Merge pull request #238 from crimsonfaith91/patch-3

Running End-to-end Tests on Remote Clusters

Author: droot

e2e.md

@@ -0,0 +1,63 @@
+**Running End-to-end Tests on Remote Clusters**
+
+This article outlines steps to run e2e tests on remote clusters for controllers created using `kubebuilder`. For example, after developing a database controller, the developer may want to run some e2e tests on a GKE cluster to verify the controller is working as expected. Currently, `kubebuilder` does not provide a template for running the e2e tests. This article serves to address this deficit.
+
+The steps are as follow:
+1.  Create a test file named `<some-file-name>_test.go` populated with template below (referring [this](https://github.com/foxish/application/blob/master/e2e/main_test.go)):
+```
+import (
+    "k8s.io/client-go/tools/clientcmd"
+    clientset "k8s.io/redis-operator/pkg/client/clientset/versioned/typed/<some-group>/<some-version>"
+    ......
+)
+
+// Specify kubeconfig file 
+func getClientConfig() (*rest.Config, error) {
+    return clientcmd.BuildConfigFromFlags("", path.Join(os.Getenv("HOME"), "<file-path>"))
+}
+
+// Set up test environment
+var _ = Describe("<some-controller-name> should work", func() {
+    config, err := getClientConfig()
+    if err != nil {
+        ......
+    }
+
+    // Construct kubernetes client
+    k8sClient, err := kubernetes.NewForConfig(config)
+    if err != nil {
+        ......
+    }
+
+    // Construct controller client
+    client, err := clientset.NewForConfig(config)
+    if err != nil {
+        ......
+    }
+
+    BeforeEach(func() {
+        // Create environment-specific resources such as controller image StatefulSet,
+        // CRDs etc. Note: refer "install.yaml" created via "kubebuilder create config"
+        // command to have an idea of what resources to be created.
+        ......
+    })
+
+    AfterEach(func() {
+        // Delete all test-specific resources
+        ......		
+
+        // Delete all environment-specific resources
+        ......
+    })
+
+    // Declare a list of testing specifications with corresponding test functions
+    // Note: test-specific resources are normally created within the test functions
+    It("should do something", func() {
+        testDoSomething(k8sClient, roClient)
+    })
+    
+    ......
+```
+2.  Write some controller-specific e2e tests
+3.  Build controller image and upload it to an image storage website such as [gcr.io](https://cloud.google.com/container-registry/)
+4.  `go test <path-to-test-file>`