Add knative client to kubeclient library

app/models/clusters/applications/knative.rb

@@ -41,6 +41,10 @@ module Clusters
         )
       end
 
+      def client
+        cluster.platform_kubernetes.kubeclient.knative_client
+      end
+
       private
 
       def install_script

changelogs/unreleased/triggermesh-phase2-serverless.yml

+---
+title: Add knative client to kubeclient library
+merge_request: 22968
+author: cab105
+type: added

lib/gitlab/kubernetes/kube_client.rb

@@ -16,7 +16,8 @@ module Gitlab
       SUPPORTED_API_GROUPS = {
         core: { group: 'api', version: 'v1' },
         rbac: { group: 'apis/rbac.authorization.k8s.io', version: 'v1' },
-        extensions: { group: 'apis/extensions', version: 'v1beta1' }
+        extensions: { group: 'apis/extensions', version: 'v1beta1' },
+        knative: { group: 'apis/serving.knative.dev', version: 'v1alpha1' }
       }.freeze
 
       SUPPORTED_API_GROUPS.each do |name, params|

spec/lib/gitlab/kubernetes/kube_client_spec.rb

@@ -66,6 +66,20 @@ describe Gitlab::Kubernetes::KubeClient do
     end
   end
 
+  describe '#knative_client' do
+    subject { client.knative_client }
+
+    it_behaves_like 'a Kubeclient'
+
+    it 'has the extensions API group endpoint' do
+      expect(subject.api_endpoint.to_s).to match(%r{\/apis\/serving.knative.dev\Z})
+    end
+
+    it 'has the api_version' do
+      expect(subject.instance_variable_get(:@api_version)).to eq('v1alpha1')
+    end
+  end
+
   describe 'core API' do
     let(:core_client) { client.core_client }
 

spec/support/helpers/kubernetes_helpers.rb

@@ -17,6 +17,7 @@ module KubernetesHelpers
     WebMock.stub_request(:get, api_url + '/api/v1').to_return(kube_response(kube_v1_discovery_body))
     WebMock.stub_request(:get, api_url + '/apis/extensions/v1beta1').to_return(kube_response(kube_v1beta1_discovery_body))
     WebMock.stub_request(:get, api_url + '/apis/rbac.authorization.k8s.io/v1').to_return(kube_response(kube_v1_rbac_authorization_discovery_body))
+    WebMock.stub_request(:get, api_url + '/apis/serving.knative.dev/v1alpha1').to_return(kube_response(kube_v1alpha1_serving_knative_discovery_body))
   end
 
   def stub_kubeclient_pods(response = nil)
@@ -134,6 +135,18 @@ module KubernetesHelpers
     }
   end
 
+  def kube_v1alpha1_serving_knative_discovery_body
+    {
+      "kind" => "APIResourceList",
+      "resources" => [
+        { "name" => "revisions", "namespaced" => true, "kind" => "Revision" },
+        { "name" => "services", "namespaced" => true, "kind" => "Service" },
+        { "name" => "configurations", "namespaced" => true, "kind" => "Configuration" },
+        { "name" => "routes", "namespaced" => true, "kind" => "Route" }
+      ]
+    }
+  end
+
   def kube_pods_body
     {
       "kind" => "PodList",