Introduction To Tekton Tasks And TaskRuns

3 min readApr 6, 2021

Tekton is an OpenSource project under CD foundation which provides a framework for creating CI/CD systems in cloud native way. In simple terms, you can define your entire CI/CD pipeline as Kubernetes resources.

Tekton Pipelines have its core reusable component known as Task which can be easily shared. Before understanding Task let’s understand what Steps are

Steps is a reference to container image
Runs command or script in a container on specific input and produces specific output
To add Steps to a Task you define a steps field (required) containing a list of desired Steps
The order in which the Steps appear in this list is the order in which they will execute.
Kubernetes container spec
* Env vars
* Volumes
* Config maps
* Secrets

Next let’s look what a Task is and how it is defined and structured

Collection of steps to be executed in a specific order
Task defines a unit of work to be executed
A Task executes as a Pod on a cluster
The steps defined in the container run in the task pod
Task is independent of Pipeline and can be executed

Now let’s create a simple hello-world Task which echos hello-world

apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: echo-hello-world
spec:
  steps:
    - name: echo
      image: ubuntu
      command:
        - echo
      args:
        - "hello world"

To install a Tekton resoure first tekton-pipelines should be installed. You can find installation docs here

Let’s install this task using kubectl

╰─ kubectl apply -f hello-task.yaml                                                                                                                           
task.tekton.dev/echo-hello-world configured

You can also list the task using tkn list command. To know more about tkn see here

╰─ tkn task ls                    
NAME               DESCRIPTION              AGE
buildah            Buildah task builds...   2 days ago
echo-hello-world                            2 days ago

To run this Task we can either create a Taskrun or we can use tkn start command to start the task. First let’s run this task using a TaskRun.

Before that let’s knkow what a TaskRun is:

TaskRun allows to instantiate and execute a Task with specific inputs and execution parameters
A Task specifies one or more Steps that execute container images and each container image performs a specific piece of build work.
TaskRun executes the Steps in the Task in the order they are specified until all Steps have executed successfully or a failure occurs.

Manifest for TaskRun for echo-hello-world-run will look as follows:

apiVersion: tekton.dev/v1beta1
kind: TaskRun
metadata:
  name: echo-hello-world-run
spec:
  taskRef:
    name: echo-hello-world

Let’s apply the TaskRun using kubectl

╰─ k apply -f hello-task-run.yaml
taskrun.tekton.dev/echo-hello-world-run created

You can list the TaskRun using tkn

╰─ tkn taskrun list                                  
NAME                   STARTED         DURATION    STATUS
echo-hello-world-run   5 minutes ago   7 seconds   Succeeded

You can also see the logs of the TaskRun using tkn and you will see the desired output

╰─ tkn taskrun logs echo-hello-world-run 
[echo] hello world

You can find more about Tekton Tasks here

For any queries please reach out to me on Github (PuneetPunamiya)

Introduction To Tekton Tasks And TaskRuns

Written by Puneet Punamiya