From b880127e726693f4d370a20b15a9a1d47317cc61 Mon Sep 17 00:00:00 2001
From: Rob Watson <rob@netflux.io>
Date: Tue, 21 Jun 2022 20:32:32 +0200
Subject: [PATCH] watcher: implement RetryWatcher

---
 go.mod               |  1 +
 go.sum               |  1 +
 logs/watcher.go      | 20 +++++++++++++-------
 logs/watcher_test.go |  1 +
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/go.mod b/go.mod
index 5c2ec08..815ce66 100644
--- a/go.mod
+++ b/go.mod
@@ -23,6 +23,7 @@ require (
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/gnostic v0.5.7-v3refs // indirect
+	github.com/google/go-cmp v0.5.5 // indirect
 	github.com/google/gofuzz v1.1.0 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
diff --git a/go.sum b/go.sum
index 097d7e1..f596b58 100644
--- a/go.sum
+++ b/go.sum
@@ -169,6 +169,7 @@ github.com/google/pprof v0.0.0-20201203190320-1bf35d6f28c2/go.mod h1:kpwsk12EmLe
 github.com/google/pprof v0.0.0-20210122040257-d980be63207e/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/pprof v0.0.0-20210226084205-cbba55b83ad5/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/google/uuid v1.1.2 h1:EVhdT+1Kseyi1/pUmXKaFxYsDNy9RQYkMWRH68J/W7Y=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
diff --git a/logs/watcher.go b/logs/watcher.go
index 3fb3253..c959caa 100644
--- a/logs/watcher.go
+++ b/logs/watcher.go
@@ -19,6 +19,8 @@ import (
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/cache"
+	toolswatch "k8s.io/client-go/tools/watch"
 )
 
 // KubernetesClient provides both typed and untyped interfaces to the
@@ -101,17 +103,21 @@ func (w *Watcher) Watch(ctx context.Context) error {
 		return err
 	}
 
-	opts := metav1.ListOptions{Watch: true, FieldSelector: "metadata.name=" + w.params.Name}
-	watcher, err := w.client.Untyped.Resource(resourceID).Namespace(ns).Watch(ctx, opts)
+	watchFunc := func(_ metav1.ListOptions) (watch.Interface, error) {
+		return w.client.Untyped.
+			Resource(resourceID).
+			Namespace(ns).
+			Watch(ctx, metav1.ListOptions{Watch: true, FieldSelector: "metadata.name=" + w.params.Name})
+	}
+	retryWatcher, err := toolswatch.NewRetryWatcher("1", &cache.ListWatch{WatchFunc: watchFunc})
 	if err != nil {
 		return err
 	}
-	defer watcher.Stop()
 
 	ticker := time.NewTicker(time.Second)
 	defer ticker.Stop()
 
-	resultChan := watcher.ResultChan()
+	resultChan := retryWatcher.ResultChan()
 	for {
 		select {
 		case evt, ok := <-resultChan:
@@ -135,7 +141,7 @@ func (w *Watcher) Watch(ctx context.Context) error {
 			case watch.Deleted:
 				w.unwatchResource()
 			case watch.Error:
-				err := evt.Object.(error)
+				err := evt.Object.(*metav1.Status)
 				// TODO: remove panic and handle error
 				panic(err)
 			}
@@ -167,7 +173,7 @@ func (w *Watcher) watchResource(ctx context.Context, resourceUID types.UID, podS
 
 	w.unwatchResource()
 
-	w.logger.Println("[Watcher] add podWatcher")
+	w.logger.Printf("[Watcher] add podWatcher, resourceUID = %s", resourceUID)
 
 	w.resourceUID = resourceUID
 	w.podSelector = podSelector
@@ -189,7 +195,7 @@ func (w *Watcher) watchResource(ctx context.Context, resourceUID types.UID, podS
 
 func (w *Watcher) unwatchResource() {
 	if w.podWatcher != nil {
-		w.logger.Println("[Watcher] remove podWatcher")
+		w.logger.Printf("[Watcher] remove podWatcher, resourceUID = %s", w.resourceUID)
 		w.podWatcher.Close()
 		w.podWatcher = nil
 	}
diff --git a/logs/watcher_test.go b/logs/watcher_test.go
index afa90c4..6da08c6 100644
--- a/logs/watcher_test.go
+++ b/logs/watcher_test.go
@@ -47,6 +47,7 @@ func buildDeployment(t *testing.T, name string) *unstructured.Unstructured {
 	deployment.SetName("mydeployment")
 	deployment.SetNamespace("default")
 	deployment.SetUID(types.UID("foo"))
+	deployment.SetResourceVersion("1")
 	require.NoError(t, unstructured.SetNestedField(deployment.Object, map[string]any{"app": "myapp"}, "spec", "selector", "matchLabels"))
 	return deployment
 }