feat(kubernetes): fix annotation validation EE-5021 (#8818)

app/react/kubernetes/ingresses/CreateIngressView/CreateIngressView.tsx

@@ -339,14 +339,41 @@ export function CreateIngressView() {
       }
 
       const duplicatedAnnotations: string[] = [];
+      const re = /^([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]$/;
       rule.Annotations?.forEach((a, i) => {
         if (!a.Key) {
-          errors[`annotations.key[${i}]`] = 'Annotation key is required';
+          errors[`annotations.key[${i}]`] = 'Key is required.';
         } else if (duplicatedAnnotations.includes(a.Key)) {
-          errors[`annotations.key[${i}]`] = 'Annotation cannot be duplicated';
+          errors[`annotations.key[${i}]`] =
+            'Key is a duplicate of an existing one.';
+        } else {
+          const key = a.Key.split('/');
+          if (key.length > 2) {
+            errors[`annotations.key[${i}]`] =
+              'Two segments are allowed, separated by a slash (/): a prefix (optional) and a name.';
+          } else if (key.length === 2) {
+            if (key[0].length > 253) {
+              errors[`annotations.key[${i}]`] =
+                "Prefix (before the slash) can't exceed 253 characters.";
+            } else if (key[1].length > 63) {
+              errors[`annotations.key[${i}]`] =
+                "Name (after the slash) can't exceed 63 characters.";
+            } else if (!re.test(key[1])) {
+              errors[`annotations.key[${i}]`] =
+                'Start and end with alphanumeric characters only, limiting characters in between to dashes, underscores, and alphanumerics.';
+            }
+          } else if (key.length === 1) {
+            if (key[0].length > 63) {
+              errors[`annotations.key[${i}]`] =
+                "Name (the segment after a slash (/), or only segment if no slash) can't exceed 63 characters.";
+            } else if (!re.test(key[0])) {
+              errors[`annotations.key[${i}]`] =
+                'Start and end with alphanumeric characters only, limiting characters in between to dashes, underscores, and alphanumerics.';
+            }
+          }
         }
         if (!a.Value) {
-          errors[`annotations.value[${i}]`] = 'Annotation value is required';
+          errors[`annotations.value[${i}]`] = 'Value is required.';
         }
         duplicatedAnnotations.push(a.Key);
       });