From d5835821c5c030c060460b8e17f6f4a9d22f946b Mon Sep 17 00:00:00 2001
From: Rob Watson <rob@netflux.io>
Date: Thu, 2 Jun 2022 19:23:47 +0200
Subject: [PATCH] podWatcher: add test coverage

---
 logs/pod_watcher_test.go | 148 +++++++++++++++++++++++++++++++++++++++
 logs/watcher_test.go     |   8 +--
 2 files changed, 152 insertions(+), 4 deletions(-)
 create mode 100644 logs/pod_watcher_test.go

diff --git a/logs/pod_watcher_test.go b/logs/pod_watcher_test.go
new file mode 100644
index 0000000..b4313c4
--- /dev/null
+++ b/logs/pod_watcher_test.go
@@ -0,0 +1,148 @@
+package logs_test
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"git.netflux.io/rob/kubectl-persistent-logger/logs"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/watch"
+	testclient "k8s.io/client-go/kubernetes/fake"
+	"k8s.io/client-go/kubernetes/scheme"
+	clientv1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/rest"
+	fakerest "k8s.io/client-go/rest/fake"
+	k8stest "k8s.io/client-go/testing"
+)
+
+type mockClientset struct {
+	testclient.Clientset
+	clientv1.CoreV1Interface
+	clientv1.PodInterface
+
+	podsWatcher       watch.Interface
+	getLogsStatusCode int
+	getLogsRespBody   string
+	getLogsErr        error
+}
+
+func (m *mockClientset) CoreV1() clientv1.CoreV1Interface  { return m }
+func (m *mockClientset) Pods(string) clientv1.PodInterface { return m }
+func (m *mockClientset) Watch(context.Context, metav1.ListOptions) (watch.Interface, error) {
+	return m.podsWatcher, nil
+}
+
+func (m *mockClientset) GetLogs(podName string, _ *corev1.PodLogOptions) *rest.Request {
+	fakeClient := fakerest.RESTClient{
+		Client: fakerest.CreateHTTPClient(func(*http.Request) (*http.Response, error) {
+			if m.getLogsErr != nil {
+				return nil, m.getLogsErr
+			}
+			return &http.Response{
+				StatusCode: m.getLogsStatusCode,
+				Body:       io.NopCloser(strings.NewReader(m.getLogsRespBody)),
+			}, nil
+		}),
+		NegotiatedSerializer: scheme.Codecs.WithoutConversion(),
+		VersionedAPIPath:     fmt.Sprintf("/api/v1/namespaces/default/pods/%s/log", podName),
+	}
+	return fakeClient.Request()
+}
+
+func TestPodWatcher(t *testing.T) {
+	testCases := []struct {
+		name              string
+		getLogsRespBody   string
+		getLogsStatusCode int
+		getLogsErr        error
+		wantOut           []string
+		wantErr           string
+	}{
+		{
+			name:       "unexpected error getting logs",
+			getLogsErr: errors.New("nope"),
+			wantOut:    nil,
+			wantErr:    "nope",
+		},
+		{
+			name:       "recoverable error getting logs",
+			getLogsErr: &apierrors.StatusError{ErrStatus: metav1.Status{Message: "is waiting to start: ContainerCreating", Reason: metav1.StatusReasonBadRequest}},
+			wantOut:    nil,
+			wantErr:    context.DeadlineExceeded.Error(),
+		},
+		{
+			name:              "success",
+			getLogsRespBody:   "some logs",
+			getLogsStatusCode: http.StatusOK,
+			wantOut:           []string{"[foo] some logs", "[bar] some logs"},
+			wantErr:           context.DeadlineExceeded.Error(),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+			defer cancel()
+
+			podsWatcher := watch.NewFake()
+			defer podsWatcher.Stop()
+
+			clientset := mockClientset{
+				getLogsRespBody:   tc.getLogsRespBody,
+				getLogsStatusCode: tc.getLogsStatusCode,
+				getLogsErr:        tc.getLogsErr,
+				podsWatcher:       podsWatcher,
+			}
+			clientset.PrependWatchReactor("pods", k8stest.DefaultWatchReactor(podsWatcher, nil))
+
+			client := logs.KubernetesClient{Interface: &clientset}
+			selector := metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}}
+
+			go func() {
+				pods := []*corev1.Pod{
+					{
+						ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "default"},
+						Status:     corev1.PodStatus{Phase: corev1.PodRunning},
+					},
+					{
+						ObjectMeta: metav1.ObjectMeta{Name: "bar", Namespace: "default"},
+						Status:     corev1.PodStatus{Phase: corev1.PodRunning},
+					},
+					{
+						ObjectMeta: metav1.ObjectMeta{Name: "baz", Namespace: "default"},
+						Status:     corev1.PodStatus{Phase: corev1.PodPending},
+					},
+				}
+				for _, pod := range pods {
+					podsWatcher.Add(pod)
+					time.Sleep(time.Millisecond * 250)
+				}
+			}()
+
+			var buf bytes.Buffer
+			pw := logs.NewPodWatcher(client, "mycontainer", &selector, &buf)
+
+			err := pw.WatchPods(ctx)
+
+			if tc.wantErr == "" {
+				require.NoError(t, err)
+			} else {
+				require.Contains(t, err.Error(), tc.wantErr)
+			}
+			if tc.wantOut != nil {
+				assert.ElementsMatch(t, tc.wantOut, splitBuf(&buf))
+			}
+		})
+	}
+}
diff --git a/logs/watcher_test.go b/logs/watcher_test.go
index 14852bf..1471d5f 100644
--- a/logs/watcher_test.go
+++ b/logs/watcher_test.go
@@ -68,14 +68,16 @@ func TestWatcherWithPodWatcher(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 
 	deploymentsWatcher := watch.NewFake()
+	defer deploymentsWatcher.Stop()
 	podsWatcher := watch.NewFake()
+	defer podsWatcher.Stop()
+
 	clientset := testclient.NewSimpleClientset()
 	clientset.PrependWatchReactor("pods", k8stest.DefaultWatchReactor(podsWatcher, nil))
 	clientset.PrependWatchReactor("deployments", k8stest.DefaultWatchReactor(deploymentsWatcher, nil))
 
 	go func() {
-		defer podsWatcher.Stop()
-		defer deploymentsWatcher.Stop()
+		defer cancel()
 
 		deployment := &appsv1.Deployment{ObjectMeta: metav1.ObjectMeta{Name: "mydeployment", Namespace: "default"}}
 		deploymentsWatcher.Add(deployment)
@@ -99,8 +101,6 @@ func TestWatcherWithPodWatcher(t *testing.T) {
 			podsWatcher.Add(pod)
 			time.Sleep(time.Millisecond * 250)
 		}
-
-		cancel()
 	}()
 
 	var buf bytes.Buffer