Keptn - Kubernetes

Keptn Tasks running on a Kubernetes cluster can be triggered for workloads and applications that are deployed outside of Kubernetes. For example, Keptn could trigger load and performance tests for an application that is deployed on a virtual machine.

To do this:

• Install Keptn on a Kubernetes cluster
• Create a KeptnTaskDefinition
• Create and apply a KeptnTask
• Re-run the KeptnTask

Install Keptn on a Kubernetes cluster

You must set up a Kubernetes cluster and install Keptn on it, but this can be a very lightweight, single-node KinD cluster; see Create local Kubernetes cluster. Keptn only triggers on-demand KeptnTask resources so resource utilization is minimal.

Create a KeptnTaskDefinition

When you have Keptn installed, create a YAML file that defines what you want to execute as a KeptnTaskDefinition resource. See Deployment tasks and the KeptnTaskDefinition reference page for more information.

For example, you might create a test-task-definition.yaml file with the following content:

apiVersion: lifecycle.keptn.sh/v1alpha3
kind: KeptnTaskDefinition
metadata:
  name: helloworldtask
spec:
  retries: 0
  timeout: 30s
  container:
    name: cowsay
    image: rancher/cowsay:latest
    args:
      - 'hello world'

This example uses the container-runtime runner, but you can instead use the deno-runtime or python-runtime runner. See Runners and containers for more information.

Create and apply a KeptnTask

You must manually create the KeptnTask resource. In the standard operating mode, when Keptn is managing workloads, the creation of the KeptnTask resource is automatic.

Moreover, each time you want to execute a KeptnTask, you must manually create a new (and uniquely named) KeptnTask resource.

The KeptnTask resource references the KeptnTaskDefinition that you created above in the spec.taskDefinition field. For example, you might create a test-task.yaml file with the following content:

apiVersion: lifecycle.keptn.sh/v1alpha3
kind: KeptnTask
metadata:
  name: runhelloworld1
spec:
  taskDefinition: helloworldtask
  context:
    appName: "my-app"
    appVersion: "1.0.0"
    objectType: ""
    taskType: ""
    workloadName: "my-workload"
    workloadVersion: "1.0.0"

You can then apply this YAML file with the following command:

kubectl apply -f test-task.yaml -n my-keptn-annotated-namespace

Applying this file causes Keptn to create a Job and a Pod and run the executables defined in the associated KeptnTaskDefinition resource.

Use the following commands to show the current status of the jobs:

kubectl get keptntasks -n my-keptn-annotated-namespace
kubectl get pods -n my-keptn-annotated-namespace

Re-run the KeptnTask

For subsequent KeptnTask runs, the KeptnTask name and version fields must be unique, so copy the KeptnTask yaml file you have and update the metadata.name field.

A standard practice is to just increment the value of the suffix field. For example, you could create a test-task-2.yaml file with the metadata.name field set to runhelloworld2:

apiVersion: lifecycle.keptn.sh/v1alpha3
kind: KeptnTask
metadata:
  name: runhelloworld2
spec:
  taskDefinition: helloworldtask
  context:
    appName: "my-app"
    appVersion: "1.0.1"
    objectType: ""
    taskType: ""
    workloadName: "my-workload"
    workloadVersion: "1.0.1"

You can then apply this file with the following command:

kubectl apply -f test-task-2.yaml -n my-keptn-annotated-namespace