# Tips and Tricks
This document contains some tips and gotchas that can be helpful when writing tests.
# Loading Built Images Into KIND
When KIND clusters are started, you may want to load an image that has not been pushed into the registry. To do this, you can use the
kindContainers setting on your
docker build -t myimage .
And then in the TestSuite, set:
apiVersion: kudo.dev/v1alpha1 kind: TestSuite startKIND: true kindContainers: - myimage
When the KIND cluster is launched, the image will be loaded into it.
# Kubernetes Events
Kubernetes events are regular Kubernetes objects and can be asserted on just like any other object:
apiVersion: v1 kind: Event reason: Started source: component: kubelet involvedObject: apiVersion: v1 kind: Pod name: my-pod
# Custom Resource Definitions
New Custom Resource Definitions are not immediately available for use in the Kubernetes API until the Kubernetes API has acknowledged them.
If a Custom Resource Definition is being defined inside of a test step, be sure to to wait for the
CustomResourceDefinition object to appear.
For example, given this Custom Resource Definition in
apiVersion: apiextensions.k8s.io/v1beta1 kind: CustomResourceDefinition metadata: name: mycrds.mycrd.k8s.io spec: group: mycrd.k8s.io version: v1alpha1 names: kind: MyCRD listKind: MyCRDList plural: mycrds singular: mycrd scope: Namespaced
Create the following assert
apiVersion: apiextensions.k8s.io/v1beta1 kind: CustomResourceDefinition metadata: name: mycrds.mycrd.k8s.io status: acceptedNames: kind: MyCRD listKind: MyCRDList plural: mycrds singular: mycrd storedVersions: - v1alpha1
And then the CRD can be used in subsequent steps,
apiVersion: mycrd.k8s.io/v1alpha1 kind: MyCRD spec: test: test
Note that CRDs created via the
crdDir test suite configuration are available for use immediately and do not require an assert like this.
# Helm testing
You can test a Helm chart by installing it in either a test step or your test suite:
apiVersion: kudo.dev/v1alpha1 kind: TestSuite commands: - command: kubectl create serviceaccount -n kube-system tiller ignoreFailure: true - command: kubectl create clusterrolebinding tiller --clusterrole=cluster-admin --serviceaccount=kube-system:tiller ignoreFailure: true - command: helm init --wait --service-account tiller - command: helm delete --purge memcached ignoreFailure: true - command: helm install --replace --namespace memcached --name nginx stable/memcached testDirs: - ./test/integration startKIND: true kindNodeCache: true
# Image caching in kind
By default, kind (opens new window) does not persist its containerd directory, meaning that on every test run you will have to download all of the images defined in the tests. However, the kudo test harness supports creating a named Docker volume for each node specified in the kind configuration (or the default node if no nodes or configuration are specified) that will be used for each test run:
apiVersion: kudo.dev/v1alpha1 kind: TestSuite startKIND: true kindNodeCache: true testDirs: - ./test/integration
The first time you run the tests, the nodes will download the images, but subsequent runs will used the cached images.