Kubernetes Event Triggers

Testkube allows you to automate running test workflows by defining triggers on certain events for various Kubernetes resources.

What is a Testkube Event Trigger?

In generic terms, a Trigger defines an action which will be executed for a given execution when a certain event on a specific resource occurs. For example, we could define a TestTrigger which runs a Test when a ConfigMap gets modified.

In Testkube, Event Triggers allow you to trigger the execution of a Workflow based on Kubernetes Events - for example when a Deployment is updated or an Ingress gets deleted.

You can currently create/manage Event Triggers in the Testkube Dashboard or by interacting with corresponding Trigger custom resources via kubectl.

Creating Test Triggers in the Testkube Dashboard

Click on the lightening bolt icon on the left of the Testkube Dashboard to open the dialog to create test triggers. Any current test triggers will be listed and the Create a new trigger button is at the top right of the screen.

The Create a new trigger dialog opens, where one can configure the condition for the trigger:

After clicking Next, then one can configure the action to execute on the trigger and then click Create to create it.

Custom Resource Definition Model

Triggers are ultimately defined as Customer Resources in your cluster - TestTrigger Reference

Selectors

Triggers use Selectors to specify which events to listen for.

The resourceSelector and testSelector fields support selecting resources either by name or using the Kubernetes Label Selector.

Each selector should specify the namespace of the object, otherwise the namespace defaults to testkube.

selector := resourceSelector | testSelector

Name Selector

Name selectors are used when we want to select a specific resource in a specific namespace.

selector:
  name: Kubernetes object name
  nameRegex: Kubernetes object name regex (for example, "testworkflow.*")
  namespace: Kubernetes object namespace (default is **testkube**)

Label Selector

Label selectors are used when we want to select a group of resources in a specific namespace.

selector:
  namespace: Kubernetes object namespace (default is **testkube**)
  labelSelector:
    matchLabels: map of key-value pairs
    matchExpressions:
      - key: label name
        operator: [In | NotIn | Exists | DoesNotExist
        values: list of values

Resource Conditions

Resource Conditions allows triggers to be defined based on the status conditions for a specific resource.

conditionSpec:
  timeout: Duration in seconds the test trigger waits for conditions, until its stopped.
  delay: Duration in seconds the test trigger waits between condition checks.
  conditions:
    - type: test trigger condition type
      status: test trigger condition status, supported values - True, False, Unknown
      reason: test trigger condition reason
      ttl: test trigger condition ttl

Resource Probes

Resource Probes allows triggers to be defined based on the probe status.

probeSpec:
  timeout: Duration in seconds the test trigger waits for probes, until its stopped.
  delay: Duration in seconds the test trigger waits between probes.
  probes:
    - scheme: test trigger condition probe scheme to connect to host, default is http
      host: test trigger condition probe host, default is pod ip or service name
      path: test trigger condition probe path to check, default is /
      port: test trigger condition probe port to connect
      headers: test trigger condition probe headers to submit

Supported Values

• Resource - pod, deployment, statefulset, daemonset, service, ingress, event, configmap
• Action - run
• Event - created, modified, deleted
• Cause (can be used instead of Event)
  • For deployments - deployment-scale-update, deployment-image-update, deployment-env-update, deployment-containers-modified
  • For Testkube events - event-start-test, event-end-test-success, event-end-test-failed, event-end-test-aborted, event-end-test-timeout, event-start-testsuite, event-end-testsuite-success, event-end-testsuite-failed, event-end-testsuite-aborted, event-end-testsuite-timeout, event-queue-testworkflow, event-start-testworkflow, event-end-testworkflow-success, event-end-testworkflow-failed, event-end-testworkflow-aborted, event-created, event-updated, event-deleted
• Execution - test, testsuite, testworkflow
• ConcurrencyPolicy - allow, forbid, replace

info

Events and values related to Tests and Test Suites have been deprecated and will be removed - Read More

Examples

On Deployment Update

Here is an example for a Test Trigger default/testtrigger-example which runs the TestSuite frontend/sanity-test when a deployment containing the label testkube.io/tier: backend gets modified and also has the conditions Progressing: True: NewReplicaSetAvailable and Available: True.

apiVersion: tests.testkube.io/v1
kind: TestTrigger
metadata:
  name: testtrigger-example
  namespace: default
spec:
  resource: deployment
  resourceSelector:
    labelSelector:
      matchLabels:
        testkube.io/tier: backend
  event: modified
  conditionSpec:
    timeout: 100
    delay: 2
    conditions:
      - type: Progressing
        status: "True"
        reason: "NewReplicaSetAvailable"
        ttl: 60
      - type: Available
        status: "True"
  probeSpec:
    timeout: 50
    delay: 1
    probes:
      - scheme: http
        host: testkube-api-server
        path: /health
        port: 8088
        headers:
          X-Token: "12345"
      - host: testkube-dashboard
        port: 8080
  action: run
  execution: testworkflow
  concurrencyPolicy: allow
  testSelector:
    name: sanity-test
    namespace: frontend
  disabled: false

On Testkube Cluster Event

You can define Test Trigger for Testkube cluster events. In below example, if TestWorkflow k6-executor-smoke is completed succesfully, then we run TestWorkflow postman-smoke-tests

apiVersion: tests.testkube.io/v1
kind: TestTrigger
metadata:
  name: testtrigger-event
  namespace: testkube
spec:
  resource: event
  resourceSelector:
    name: k6-smoke-test
  event: event-end-test-success
  action: run
  execution: testworkflow
  testSelector:
    name: postman-smoke-tests
    namespace: testkube

Disabling Test Triggers

Disabling test triggers can be helpful to test your configuration during the development. Testkube lets you disable them via the API or modifying the CRD directly specifying disabled field value as true.

By default, test triggers are enabled on creation.

Architecture

Testkube uses Informers to watch Kubernetes resources and register handlers on certain actions on the watched Kubernetes resources.

Informers are a reliable, scalable and fault-tolerant Kubernetes concept where each informer registers handlers with the Kubernetes API and gets notified by Kubernetes on each event on the watched resources.

API

Testkube exposes CRUD operations on test triggers in the REST API. Check out the OpenAPI docs for more info.

Injected Environment Variables

The following environment variables are automatically injected into each triggered test pod:

• WATCHER_EVENT_RESOURCE: resource type
• WATCHER_EVENT_NAME: resource name
• WATCHER_EVENT_NAMESPACE: resource namespace
• WATCHER_EVENT_EVENT_TYPE: event type