[release-2.27] Add manual option to the external_cloud_provider variable (#11884)

* Add `manual` option in the `external_cloud_provider` value

Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>

* Update external cloud provider description in roles & sample inventory

Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>

---------

Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>
Co-authored-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>

roles/kubernetes/preinstall/tasks/0040-verify-settings.yml

@@ -185,7 +185,7 @@
 
 - name: Check external_cloud_provider value
   assert:
-    that: external_cloud_provider in ['hcloud', 'huaweicloud', 'oci', 'openstack', 'vsphere']
+    that: external_cloud_provider in ['hcloud', 'huaweicloud', 'oci', 'openstack', 'vsphere', 'manual']
   when:
     - cloud_provider == 'external'
     - not ignore_assert_errors

roles/kubespray-defaults/defaults/main/main.yml

@@ -285,7 +285,8 @@ kubelet_shutdown_grace_period_critical_pods: 20s
 cloud_provider: ""
 # External Cloud Controller Manager (Formerly known as cloud provider)
 # cloud_provider must be "external", otherwise this setting is invalid.
-# Supported external cloud controllers are: 'openstack', 'vsphere', 'oci', 'huaweicloud' and 'hcloud'
+# Supported external cloud controllers are: 'openstack', 'vsphere', 'oci', 'huaweicloud', 'hcloud' and 'manual'
+# 'manual' does not install the cloud controller manager used by Kubespray.
 # If you fill in a value other than the above, the check will fail.
 external_cloud_provider: ""