Introduce new kubernetes spec helpers

Add create_role_binding, create_namespace and get_namespace kubernetes
spec helpers.

This new helpers are going to be used on
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22011

changelogs/unreleased/add-new-kubernetes-spec-helpers.yml

+---
+title: Introduce new kubernetes helpers
+merge_request: 22525
+author:
+type: other

spec/support/helpers/kubernetes_helpers.rb

@@ -33,10 +33,11 @@ module KubernetesHelpers
     WebMock.stub_request(:get, deployments_url).to_return(response || kube_deployments_response)
   end
 
-  def stub_kubeclient_get_secret(api_url, namespace: 'default', **options)
+  def stub_kubeclient_get_secret(api_url, **options)
     options[:metadata_name] ||= "default-token-1"
+    options[:namespace] ||= "default"
 
-    WebMock.stub_request(:get, api_url + "/api/v1/namespaces/#{namespace}/secrets/#{options[:metadata_name]}")
+    WebMock.stub_request(:get, api_url + "/api/v1/namespaces/#{options[:namespace]}/secrets/#{options[:metadata_name]}")
       .to_return(kube_response(kube_v1_secret_body(options)))
   end
 
@@ -65,6 +66,21 @@ module KubernetesHelpers
       .to_return(kube_response({}))
   end
 
+  def stub_kubeclient_create_role_binding(api_url, namespace: 'default')
+    WebMock.stub_request(:post, api_url + "/apis/rbac.authorization.k8s.io/v1/namespaces/#{namespace}/rolebindings")
+      .to_return(kube_response({}))
+  end
+
+  def stub_kubeclient_create_namespace(api_url)
+    WebMock.stub_request(:post, api_url + "/api/v1/namespaces")
+      .to_return(kube_response({}))
+  end
+
+  def stub_kubeclient_get_namespace(api_url, namespace: 'default')
+    WebMock.stub_request(:get, api_url + "/api/v1/namespaces/#{namespace}")
+      .to_return(kube_response({}))
+  end
+
   def kube_v1_secret_body(**options)
     {
       "kind" => "SecretList",
@@ -87,7 +103,8 @@ module KubernetesHelpers
         { "name" => "deployments", "namespaced" => true, "kind" => "Deployment" },
         { "name" => "secrets", "namespaced" => true, "kind" => "Secret" },
         { "name" => "serviceaccounts", "namespaced" => true, "kind" => "ServiceAccount" },
-        { "name" => "services", "namespaced" => true, "kind" => "Service" }
+        { "name" => "services", "namespaced" => true, "kind" => "Service" },
+        { "name" => "namespaces", "namespaced" => true, "kind" => "Namespace" }
       ]
     }
   end