added azure_cloud parameter to Azure's cloud_config (#6321)

roles/kubernetes/node/defaults/main.yml

@@ -143,3 +143,5 @@ azure_exclude_master_from_standard_lb: true
 azure_disable_outbound_snat: false
 # use instance metadata service where possible
 azure_use_instance_metadata: true
+# use specific Azure API endpoints
+azure_cloud: AzurePublicCloud

roles/kubernetes/node/tasks/cloud-credentials/azure-credential-check.yml

@@ -75,3 +75,8 @@
   fail:
     msg: "azure_vmtype is missing. Supported values are 'standard' or 'vmss'"
   when: azure_vmtype is not defined or not azure_vmtype
+
+- name: check azure_cloud value
+  fail:
+    msg: "azure_cloud has an invalid value '{{ azure_cloud }}'. Supported values are 'AzureChinaCloud', 'AzureGermanCloud', 'AzurePublicCloud', 'AzureUSGovernmentCloud'."
+  when: azure_cloud not in ["AzureChinaCloud", "AzureGermanCloud", "AzurePublicCloud", "AzureUSGovernmentCloud"]

roles/kubernetes/node/templates/cloud-configs/azure-cloud-config.j2

@@ -1,4 +1,5 @@
 {
+  "cloud": "{{ azure_cloud }}"
   "tenantId": "{{ azure_tenant_id }}",
   "subscriptionId": "{{ azure_subscription_id }}",
   "aadClientId": "{{ azure_aad_client_id }}",