[Website 2.0] Nightly Build for v2.x (master) (#17957)

* Added Jenkinsfile for nightly builds

* Reduced node labels to utility and linux_cpu

ci/jenkins/Jenkinsfile_website_nightly

@@ -0,0 +1,63 @@
+// -*- mode: groovy -*-
+
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+//
+// Jenkins pipeline
+// See documents at https://jenkins.io/doc/book/pipeline/jenkinsfile/
+
+// timeout in minutes
+max_time = 180
+
+node('restricted-utility') {
+  // Loading the utilities requires a node context unfortunately
+  checkout scm
+  utils = load('ci/Jenkinsfile_utils.groovy')
+  custom_steps = load('ci/jenkins/Jenkins_steps.groovy')
+}
+
+utils.assign_node_labels(utility: 'restricted-utility', linux_cpu: 'restricted-mxnetlinux-cpu')
+
+utils.main_wrapper(
+core_logic: {
+  utils.parallel_stage('Build', [
+    custom_steps.compile_unix_lite()
+  ])
+
+  utils.parallel_stage('Build Docs', [
+    custom_steps.docs_jekyll(),
+    custom_steps.docs_c(),
+    custom_steps.docs_python(),
+    custom_steps.docs_julia(),
+    custom_steps.docs_r(),
+    custom_steps.docs_scala(),
+    custom_steps.docs_java(),
+    custom_steps.docs_clojure()
+  ])
+
+  utils.parallel_stage('Prepare', [
+    custom_steps.docs_prepare()
+  ])
+}
+,
+failure_handler: {
+  // Only send email if master or release branches failed
+  if (currentBuild.result == "FAILURE" && (env.BRANCH_NAME == "master" || env.BRANCH_NAME.startsWith("v"))) {
+    emailext body: 'Build for MXNet branch ${BRANCH_NAME} has broken. Please view the build at ${BUILD_URL}', replyTo: '${EMAIL}', subject: '[BUILD FAILED] Branch ${BRANCH_NAME} build ${BUILD_NUMBER}', to: '${EMAIL}'
+  }
+}
+)