1 files changed, 137 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/agent/discovery/sd/discoverer/kubernetes/sim_test.go b/src/go/collectors/go.d.plugin/agent/discovery/sd/discoverer/kubernetes/sim_test.go
new file mode 100644
index 000000000..db986b855
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/agent/discovery/sd/discoverer/kubernetes/sim_test.go
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package kubernetes
+
+import (
+	"context"
+	"sort"
+	"testing"
+	"time"
+
+	"github.com/netdata/netdata/go/go.d.plugin/agent/discovery/sd/model"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"k8s.io/client-go/tools/cache"
+)
+
+const (
+	startWaitTimeout  = time.Second * 3
+	finishWaitTimeout = time.Second * 5
+)
+
+type discoverySim struct {
+	td               *KubeDiscoverer
+	runAfterSync     func(ctx context.Context)
+	sortBeforeVerify bool
+	wantTargetGroups []model.TargetGroup
+}
+
+func (sim discoverySim) run(t *testing.T) []model.TargetGroup {
+	t.Helper()
+	require.NotNil(t, sim.td)
+	require.NotEmpty(t, sim.wantTargetGroups)
+
+	in, out := make(chan []model.TargetGroup), make(chan []model.TargetGroup)
+	go sim.collectTargetGroups(t, in, out)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	go sim.td.Discover(ctx, in)
+
+	select {
+	case <-sim.td.started:
+	case <-time.After(startWaitTimeout):
+		t.Fatalf("td %s failed to start in %s", sim.td.discoverers, startWaitTimeout)
+	}
+
+	synced := cache.WaitForCacheSync(ctx.Done(), sim.td.hasSynced)
+	require.Truef(t, synced, "td %s failed to sync", sim.td.discoverers)
+
+	if sim.runAfterSync != nil {
+		sim.runAfterSync(ctx)
+	}
+
+	groups := <-out
+
+	if sim.sortBeforeVerify {
+		sortTargetGroups(groups)
+	}
+
+	sim.verifyResult(t, groups)
+	return groups
+}
+
+func (sim discoverySim) collectTargetGroups(t *testing.T, in, out chan []model.TargetGroup) {
+	var tggs []model.TargetGroup
+loop:
+	for {
+		select {
+		case inGroups := <-in:
+			if tggs = append(tggs, inGroups...); len(tggs) >= len(sim.wantTargetGroups) {
+				break loop
+			}
+		case <-time.After(finishWaitTimeout):
+			t.Logf("td %s timed out after %s, got %d groups, expected %d, some events are skipped",
+				sim.td.discoverers, finishWaitTimeout, len(tggs), len(sim.wantTargetGroups))
+			break loop
+		}
+	}
+	out <- tggs
+}
+
+func (sim discoverySim) verifyResult(t *testing.T, result []model.TargetGroup) {
+	var expected, actual any
+
+	if len(sim.wantTargetGroups) == len(result) {
+		expected = sim.wantTargetGroups
+		actual = result
+	} else {
+		want := make(map[string]model.TargetGroup)
+		for _, group := range sim.wantTargetGroups {
+			want[group.Source()] = group
+		}
+		got := make(map[string]model.TargetGroup)
+		for _, group := range result {
+			got[group.Source()] = group
+		}
+		expected, actual = want, got
+	}
+
+	assert.Equal(t, expected, actual)
+}
+
+type hasSynced interface {
+	hasSynced() bool
+}
+
+var (
+	_ hasSynced = &KubeDiscoverer{}
+	_ hasSynced = &podDiscoverer{}
+	_ hasSynced = &serviceDiscoverer{}
+)
+
+func (d *KubeDiscoverer) hasSynced() bool {
+	for _, disc := range d.discoverers {
+		v, ok := disc.(hasSynced)
+		if !ok || !v.hasSynced() {
+			return false
+		}
+	}
+	return true
+}
+
+func (p *podDiscoverer) hasSynced() bool {
+	return p.podInformer.HasSynced() && p.cmapInformer.HasSynced() && p.secretInformer.HasSynced()
+}
+
+func (s *serviceDiscoverer) hasSynced() bool {
+	return s.informer.HasSynced()
+}
+
+func sortTargetGroups(tggs []model.TargetGroup) {
+	if len(tggs) == 0 {
+		return
+	}
+	sort.Slice(tggs, func(i, j int) bool { return tggs[i].Source() < tggs[j].Source() })
+}