Write E2E Tests

You can check the Kubebuilder/v4/test/e2e/utils package, which offers TestContext with rich methods:

• NewTestContext helps define:
  • A temporary folder for testing projects.
  • A temporary controller-manager image.
  • The Kubectl execution method.
  • The CLI executable (whether kubebuilder, operator-sdk, or your extended CLI).

Once defined, you can use TestContext to:

1. Setup the testing environment, e.g.:

   • Clean up the environment and create a temporary directory. See Prepare.
   • Install prerequisite CRDs. See InstallCertManager, InstallPrometheusManager.

2. Validate the plugin behavior, e.g.:

   • Trigger the plugin’s bound subcommands. See Init, CreateAPI.
   • Use PluginUtil to verify scaffolded outputs. See InsertCode, ReplaceInFile, UncommentCode.

3. Ensure the scaffolded output works, e.g.:

   • Execute commands in your Makefile. See Make.
   • Temporarily load an image of the testing controller. See LoadImageToKindCluster.
   • Call Kubectl to validate running resources. See Kubectl.

4. Cleanup temporary resources after testing:

   • Uninstall prerequisite CRDs. See UninstallPrometheusOperManager.
   • Delete the temporary directory. See Destroy.

References:

• operator-sdk e2e tests
• kubebuilder e2e tests

Generate Test Samples

It’s straightforward to view the content of sample projects generated by your plugin.

For example, Kubebuilder generates sample projects based on different plugins to validate the layouts.

You can also use TestContext to generate folders of scaffolded projects from your plugin. The commands are similar to those mentioned in Extending CLI Features and Plugins.

Here’s a general workflow to create a sample project using the go/v4 plugin (kbc is an instance of TestContext):

• To initialize a project:

  By("initializing a project")
  err = kbc.Init(
  	"--plugins", "go/v4",
  	"--project-version", "3",
  	"--domain", kbc.Domain,
  	"--fetch-deps=false",
  )
  ExpectWithOffset(1, err).NotTo(HaveOccurred())
  

• To define API:

  By("creating API definition")
  err = kbc.CreateAPI(
  	"--group", kbc.Group,
  	"--version", kbc.Version,
  	"--kind", kbc.Kind,
  	"--namespaced",
  	"--resource",
  	"--controller",
  	"--make=false",
  )
  ExpectWithOffset(1, err).NotTo(HaveOccurred())
  

• To scaffold webhook configurations:

  By("scaffolding mutating and validating webhooks")
  err = kbc.CreateWebhook(
  	"--group", kbc.Group,
  	"--version", kbc.Version,
  	"--kind", kbc.Kind,
  	"--defaulting",
  	"--programmatic-validation",
  )
  ExpectWithOffset(1, err).NotTo(HaveOccurred())