adds validation to kubernetes config form (#19097)

ui/lib/kubernetes/addon/components/page/configure.hbs

@@ -73,7 +73,7 @@
 
 <hr class="has-background-gray-200 has-top-margin-l" />
 
-<div class="has-top-margin-s has-bottom-margin-s">
+<div class="has-top-margin-s has-bottom-margin-s is-flex">
   <button
     data-test-config-save
     class="button is-primary"
@@ -92,6 +92,9 @@
   >
     Back
   </button>
+  {{#if this.alert}}
+    <AlertInline @type="danger" @paddingTop={{true}} @message={{this.alert}} @mimicRefresh={{true}} data-test-alert />
+  {{/if}}
 </div>
 
 {{#if this.showConfirm}}

ui/lib/kubernetes/addon/components/page/configure.js

@@ -18,6 +18,7 @@ export default class ConfigurePageComponent extends Component {
 
   @tracked inferredState;
   @tracked modelValidations;
+  @tracked alert;
   @tracked error;
   @tracked showConfirm;
 
@@ -64,6 +65,14 @@ export default class ConfigurePageComponent extends Component {
       return;
     }
     this.showConfirm = false;
+
+    const { isValid, state, invalidFormMessage } = yield this.args.model.validate();
+    if (!isValid) {
+      this.modelValidations = state;
+      this.alert = invalidFormMessage;
+      return;
+    }
+
     try {
       yield this.args.model.save();
       this.leave('configuration');