Chore: add example for env patch and fix e2e flaky (#2462)

docs/examples/advanced-cue/env-patch.yaml

@@ -0,0 +1,24 @@
+apiVersion: core.oam.dev/v1beta1
+kind: Application
+metadata:
+  name: env-patch
+spec:
+  components:
+    - name: express-server
+      properties:
+        cmd:
+          - node
+          - server.js
+        image: oamdev/testapp:v1
+        port: 8080
+        env:
+          - name: myenv1
+            value: myvalue1
+          - name: myenv2
+            value: myvalue2
+      traits:
+        - type: env
+          properties:
+            env:
+              myenv1: myvalue-trait-patched
+      type: webservice

test/e2e-test/app_revision_clean_up_test.go

@@ -78,7 +78,10 @@ var _ = Describe("Test application controller clean up appRevision", func() {
 		appName := "app-1"
 		appKey := types.NamespacedName{Namespace: namespace, Name: appName}
 		app := getApp(appName, namespace, "normal-worker")
-		Expect(k8sClient.Create(ctx, app)).Should(BeNil())
+		Eventually(func() error {
+			err := k8sClient.Create(ctx, app)
+			return err
+		}, 15*time.Second, 300*time.Millisecond).Should(BeNil())
 		checkApp := new(v1beta1.Application)
 		for i := 0; i < appRevisionLimit; i++ {
 			Eventually(func() error {