Chart Tests

A chart contains a number of Kubernetes resources and components that work together. As a chart author, you may want to write some tests that validate that your chart works as expected when it is installed. These tests also help the chart consumer understand what your chart is supposed to do.

A test in a helm chart lives under the templates/ directory and is a job definition that specifies a container with a given command to run. The container should exit successfully (exit 0) for a test to be considered a success. The job definition must contain the helm test hook annotation: helm.sh/hook: test.

Note that until Helm v3, the job definition needed to contain one of these helm test hook annotations: helm.sh/hook: test-success or helm.sh/hook: test-failure. helm.sh/hook: test-success is still accepted as a backwards-compatible alternative to helm.sh/hook: test.

Example tests:

• Validate that your configuration from the values.yaml file was properly injected.
  • Make sure your username and password work correctly
  • Make sure an incorrect username and password does not work
• Assert that your services are up and correctly load balancing
• etc.

You can run the pre-defined tests in Helm on a release using the command helm test <RELEASE_NAME>. For a chart consumer, this is a great way to check that their release of a chart (or application) works as expected.

Example Test

The helm create command will automatically create a number of folders and files. To try the helm test functionality, first create a demo helm chart.

$ helm create demo

You will now be able to see the following structure in your demo helm chart.

demo/
  Chart.yaml
  values.yaml
  charts/
  templates/
  templates/tests/test-connection.yaml

In demo/templates/tests/test-connection.yaml you'll see a test you can try. You can see the helm test pod definition here:

apiVersion: v1
kind: Pod
metadata:
  name: "{{ include "demo.fullname" . }}-test-connection"
  labels:
    {{- include "demo.labels" . | nindent 4 }}
  annotations:
    "helm.sh/hook": test
spec:
  containers:
    - name: wget
      image: busybox
      command: ['wget']
      args: ['{{ include "demo.fullname" . }}:{{ .Values.service.port }}']
  restartPolicy: Never

Steps to Run a Test Suite on a Release

First, install the chart on your cluster to create a release. You may have to wait for all pods to become active; if you test immediately after this install, it is likely to show a transitive failure, and you will want to re-test.

$ helm install demo demo --namespace default
$ helm test demo
NAME: demo
LAST DEPLOYED: Mon Feb 14 20:03:16 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE:     demo-test-connection
Last Started:   Mon Feb 14 20:35:19 2022
Last Completed: Mon Feb 14 20:35:23 2022
Phase:          Succeeded
[...]

Notes

• You can define as many tests as you would like in a single yaml file or spread across several yaml files in the templates/ directory.
• You are welcome to nest your test suite under a tests/ directory like <chart-name>/templates/tests/ for more isolation.
• A test is a Helm hook, so annotations like helm.sh/hook-weight and helm.sh/hook-delete-policy may be used with test resources.