Getting started with Tasks

This tutorial shows you how to

1. Create a Kubernetes cluster with minikube.
2. Install Tekton pipelines.
3. Create a Task.
4. Use TaskRun to instantiate and run the Task.

Prerequisites

1. Install minikube. You only have to complete the step 1, “Installation”.

2. Install kubectl.

Create a Kubernetes cluster

Create a cluster

minikube start --kubernetes-version v1.25.14

The process takes a few seconds, you see an output similar to the following, depending on the minikube driver that you are using:

😄  minikube v1.25.1
✨  Using the docker driver based on existing profile
👍  Starting control plane node minikube in cluster minikube
🚜  Pulling base image ...
🔄  Restarting existing docker container for "minikube" ...
🐳  Preparing Kubernetes v1.23.1 on Docker 20.10.12 ...
    ▪ kubelet.housekeeping-interval=5m
    ▪ Generating certificates and keys ...
    ▪ Booting up control plane ...
    ▪ Configuring RBAC rules ...
🔎  Verifying Kubernetes components...
    ▪ Using image gcr.io/k8s-minikube/storage-provisioner:v5
🌟  Enabled addons: storage-provisioner, default-storageclass
🏄  Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default

You can check that the cluster was successfully created with kubectl:

kubectl cluster-info

The output confirms that Kubernetes is running:

Kubernetes control plane is running at https://127.0.0.1:39509
CoreDNS is running at
https://127.0.0.1:39509/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

Install Tekton Pipelines

1. To install the latest version of Tekton Pipelines, use kubectl:

   kubectl apply --filename \
   https://storage.googleapis.com/tekton-releases/pipeline/latest/release.yaml
   

2. Monitor the installation:

   kubectl get pods --namespace tekton-pipelines --watch
   

   When both tekton-pipelines-controller and tekton-pipelines-webhook show 1/1 under the READY column, you are ready to continue. For example:

   NAME                                           READY   STATUS              RESTARTS   AGE
   tekton-pipelines-controller-6d989cc968-j57cs   0/1     Pending             0          3s
   tekton-pipelines-webhook-69744499d9-t58s5      0/1     ContainerCreating   0          3s
   tekton-pipelines-controller-6d989cc968-j57cs   0/1     ContainerCreating   0          3s
   tekton-pipelines-controller-6d989cc968-j57cs   0/1     Running             0          5s
   tekton-pipelines-webhook-69744499d9-t58s5      0/1     Running             0          6s
   tekton-pipelines-controller-6d989cc968-j57cs   1/1     Running             0          10s
   tekton-pipelines-webhook-69744499d9-t58s5      1/1     Running             0          20s
   

   Hit Ctrl + C to stop monitoring.

Create and run a basic Task

A Task, represented in the API as an object of kind Task, defines a series of Steps that run sequentially to perform logic that the Task requires. Every Task runs as a pod on the Kubernetes cluster, with each step running in its own container.

1. To create a Task, open your favorite editor and create a file named hello-world.yaml with the following content:

   apiVersion: tekton.dev/v1beta1
   kind: Task
   metadata:
     name: hello
   spec:
     steps:
       - name: echo
         image: alpine
         script: |
           #!/bin/sh
           echo "Hello World"        
   

2. Apply the changes your cluster:

   kubectl apply --filename hello-world.yaml
   

   The output confirms that the Task was completed successfully.

   task.tekton.dev/hello created
   

3. A TaskRun object instantiates and executes this Task. Create another file named hello-world-run.yaml with the following content:

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

4. Apply the changes to your cluster to launch the Task:

   kubectl apply --filename hello-world-run.yaml
   

5. Verify that everything worked correctly:

   kubectl get taskrun hello-task-run
   

   The output of this command shows the status of the Task

    NAME                    SUCCEEDED    REASON       STARTTIME   COMPLETIONTIME
    hello-task-run          True         Succeeded    22h         22h
   

   The value True under SUCCEEDED confirms that TaskRun completed with no errors.

6. Take a look at the logs:

   kubectl logs --selector=tekton.dev/taskRun=hello-task-run
   

   The output displays the message:

   Hello World
   

Cleanup

To learn about Tekton Pipelines, skip this section and proceed to the next tutorial.

To delete the cluster that you created for this guide run:

minikube delete

The output confirms that the cluster was deleted:

🔥  Deleting "minikube" in docker ...
🔥  Deleting container "minikube" ...
🔥  Removing /home/user/.minikube/machines/minikube ...
💀  Removed all traces of the "minikube" cluster.

Further Reading:

We recommend that you complete Getting started with Pipelines.

For more complex examples see:

• Clone a git repository with Tekton.
• Build and push a container image with Tekton.