Replace the disabled stack templates yaml test with java rest test (#…

…99978)

x-pack/plugin/core/src/javaRestTest/java/org/elasticsearch/xpack/core/StackTemplatesRestIT.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+package org.elasticsearch.xpack.core;
+
+import org.elasticsearch.client.Request;
+import org.elasticsearch.client.ResponseException;
+import org.elasticsearch.client.RestClient;
+import org.elasticsearch.common.settings.SecureString;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.test.rest.ESRestTestCase;
+
+import static org.hamcrest.Matchers.is;
+
+public class StackTemplatesRestIT extends ESRestTestCase {
+
+    private static final String BASIC_AUTH_VALUE = basicAuthHeaderValue("x_pack_rest_user", new SecureString("x-pack-test-password"));
+
+    @Override
+    protected Settings restClientSettings() {
+        return Settings.builder().put(ThreadContext.PREFIX + ".Authorization", BASIC_AUTH_VALUE).build();
+    }
+
+    public void testTemplatesCanBeDisabled() throws Exception {
+        RestClient client = client();
+        // Ensure the logs template has been added
+        assertBusy(() -> {
+            try {
+                Request request = new Request("GET", "_index_template/logs");
+                assertOK(client.performRequest(request));
+            } catch (ResponseException e) {
+                fail(e.getMessage());
+            }
+        });
+        // Disable the stack templates
+        {
+            Request request = new Request("PUT", "_cluster/settings");
+            request.setJsonEntity("""
+                {
+                  "persistent": {
+                    "stack.templates.enabled": false
+                  }
+                }
+                """);
+            assertOK(client.performRequest(request));
+        }
+        Request getRequest = new Request("GET", "_index_template/logs");
+        assertOK(client.performRequest(getRequest));
+
+        Request deleteRequest = new Request("DELETE", "_index_template/logs");
+        assertOK(client.performRequest(deleteRequest));
+        ResponseException exception = expectThrows(ResponseException.class, () -> client.performRequest(deleteRequest));
+        assertThat(exception.getResponse().getStatusLine().getStatusCode(), is(404));
+    }
+}