Add NodeCount to telemetry data

deployments/rbac/rbac.yaml

@@ -54,6 +54,12 @@ rules:
   - get
   - list
   - watch
+- apiGroups:
+  - ""
+  resources:
+  - nodes
+  verbs:
+  - list
 - apiGroups:
   - ""
   resources:

internal/telemetry/cluster.go

@@ -0,0 +1,17 @@
+package telemetry
+
+import (
+	"context"
+
+	metaV1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// NodeCount returns the total number of nodes in the cluster.
+// It returns an error if the underlying k8s API client errors.
+func (c *Collector) NodeCount(ctx context.Context) (int, error) {
+	nodes, err := c.Config.K8sClientReader.CoreV1().Nodes().List(ctx, metaV1.ListOptions{})
+	if err != nil {
+		return 0, err
+	}
+	return len(nodes.Items), nil
+}

internal/telemetry/cluster_test.go

@@ -0,0 +1,94 @@
+package telemetry_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/nginxinc/kubernetes-ingress/internal/telemetry"
+	apiCoreV1 "k8s.io/api/core/v1"
+	metaV1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	testClient "k8s.io/client-go/kubernetes/fake"
+)
+
+func TestNodeCountInAClusterWithThreeNodes(t *testing.T) {
+	t.Parallel()
+
+	c := newTestCollectorForCluserWithNodes(t, node1, node2, node3)
+
+	got, err := c.NodeCount(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := 3
+	if want != got {
+		t.Errorf("want %v, got %v", want, got)
+	}
+}
+
+func TestNodeCountInAClusterWithOneNode(t *testing.T) {
+	t.Parallel()
+
+	c := newTestCollectorForCluserWithNodes(t, node1)
+	got, err := c.NodeCount(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := 1
+	if want != got {
+		t.Errorf("want %v, got %v", want, got)
+	}
+}
+
+// newTestCollectorForClusterWithNodes returns a telemetry collector configured
+// to simulate collecting data on a cluser with provided nodes.
+func newTestCollectorForCluserWithNodes(t *testing.T, nodes ...runtime.Object) *telemetry.Collector {
+	t.Helper()
+
+	c, err := telemetry.NewCollector(
+		telemetry.CollectorConfig{},
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c.Config.K8sClientReader = testClient.NewSimpleClientset(nodes...)
+	return c
+}
+
+var (
+	node1 = &apiCoreV1.Node{
+		TypeMeta: metaV1.TypeMeta{
+			Kind:       "Node",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metaV1.ObjectMeta{
+			Name:      "test-node-1",
+			Namespace: "default",
+		},
+		Spec: apiCoreV1.NodeSpec{},
+	}
+
+	node2 = &apiCoreV1.Node{
+		TypeMeta: metaV1.TypeMeta{
+			Kind:       "Node",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metaV1.ObjectMeta{
+			Name:      "test-node-2",
+			Namespace: "default",
+		},
+		Spec: apiCoreV1.NodeSpec{},
+	}
+
+	node3 = &apiCoreV1.Node{
+		TypeMeta: metaV1.TypeMeta{
+			Kind:       "Node",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metaV1.ObjectMeta{
+			Name:      "test-node-3",
+			Namespace: "default",
+		},
+		Spec: apiCoreV1.NodeSpec{},
+	}
+)

internal/telemetry/collector.go

@@ -79,8 +79,7 @@ func (c *Collector) Start(ctx context.Context) {
 // It exports data using provided exporter.
 func (c *Collector) Collect(ctx context.Context) {
 	glog.V(3).Info("Collecting telemetry data")
-	// TODO: Re-add ctx to BuildReport when collecting Node Count.
-	data, err := c.BuildReport()
+	data, err := c.BuildReport(ctx)
 	if err != nil {
 		glog.Errorf("Error collecting telemetry data: %v", err)
 	}
@@ -92,13 +91,18 @@ func (c *Collector) Collect(ctx context.Context) {
 }
 
 // BuildReport takes context and builds report from gathered telemetry data.
-func (c *Collector) BuildReport() (Data, error) {
+func (c *Collector) BuildReport(ctx context.Context) (Data, error) {
 	d := Data{}
 	var err error
 
 	if c.Config.Configurator != nil {
 		d.NICResourceCounts.VirtualServers, d.NICResourceCounts.VirtualServerRoutes = c.Config.Configurator.GetVirtualServerCounts()
 		d.NICResourceCounts.TransportServers = c.Config.Configurator.GetTransportServerCounts()
 	}
+	nc, err := c.NodeCount(ctx)
+	if err != nil {
+		glog.Errorf("Error collecting telemetry data: Nodes: %v", err)
+	}
+	d.NodeCount = nc
 	return d, err
 }

internal/telemetry/collector_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/nginxinc/kubernetes-ingress/internal/telemetry"
 	conf_v1 "github.com/nginxinc/kubernetes-ingress/pkg/apis/configuration/v1"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	testClient "k8s.io/client-go/kubernetes/fake"
 )
 
 func TestCreateNewCollectorWithCustomReportingPeriod(t *testing.T) {
@@ -46,7 +47,8 @@ func TestCreateNewCollectorWithCustomExporter(t *testing.T) {
 	td := telemetry.Data{}
 
 	cfg := telemetry.CollectorConfig{
-		Configurator: newConfigurator(t),
+		K8sClientReader: testClient.NewSimpleClientset(),
+		Configurator:    newConfigurator(t),
 	}
 
 	c, err := telemetry.NewCollector(cfg, telemetry.WithExporter(exp))
@@ -62,6 +64,76 @@ func TestCreateNewCollectorWithCustomExporter(t *testing.T) {
 	}
 }
 
+func TestCollectNodeCountInClusterWithOneNode(t *testing.T) {
+	t.Parallel()
+
+	buf := &bytes.Buffer{}
+	exp := &telemetry.StdoutExporter{Endpoint: buf}
+	cfg := telemetry.CollectorConfig{
+		Configurator:    newConfigurator(t),
+		K8sClientReader: testClient.NewSimpleClientset(node1),
+	}
+
+	c, err := telemetry.NewCollector(cfg, telemetry.WithExporter(exp))
+	if err != nil {
+		t.Fatal(err)
+	}
+	c.Collect(context.Background())
+
+	td := telemetry.Data{
+		ProjectMeta: telemetry.ProjectMeta{
+			Name:    "",
+			Version: "",
+		},
+		NICResourceCounts: telemetry.NICResourceCounts{
+			VirtualServers:      0,
+			VirtualServerRoutes: 0,
+			TransportServers:    0,
+		},
+		NodeCount: 1,
+	}
+	want := fmt.Sprintf("%+v", td)
+	got := buf.String()
+	if !cmp.Equal(want, got) {
+		t.Error(cmp.Diff(want, got))
+	}
+}
+
+func TestCollectNodeCountInClusterWithThreeNodes(t *testing.T) {
+	t.Parallel()
+
+	buf := &bytes.Buffer{}
+	exp := &telemetry.StdoutExporter{Endpoint: buf}
+	cfg := telemetry.CollectorConfig{
+		Configurator:    newConfigurator(t),
+		K8sClientReader: testClient.NewSimpleClientset(node1, node2, node3),
+	}
+
+	c, err := telemetry.NewCollector(cfg, telemetry.WithExporter(exp))
+	if err != nil {
+		t.Fatal(err)
+	}
+	c.Collect(context.Background())
+
+	td := telemetry.Data{
+		ProjectMeta: telemetry.ProjectMeta{
+			Name:    "",
+			Version: "",
+		},
+		NICResourceCounts: telemetry.NICResourceCounts{
+			VirtualServers:      0,
+			VirtualServerRoutes: 0,
+			TransportServers:    0,
+		},
+		NodeCount: 3,
+	}
+	want := fmt.Sprintf("%+v", td)
+	got := buf.String()
+	if !cmp.Equal(want, got) {
+		t.Error(cmp.Diff(want, got))
+	}
+}
+
 func TestCountVirtualServers(t *testing.T) {
 	t.Parallel()
 
@@ -171,7 +243,8 @@ func TestCountVirtualServers(t *testing.T) {
 		configurator := newConfigurator(t)
 
 		c, err := telemetry.NewCollector(telemetry.CollectorConfig{
-			Configurator: configurator,
+			K8sClientReader: testClient.NewSimpleClientset(),
+			Configurator:    configurator,
 		})
 		if err != nil {
 			t.Fatal(err)
@@ -184,7 +257,7 @@ func TestCountVirtualServers(t *testing.T) {
 			}
 		}
 
-		gotTraceDataOnAdd, err := c.BuildReport()
+		gotTraceDataOnAdd, err := c.BuildReport(context.Background())
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -202,7 +275,7 @@ func TestCountVirtualServers(t *testing.T) {
 			}
 		}
 
-		gotTraceDataOnDelete, err := c.BuildReport()
+		gotTraceDataOnDelete, err := c.BuildReport(context.Background())
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -342,7 +415,8 @@ func TestCountTransportServers(t *testing.T) {
 		configurator := newConfigurator(t)
 
 		c, err := telemetry.NewCollector(telemetry.CollectorConfig{
-			Configurator: configurator,
+			K8sClientReader: testClient.NewSimpleClientset(),
+			Configurator:    configurator,
 		})
 		if err != nil {
 			t.Fatal(err)
@@ -355,7 +429,7 @@ func TestCountTransportServers(t *testing.T) {
 			}
 		}
 
-		gotTraceDataOnAdd, err := c.BuildReport()
+		gotTraceDataOnAdd, err := c.BuildReport(context.Background())
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -373,7 +447,7 @@ func TestCountTransportServers(t *testing.T) {
 			}
 		}
 
-		gotTraceDataOnDelete, err := c.BuildReport()
+		gotTraceDataOnDelete, err := c.BuildReport(context.Background())
 		if err != nil {
 			t.Fatal(err)
 		}

internal/telemetry/exporter.go

@@ -29,6 +29,7 @@ func (e *StdoutExporter) Export(_ context.Context, data Data) error {
 type Data struct {
 	ProjectMeta       ProjectMeta
 	NICResourceCounts NICResourceCounts
+	NodeCount         int
 }
 
 // ProjectMeta holds metadata for the project.