCH] add a noop deploy interface patch

For infrastructure and any other devices that we do not
want Ironic to manage, yet they need to be present in
the Ironic inventory, we're using fake drivers when
enrolling them. This is causing a problem for conductor.
This patch will enable us to use noop deploy-interface
with driver set to manual-management, which will save
resources lookup and management that Ironic is doing.
---
 components/ironic/values.yaml                 |  2 +-
 .../ironic_understack/noop_deploy.py          | 82 +++++++++++++++++++
 python/ironic-understack/pyproject.toml       |  3 +
 3 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 python/ironic-understack/ironic_understack/noop_deploy.py

diff --git a/components/ironic/values.yaml b/components/ironic/values.yaml
index a6e3d9751..e0c6c52ae 100644
--- a/components/ironic/values.yaml
+++ b/components/ironic/values.yaml
@@ -51,7 +51,7 @@ conf:
       default_deploy_interface: direct
       enabled_bios_interfaces: no-bios,redfish,idrac-redfish,ilo
       enabled_boot_interfaces: http-ipxe,ipxe,redfish-virtual-media,redfish-https,idrac-redfish-virtual-media,ilo-virtual-media,ilo-uefi-https,ilo-ipxe
-      enabled_deploy_interfaces: direct,ramdisk
+      enabled_deploy_interfaces: direct,ramdisk,noop
       enabled_firmware_interfaces: redfish,no-firmware
       enabled_hardware_types: redfish,idrac,ilo5,ilo
       enabled_inspect_interfaces: redfish,agent,idrac-redfish,ilo
diff --git a/python/ironic-understack/ironic_understack/noop_deploy.py b/python/ironic-understack/ironic_understack/noop_deploy.py
new file mode 100644
index 000000000..1d9724aa4
--- /dev/null
+++ b/python/ironic-understack/ironic_understack/noop_deploy.py
@@ -0,0 +1,82 @@
+from ironic.common import states
+from ironic.drivers import base
+
+
+class NoDeploy(base.DeployInterface):
+    """Deploy interface that does nothing and succeeds.
+
+    This interface allows Ironic to manage bare metal nodes for inventory,
+    lifecycle tracking, and resource management without performing actual OS
+    deployment operations.
+
+    All methods succeed immediately without performing actual operations.
+    Node state transitions occur as expected by Ironic's state machine.
+    """
+
+    def get_properties(self):
+        """Return the properties of the interface.
+
+        Returns:
+            dict: Empty dictionary as no configuration is required.
+        """
+        return {}
+
+    def validate(self, task):
+        """Validate the driver-specific Node deployment info.
+
+        This method intentionally accepts any node configuration for noop deploy.
+
+        Args:
+            task: A TaskManager instance containing the node to act on.
+        """
+        pass
+
+    @base.deploy_step(priority=100)
+    def deploy(self, task):
+        """Perform a deployment to a node.
+
+        This method returns None to indicate synchronous success without
+        performing any actual deployment operations.
+
+        Args:
+            task: A TaskManager instance containing the node to act on.
+
+        Returns:
+            None: Indicates synchronous completion.
+        """
+        return None
+
+    def tear_down(self, task):
+        """Tear down a previous deployment on the task's node.
+
+        Args:
+            task: A TaskManager instance containing the node to act on.
+
+        Returns:
+            states.DELETED: Indicates the node is torn down.
+        """
+        return states.DELETED
+
+    def prepare(self, task):
+        """Prepare the deployment environment for the task's node.
+
+        Args:
+            task: A TaskManager instance containing the node to act on.
+        """
+        pass
+
+    def clean_up(self, task):
+        """Clean up the deployment environment for the task's node.
+
+        Args:
+            task: A TaskManager instance containing the node to act on.
+        """
+        pass
+
+    def take_over(self, task):
+        """Take over management of this task's node from a dead conductor.
+
+        Args:
+            task: A TaskManager instance containing the node to act on.
+        """
+        pass
diff --git a/python/ironic-understack/pyproject.toml b/python/ironic-understack/pyproject.toml
index 74bda2a10..6d77166c7 100644
--- a/python/ironic-understack/pyproject.toml
+++ b/python/ironic-understack/pyproject.toml
@@ -27,6 +27,9 @@ chassis_model = "ironic_understack.inspect_hook_chassis_model:InspectHookChassis
 redfish-understack = "ironic_understack.redfish_inspect_understack:UnderstackRedfishInspect"
 idrac-redfish-understack = "ironic_understack.redfish_inspect_understack:UnderstackDracRedfishInspect"
 
+[project.entry-points."ironic.hardware.interfaces.deploy"]
+noop = "ironic_understack.noop_deploy:NoDeploy"
+
 [dependency-groups]
 test = [
     "pytest>=9.0.1,<10",