Getting Started with Pipelines

This tutorial shows you how to:

• Create two Tasks.
• Create a Pipeline containing your Tasks.
• Use PipelineRun to instantiate and run the Pipeline containing your Tasks.

This guide uses a local cluster with minikube.

Prerequisites

1. Complete the Getting started with Tasks tutorial. Do not clean up your resources, skip the last section.

2. Install tkn, the Tekton CLI.

Create and run a second Task

You already have a “Hello World!” Task. To create a second “Goodbye!” Task:

1. Create a new file named goodbye-world.yaml and add the following content:

   apiVersion: tekton.dev/v1
   kind: Task
   metadata:
     name: goodbye
   spec:
     params:
     - name: username
       type: string
     steps:
       - name: goodbye
         image: ubuntu
         script: |
           #!/bin/bash
           echo "Goodbye $(params.username)!"        
   

   This Task takes one parameter, username. Whenever this Task is used a value for that parameter must be passed to the Task.

2. Apply the Task file:

   kubectl apply --filename goodbye-world.yaml
   

When a Task is part of a Pipeline, Tekton creates a TaskRun object for every task in the Pipeline.

Create and run a Pipeline

A Pipeline defines an ordered series of Tasks arranged in a specific execution order as part of the CI/CD workflow.

In this section you are going to create your first Pipeline, that will include both the “Hello World!” and “Goodbye!” Tasks.

1. Create a new file named hello-goodbye-pipeline.yaml and add the following content:

   apiVersion: tekton.dev/v1
   kind: Pipeline
   metadata:
     name: hello-goodbye
   spec:
     params:
     - name: username
       type: string
     tasks:
       - name: hello
         taskRef:
           name: hello
       - name: goodbye
         runAfter:
           - hello
         taskRef:
           name: goodbye
         params:
         - name: username
           value: $(params.username)
   

   The Pipeline defines the parameter username, which is then passed to the goodbye Task.

2. Apply the Pipeline configuration to your cluster:

   kubectl apply --filename hello-goodbye-pipeline.yaml
   

3. A PipelineRun, represented in the API as an object of kind PipelineRun, sets the value for the parameters and executes a Pipeline. To create PipelineRun, create a new file named hello-goodbye-pipeline-run.yaml with the following:

   apiVersion: tekton.dev/v1
   kind: PipelineRun
   metadata:
     name: hello-goodbye-run
   spec:
     pipelineRef:
       name: hello-goodbye
     params:
     - name: username
       value: "Tekton"
   

   This sets the actual value for the username parameter: "Tekton".

4. Start the Pipeline by applying the PipelineRun configuration to your cluster:

   kubectl apply --filename hello-goodbye-pipeline-run.yaml
   

   You see the following output:

   pipelinerun.tekton.dev/hello-goodbye-run created
   

   Tekton now starts running the Pipeline.

5. To see the logs of the PipelineRun, use the following command:

   tkn pipelinerun logs hello-goodbye-run -f -n default
   

   The output shows both Tasks completed successfully:

   [hello : echo] Hello World!
   
   [goodbye : goodbye] Goodbye Tekton!
   

Cleanup

To learn about Tekton Triggers, 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 qemu2 ...
💀  Removed all traces of the "minikube" cluster.

Further reading

We recommend that you complete Getting started with Triggers.

For more complex examples check:

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