nodes: add wait until node selected

This PR adds WaitUntilNodeSelected which allows for waiting until a node can be selected by provided ListOptions. Additionally, unit tests for this function and the List function are included.

Author: klaskosk

pkg/nodes/list.go

@@ -18,6 +18,12 @@ const (
 
 // List returns node inventory.
 func List(apiClient *clients.Settings, options ...metav1.ListOptions) ([]*Builder, error) {
+	if apiClient == nil {
+		glog.V(100).Infof("Nodes 'apiClient' parameter can not be empty")
+
+		return nil, fmt.Errorf("failed to list node objects, 'apiClient' parameter is empty")
+	}
+
 	passedOptions := metav1.ListOptions{}
 	logMessage := "Listing all node resources"
 
@@ -186,3 +192,29 @@ func WaitForAllNodesToReboot(apiClient *clients.Settings,
 
 	return false, err
 }
+
+// WaitUntilNodeSelected waits up to timeout until a node is selected by the provided options.
+func WaitUntilNodeSelected(apiClient *clients.Settings, options metav1.ListOptions, timeout time.Duration) error {
+	if apiClient == nil {
+		glog.V(100).Infof("Nodes 'apiClient' parameter can not be empty")
+
+		return fmt.Errorf("nodes apiClient parameter is empty")
+	}
+
+	glog.V(100).Info("Waiting up to %v for any nodes to be selected by options %v", timeout, options)
+
+	return wait.PollUntilContextTimeout(context.TODO(), backoff, timeout, true, func(ctx context.Context) (bool, error) {
+		nodes, err := List(apiClient, options)
+		if err != nil {
+			return false, nil
+		}
+
+		if len(nodes) == 0 {
+			return false, nil
+		}
+
+		glog.V(100).Infof("Found %d nodes matching provided options", len(nodes))
+
+		return true, nil
+	})
+}

pkg/nodes/list_test.go

@@ -0,0 +1,108 @@
+package nodes
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/openshift-kni/eco-goinfra/pkg/clients"
+	"github.com/stretchr/testify/assert"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+func TestList(t *testing.T) {
+	testCases := []struct {
+		nodes         []*Builder
+		listOptions   []metav1.ListOptions
+		client        bool
+		expectedError error
+	}{
+		{
+			nodes:         []*Builder{buildValidNodeTestBuilder(buildTestClientWithDummyNode())},
+			listOptions:   nil,
+			client:        true,
+			expectedError: nil,
+		},
+		{
+			nodes:         []*Builder{buildValidNodeTestBuilder(buildTestClientWithDummyNode())},
+			listOptions:   []metav1.ListOptions{{LabelSelector: "test"}},
+			client:        true,
+			expectedError: nil,
+		},
+		{
+			nodes:         []*Builder{buildValidNodeTestBuilder(buildTestClientWithDummyNode())},
+			listOptions:   []metav1.ListOptions{{LabelSelector: "test"}, {LabelSelector: "test"}},
+			client:        true,
+			expectedError: fmt.Errorf("error: more than one ListOptions was passed"),
+		},
+		{
+			nodes:         []*Builder{buildValidNodeTestBuilder(buildTestClientWithDummyNode())},
+			listOptions:   nil,
+			client:        false,
+			expectedError: fmt.Errorf("failed to list node objects, 'apiClient' parameter is empty"),
+		},
+	}
+
+	for _, testCase := range testCases {
+		var testSettings *clients.Settings
+
+		if testCase.client {
+			testSettings = buildTestClientWithDummyNode()
+		}
+
+		nodeBuilders, err := List(testSettings, testCase.listOptions...)
+		assert.Equal(t, err, testCase.expectedError)
+
+		if testCase.expectedError == nil && len(testCase.listOptions) == 0 {
+			assert.Equal(t, len(nodeBuilders), len(testCase.nodes))
+		}
+	}
+}
+
+func TestWaitUntilNodeSelected(t *testing.T) {
+	testCases := []struct {
+		selected      bool
+		client        bool
+		expectedError error
+	}{
+		{
+			selected:      true,
+			client:        true,
+			expectedError: nil,
+		},
+		{
+			selected:      false,
+			client:        true,
+			expectedError: context.DeadlineExceeded,
+		},
+		{
+			selected:      true,
+			client:        false,
+			expectedError: fmt.Errorf("nodes apiClient parameter is empty"),
+		},
+	}
+
+	for _, testCase := range testCases {
+		var testSettings *clients.Settings
+
+		if testCase.client {
+			node := buildDummyNode(defaultNodeName)
+
+			if testCase.selected {
+				node.Labels = map[string]string{defaultNodeLabel: ""}
+			}
+
+			testSettings = clients.GetTestClients(clients.TestClientParams{
+				K8sMockObjects: []runtime.Object{node},
+			})
+		}
+
+		err := WaitUntilNodeSelected(testSettings, metav1.ListOptions{
+			LabelSelector: fmt.Sprintf("%s=", defaultNodeLabel),
+		}, time.Second)
+
+		assert.Equal(t, testCase.expectedError, err)
+	}
+}

pkg/nodes/nodes_test.go

@@ -1 +1,47 @@
 package nodes
+
+import (
+	"github.com/openshift-kni/eco-goinfra/pkg/clients"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+const (
+	defaultNodeName  = "test-node"
+	defaultNodeLabel = "node-role.kubernetes.io/control-plane"
+)
+
+// buildDummyNode returns a Node with the provided name.
+func buildDummyNode(name string) *corev1.Node {
+	return &corev1.Node{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: name,
+		},
+	}
+}
+
+// buildTestClientWithDummyNode returns a client with a dummy node.
+func buildTestClientWithDummyNode() *clients.Settings {
+	return clients.GetTestClients(clients.TestClientParams{
+		K8sMockObjects: []runtime.Object{buildDummyNode(defaultNodeName)},
+	})
+}
+
+func buildValidNodeTestBuilder(apiClient *clients.Settings) *Builder {
+	return newNodeBuilder(apiClient, defaultNodeName)
+}
+
+// newNodeBuilder creates a new Builder instances for testing purposes.
+func newNodeBuilder(apiClient *clients.Settings, name string) *Builder {
+	if apiClient == nil {
+		return nil
+	}
+
+	builder := Builder{
+		apiClient:  apiClient.K8sClient,
+		Definition: buildDummyNode(name),
+	}
+
+	return &builder
+}