add unit test from code copilot

.github/workflows/unit.yaml

@@ -0,0 +1,33 @@
+# .github/workflows/test.yml
+name: Go Unit Tests
+
+on:
+  push:
+    branches:
+      - feat/unittests
+  pull_request:
+    branches:
+      - feat/unittests
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Setup Go
+      uses: actions/setup-go@v4
+      with:
+        go-version: "1.19"
+    - name: Install dependencies
+      run: go mod tidy
+    - name: Run tests
+      run: go test -v ./... -coverprofile=coverage.out
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v3
+      with:
+        files: coverage.out
+        flags: unittests
+        fail_ci_if_error: true
+    - name: Generate coverage badge
+      run: go tool cover -func coverage.out
+

overlay_test.go

@@ -0,0 +1,82 @@
+// overlay_test.go
+package main
+
+import (
+	"context"
+	"testing"
+
+	apps "k8s.io/api/apps/v1"
+	core "k8s.io/api/core/v1"
+	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
+)
+
+func TestCreateDaemonSet(t *testing.T) {
+	clientset := fake.NewSimpleClientset()
+	namespace := "kube-system"
+	app := "overlaytest"
+
+	daemonset := &apps.DaemonSet{
+		ObjectMeta: meta.ObjectMeta{
+			Name: app,
+		},
+		Spec: apps.DaemonSetSpec{
+			Selector: &meta.LabelSelector{
+				MatchLabels: map[string]string{
+					"app": app,
+				},
+			},
+			Template: core.PodTemplateSpec{
+				ObjectMeta: meta.ObjectMeta{
+					Labels: map[string]string{
+						"app": app,
+					},
+				},
+				Spec: core.PodSpec{
+					Containers: []core.Container{
+						{
+							Name:  app,
+							Image: "test-image",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	_, err := clientset.AppsV1().DaemonSets(namespace).Create(context.TODO(), daemonset, meta.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Failed to create DaemonSet: %v", err)
+	}
+
+	_, err = clientset.AppsV1().DaemonSets(namespace).Get(context.TODO(), app, meta.GetOptions{})
+	if err != nil {
+		t.Fatalf("Failed to get DaemonSet: %v", err)
+	}
+}
+
+func TestListPods(t *testing.T) {
+	clientset := fake.NewSimpleClientset(
+		&core.Pod{
+			ObjectMeta: meta.ObjectMeta{
+				Name:      "test-pod",
+				Namespace: "kube-system",
+				Labels:    map[string]string{"app": "overlaytest"},
+			},
+			Status: core.PodStatus{
+				PodIP: "192.168.1.1",
+			},
+		},
+	)
+
+	pods, err := clientset.CoreV1().Pods("kube-system").List(context.TODO(), meta.ListOptions{
+		LabelSelector: "app=overlaytest",
+	})
+	if err != nil {
+		t.Fatalf("Failed to list Pods: %v", err)
+	}
+
+	if len(pods.Items) != 1 {
+		t.Fatalf("Expected 1 pod, got %d", len(pods.Items))
+	}
+}