1 files changed, 86 insertions, 0 deletions
diff --git a/spec/support/shared_examples/models/clusters/prometheus_client_shared.rb b/spec/support/shared_examples/models/clusters/prometheus_client_shared.rb
new file mode 100644
index 00000000000..8d6dcfef925
--- /dev/null
+++ b/spec/support/shared_examples/models/clusters/prometheus_client_shared.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+# Input
+#  - factory: [:clusters_applications_prometheus, :clusters_integrations_prometheus]
+RSpec.shared_examples '#prometheus_client shared' do
+  shared_examples 'exception caught for prometheus client' do
+    before do
+      allow(kube_client).to receive(:proxy_url).and_raise(exception)
+    end
+
+    it 'returns nil' do
+      expect(subject.prometheus_client).to be_nil
+    end
+  end
+
+  context 'cluster is nil' do
+    it 'returns nil' do
+      expect(subject.cluster).to be_nil
+      expect(subject.prometheus_client).to be_nil
+    end
+  end
+
+  context "cluster doesn't have kubeclient" do
+    let(:cluster) { create(:cluster) }
+
+    subject { create(factory, cluster: cluster) }
+
+    it 'returns nil' do
+      expect(subject.prometheus_client).to be_nil
+    end
+  end
+
+  context 'cluster has kubeclient' do
+    let(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+    let(:kubernetes_url) { subject.cluster.platform_kubernetes.api_url }
+    let(:kube_client) { subject.cluster.kubeclient.core_client }
+
+    subject { create(factory, cluster: cluster) }
+
+    before do
+      subject.cluster.platform_kubernetes.namespace = 'a-namespace'
+      stub_kubeclient_discover(cluster.platform_kubernetes.api_url)
+
+      create(:cluster_kubernetes_namespace,
+             cluster: cluster,
+             cluster_project: cluster.cluster_project,
+             project: cluster.cluster_project.project)
+    end
+
+    it 'creates proxy prometheus_client' do
+      expect(subject.prometheus_client).to be_instance_of(Gitlab::PrometheusClient)
+    end
+
+    it 'merges proxy_url, options and headers from kube client with prometheus_client options' do
+      expect(Gitlab::PrometheusClient)
+        .to(receive(:new))
+        .with(a_valid_url, kube_client.rest_client.options.merge({
+        headers: kube_client.headers,
+        timeout: PrometheusAdapter::DEFAULT_PROMETHEUS_REQUEST_TIMEOUT_SEC
+      }))
+      subject.prometheus_client
+    end
+
+    context 'when cluster is not reachable' do
+      it_behaves_like 'exception caught for prometheus client' do
+        let(:exception) { Kubeclient::HttpError.new(401, 'Unauthorized', nil) }
+      end
+    end
+
+    context 'when there is a socket error while contacting cluster' do
+      it_behaves_like 'exception caught for prometheus client' do
+        let(:exception) { Errno::ECONNREFUSED }
+      end
+
+      it_behaves_like 'exception caught for prometheus client' do
+        let(:exception) { Errno::ECONNRESET }
+      end
+    end
+
+    context 'when the network is unreachable' do
+      it_behaves_like 'exception caught for prometheus client' do
+        let(:exception) { Errno::ENETUNREACH }
+      end
+    end
+  end
+end