Fix throws nil runtime error when decode AdmissionReview failed

Signed-off-by: WillardHu <wei.hu@daocloud.io>

3 files changed, 77 insertions, 2 deletions

diff --git a/cloud/pkg/admissioncontroller/common.go b/cloud/pkg/admissioncontroller/common.go
index b7882ad45..f44205821 100644
--- a/cloud/pkg/admissioncontroller/common.go
+++ b/cloud/pkg/admissioncontroller/common.go
@@ -94,10 +94,10 @@ func serve(w http.ResponseWriter, r *http.Request, hook hookFunc) {
 		responseAdmissionReview.Response = toAdmissionResponse(err)
 	} else {
 		responseAdmissionReview.Response = hook(requestedAdmissionReview)
+		// Return the same UID
+		responseAdmissionReview.Response.UID = requestedAdmissionReview.Request.UID
 	}
 
-	// Return the same UID
-	responseAdmissionReview.Response.UID = requestedAdmissionReview.Request.UID
 	klog.V(4).Infof("sending response: %+v", responseAdmissionReview.Response)
 
 	respBytes, err := json.Marshal(responseAdmissionReview)
diff --git a/cloud/pkg/admissioncontroller/common_test.go b/cloud/pkg/admissioncontroller/common_test.go
new file mode 100644
index 000000000..888bbdeac
--- /dev/null
+++ b/cloud/pkg/admissioncontroller/common_test.go
@@ -0,0 +1,47 @@
+package admissioncontroller
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"testing"
+
+	admissionv1 "k8s.io/api/admission/v1"
+
+	"github.com/kubeedge/kubeedge/cloud/test/httpfake"
+)
+
+func TestServe(t *testing.T) {
+	w := httpfake.NewResponseWriter()
+	hookfn := func(admissionv1.AdmissionReview) *admissionv1.AdmissionResponse {
+		return &admissionv1.AdmissionResponse{Allowed: true}
+	}
+
+	t.Run("not json content-type", func(_ *testing.T) {
+		serve(w, &http.Request{
+			Header: map[string][]string{
+				"Content-Type": {"application/xml"},
+			},
+		}, hookfn)
+	})
+
+	t.Run("decode body failed", func(_ *testing.T) {
+		raw := "{"
+		serve(w, &http.Request{
+			Header: map[string][]string{
+				"Content-Type": {"application/json"},
+			},
+			Body: io.NopCloser(bytes.NewReader([]byte(raw))),
+		}, hookfn)
+	})
+
+	t.Run("handle hook func", func(_ *testing.T) {
+		raw := "{\"request\": {\"uid\": \"1\"}}"
+		serve(w, &http.Request{
+			Header: map[string][]string{
+				"Content-Type": {"application/json"},
+			},
+			Body: io.NopCloser(bytes.NewReader([]byte(raw))),
+		}, hookfn)
+	})
+}
diff --git a/cloud/test/httpfake/http_fake.go b/cloud/test/httpfake/http_fake.go
new file mode 100644
index 000000000..9a74d21e7
--- /dev/null
+++ b/cloud/test/httpfake/http_fake.go
@@ -0,0 +1,28 @@
+package httpfake
+
+import "net/http"
+
+type ResponseWriter struct {
+	HTTPHeader http.Header
+	Status     int
+	Body       []byte
+}
+
+func NewResponseWriter() *ResponseWriter {
+	return &ResponseWriter{
+		HTTPHeader: make(http.Header),
+	}
+}
+
+func (f *ResponseWriter) Header() http.Header {
+	return f.HTTPHeader
+}
+
+func (f *ResponseWriter) Write(b []byte) (int, error) {
+	f.Body = b
+	return len(b), nil
+}
+
+func (f *ResponseWriter) WriteHeader(statusCode int) {
+	f.Status = statusCode
+}