Tests: Introduce event package

This package can be used to safely expect
events on object. This allow us to expect
events even in parallel tests.

Note: Objects that are not namespaced or
shared between tests, such as nodes, disallow
us to use this package without running Serial.

Signed-off-by: L. Pivarc <[email protected]>

tests/events/BUILD.bazel

@@ -0,0 +1,18 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["events.go"],
+    importpath = "kubevirt.io/kubevirt/tests/events",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/kubevirt.io/client-go/kubecli:go_default_library",
+        "//tests/util:go_default_library",
+        "//vendor/github.com/onsi/ginkgo/v2:go_default_library",
+        "//vendor/github.com/onsi/gomega:go_default_library",
+        "//vendor/github.com/onsi/gomega/types:go_default_library",
+        "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+    ],
+)

tests/events/events.go

@@ -0,0 +1,106 @@
+package events
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"time"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/types"
+
+	"kubevirt.io/client-go/kubecli"
+
+	"kubevirt.io/kubevirt/tests/util"
+
+	k8sv1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+type k8sObject interface {
+	metav1.Object
+	schema.ObjectKind
+}
+
+// ExpectNoEvent is safe to use in parallel as long as you are asserting namespaced object that is not shared between tests
+func ExpectNoEvent(object k8sObject, eventType, reason string) {
+	By("Expecting for an event to be not triggered")
+	expectEvent(object, eventType, reason, BeEmpty())
+}
+
+// ExpectEvent is safe to use in parallel as long as you are asserting namespaced object that is not shared between tests
+func ExpectEvent(object k8sObject, eventType, reason string) {
+	By("Expecting for an event to be triggered")
+	expectEvent(object, eventType, reason, Not(BeEmpty()))
+}
+
+// DeleteEvents is safe to use in parallel as long as you are asserting namespaced object that is not shared between tests
+func DeleteEvents(object k8sObject, eventType, reason string) {
+	By("Expecting events to be removed")
+	virtClient, err := kubecli.GetKubevirtClient()
+	util.PanicOnError(err)
+
+	fieldSelector, namespace := constructFieldSelectorAndNamespace(object, eventType, reason)
+
+	events, err := virtClient.CoreV1().Events(namespace).List(context.Background(),
+		metav1.ListOptions{
+			FieldSelector: fieldSelector,
+		})
+	ExpectWithOffset(1, err).ToNot(HaveOccurred())
+	for _, event := range events.Items {
+		err = virtClient.CoreV1().Events(event.Namespace).Delete(
+			context.TODO(),
+			event.Name,
+			metav1.DeleteOptions{},
+		)
+		ExpectWithOffset(1, err).ToNot(HaveOccurred(), fmt.Sprintf("failed to delete event %s/%s", event.Namespace, event.Name))
+	}
+
+	EventuallyWithOffset(1, func() []k8sv1.Event {
+		events, err := virtClient.CoreV1().Events(namespace).List(context.Background(),
+			metav1.ListOptions{
+				FieldSelector: fieldSelector,
+			})
+		ExpectWithOffset(1, err).ToNot(HaveOccurred())
+
+		return events.Items
+	}, 30*time.Second, 1*time.Second).Should(BeEmpty(), fmt.Sprintf("Used fieldselector %s", fieldSelector))
+}
+
+func expectEvent(object k8sObject, eventType, reason string, matcher types.GomegaMatcher) {
+	virtClient, err := kubecli.GetKubevirtClient()
+	ExpectWithOffset(2, err).ToNot(HaveOccurred())
+
+	fieldSelector, namespace := constructFieldSelectorAndNamespace(object, eventType, reason)
+
+	EventuallyWithOffset(2, func() []k8sv1.Event {
+		events, err := virtClient.CoreV1().Events(namespace).List(
+			context.Background(),
+			metav1.ListOptions{
+				FieldSelector: fieldSelector,
+			},
+		)
+		ExpectWithOffset(3, err).ToNot(HaveOccurred())
+		return events.Items
+	}, 30*time.Second).Should(matcher, fmt.Sprintf("Used fieldselector %s", fieldSelector))
+}
+
+// constructFieldSelectorAndNamespace does best effort to overcome https://github.com/kubernetes/client-go/issues/861
+func constructFieldSelectorAndNamespace(object k8sObject, eventType, reason string) (string, string) {
+	kind := object.GroupVersionKind().Kind
+	if kind == "" {
+		kind = reflect.ValueOf(object).Type().Name()
+	}
+	kindSelector := fmt.Sprintf("involvedObject.kind=%s,", kind)
+	if kind == "" {
+		kindSelector = ""
+	}
+
+	name := object.GetName()
+	namespace := object.GetNamespace()
+
+	fieldSelector := fmt.Sprintf("%sinvolvedObject.name=%s,type=%s,reason=%s", kindSelector, name, eventType, reason)
+	return fieldSelector, namespace
+}