Step 2 - Pipelines

OpenShift Supply Chain

- Thomas Jungbauer Thomas Jungbauer ( Lastmod: 2024-05-08 ) - 2 min read

We will now create the Pipeline and try to trigger it for the first time to verify if our Webhook works as intended.

Goals

The goals of this step are:

  • Create the Pipeline with a first task

  • Update the Github repository, to verify if the Webhook works

  • Verify if the PipelineRun is successful

Create the Pipeline

  1. The Pipeline object is responsible to define the Tasks (steps) that should be executed. Whenever a Pipeline is started a PipelineRun is created that performs each defined Task in the defined order and logs the output. Tasks can run subsequently or in parallel.

    Currently, the Pipeline has one task pull-source-code which is defined as a ClusterTask "git-clone". The purpose is to simply pull the source code to the workspace "shared-data".

    apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: secure-supply-chain (1)
  namespace: ci
spec:
  params: (2)
    - name: REPO_HOST
      type: string
    - name: COMMIT_SHA
      type: string
    - name: TLSVERIFY
      type: string
    - name: BUILD_EXTRA_ARGS
      type: string
    - name: IMAGE_REPO
      type: string
    - name: IMAGE_TAG
      type: string
    - name: GIT_REF
      type: string
    - name: COMMIT_DATE
      type: string
    - name: COMMIT_AUTHOR
      type: string
    - name: COMMIT_MESSAGE
      type: string
    - name: GIT_REPO
      type: string
  tasks: (3)
    - name: pull-source-code (4)
      params:
        - name: url (5)
          value: $(params.GIT_REPO)
        - name: revision
          value: $(params.GIT_REF)
        - name: deleteExisting
          value: 'true'
      taskRef: (6)
        kind: ClusterTask
        name: git-clone
      workspaces: (7)
        - name: output
          workspace: shared-data
  workspaces: (8)
  - name: shared-data
    1Name of the Pipeline as referenced in the TriggerTemplate.
    2List of Parameters, hopefully, injected by the EventListener.
    3List of Tasks that will be executed.
    4Name of the Task.
    5Parameters used in this Task.
    6The Reference to the task. Here a ClusterTask named "git-clone" is used.
    7Workspace that shall be used in this Task.
    8Workspaces available in this Pipeline.

    The initial Pipeline will now look like the following (Go to: Pipelines > Pipelines > secure-supply-chain)

Initial Pipeline
Figure 1. Initial Pipeline

Our first Run

Now it is time to update something in our Git Repository and verify if everything can be executed successfully.

To update, it is enough to simply add a space in the README.md file and push it to Git.

If the Webhook works as expected, Git will notify our EventListener, which will then trigger the Pipeline. A PipelineRun is created, that executes all Tasks that are defined in the Pipeline (currently just 1)

You can monitor the progress of the PipelineRun:

PipelineRun
Figure 2. PipelineRun Overview

On the Details-page you can see which step is currently executed:

PipelineRun Details
Figure 3. PipelineRun Details

Eventually, the PipelineRun finishes successfully.

PipelineRun Finished
Figure 4. PipelineRun Finished

You can analyze the Logs in case of an Error or to get more details of a certain Task:

Task Logs
Figure 5. Task Logs

Summary

We have now created our first Pipeline and tested the GitHub Webhook. Whenever we push changes to the code, Git will notify the EventListener which will trigger the Pipeline with all required Parameters.

A PipelineRun is generated and is executing the defined Tasks. Currently, not much is done, expect cloning the Git repository.

In the next steps, we will evolve our Pipeline to perform security checks and sign our image.

See Also:

  • Introducing AdminNetworkPolicies –

    Classic Kubernetes/OpenShift offer a feature called NetworkPolicy that allows users to control the traffic to and from their assigned Namespace. NetworkPolicies are designed to give project owners or tenants the ability to protect their own namespace. Sometimes, however, I worked with customers where the cluster administrators or a dedicated (network) team need to enforce these policies. Since the NetworkPolicy API is namespace-scoped, it is not possible to enforce policies across namespaces. The only solution was to create custom (project) admin and edit roles, and remove the ability of creating, modifying or deleting NetworkPolicy objects. Technically, this is possible and easily done. But shifts the whole network security to cluster administrators. Luckily, this is where AdminNetworkPolicy (ANP) and BaselineAdminNetworkPolicy (BANP) comes into play.

  • Using Kustomize to post render a Helm Chart –

    Lately I came across several issues where a given Helm Chart must be modified after it has been rendered by Argo CD. Argo CD does a helm template to render a Chart. Sometimes, especially when you work with Subcharts or when a specific setting is not yet supported by the Chart, you need to modify it later …​ you need to post-render the Chart. In this very short article, I would like to demonstrate this on a real-live example I had to do. I would like to inject annotations to a Route objects, so that the certificate can be injected. This is done by the cert-utils operator. For the post-rendering the Argo CD repo pod will be extended with a sidecar container, that is watching for the repos and patches them if required.

  • Managing Certificates using GitOps approach –

    The article SSL Certificate Management for OpenShift on AWS explains how to use the Cert-Manager Operator to request and install a new SSL Certificate. This time, I would like to leverage the GitOps approach using the Helm Chart cert-manager I have prepared to deploy the Operator and order new Certificates. I will use an ACME Letsencrypt issuer with a DNS challenge. My domain is hosted at AWS Route 53. However, any other integration can be easily used.

  • Update Cluster Version using GitOps approach –

    During a GitOps journey at one point, the question arises, how to update a cluster? Nowadays it is very easy to update a cluster using CLI or WebUI, so why bother with GitOps in that case? The reason is simple: Using GitOps you can be sure that all clusters are updated to the correct, required version and the version of each cluster is also managed in Git. All you need is the channel you want to use and the desired cluster version. Optionally, you can define the exact image SHA. This might be required when you are operating in a restricted environment.

  • Multiple Sources for Applications in Argo CD –

    Argo CD or OpenShift GitOps uses Applications or ApplicationSets to define the relationship between a source (Git) and a cluster. Typically, this is a 1:1 link, which means one Application is using one source to compare the cluster status. This can be a limitation. For example, if you are working with Helm Charts and a Helm repository, you do not want to re-build (or re-release) the whole chart just because you made a small change in the values file that is packaged into the repository. You want to separate the configuration of the chart with the Helm package. The most common scenarios for multiple sources are (see: Argo CD documentation): Your organization wants to use an external/public Helm chart You want to override the Helm values with your own local values You don’t want to clone the Helm chart locally as well because that would lead to duplication and you would need to monitor it manually for upstream changes. This small article describes three different ways with a working example and tries to cover the advantages and disadvantages of each of them. They might be opinionated but some of them proved to be easier to use and manage.

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