Refactor: simpify external_cloud_provider is defined

For this change, `external_cloud_provider` set default value to empty
string.

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

roles/kubernetes-apps/external_cloud_controller/meta/main.yml

@@ -3,7 +3,6 @@ dependencies:
   - role: kubernetes-apps/external_cloud_controller/openstack
     when:
       - cloud_provider == "external"
-      - external_cloud_provider is defined
       - external_cloud_provider == "openstack"
       - inventory_hostname == groups['kube_control_plane'][0]
     tags:
@@ -12,7 +11,6 @@ dependencies:
   - role: kubernetes-apps/external_cloud_controller/vsphere
     when:
       - cloud_provider == "external"
-      - external_cloud_provider is defined
       - external_cloud_provider == "vsphere"
       - inventory_hostname == groups['kube_control_plane'][0]
     tags:
@@ -21,7 +19,6 @@ dependencies:
   - role: kubernetes-apps/external_cloud_controller/hcloud
     when:
       - cloud_provider == "external"
-      - external_cloud_provider is defined
       - external_cloud_provider == "hcloud"
       - inventory_hostname == groups['kube_control_plane'][0]
     tags:
@@ -30,7 +27,6 @@ dependencies:
   - role: kubernetes-apps/external_cloud_controller/huaweicloud
     when:
       - cloud_provider == "external"
-      - external_cloud_provider is defined
       - external_cloud_provider == "huaweicloud"
       - inventory_hostname == groups['kube_control_plane'][0]
     tags:
@@ -39,7 +35,6 @@ dependencies:
   - role: kubernetes-apps/external_cloud_controller/oci
     when:
       - cloud_provider == "external"
-      - external_cloud_provider is defined
       - external_cloud_provider == "oci"
       - inventory_hostname == groups['kube_control_plane'][0]
     tags:

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

@@ -174,6 +174,16 @@
     - cloud-provider
     - facts
 
+- name: Check external_cloud_provider value
+  assert:
+    that: external_cloud_provider in ['hcloud', 'huaweicloud', 'oci', 'openstack', 'vsphere']
+  when:
+    - cloud_provider == 'external'
+    - not ignore_assert_errors
+  tags:
+    - cloud-provider
+    - facts
+
 - name: "Check that kube_service_addresses is a network range"
   assert:
     that:

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

@@ -274,6 +274,12 @@ kubelet_shutdown_grace_period_critical_pods: 20s
 # Cloud Provider
 # This variable can only be set to "external" or empty string, otherwise the check will fail.
 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'
+# If you fill in a value other than the above, the check will fail.
+external_cloud_provider: ""
+
 # Whether to deploy the container engine
 deploy_container_engine: "{{ 'k8s_cluster' in group_names or etcd_deployment_type == 'docker' }}"