Powering CI/CD with OpenShift Pipelines
Table of Contents
Introduction #
In the rapidly evolving world of software development, Continuous Integration/Continuous Deployment (CI/CD) has become a cornerstone practice. It ensures swift delivery of features and fixes, while maintaining quality and stability. Among the various tools available for CI/CD, one stands out for its robustness and integration capabilities – OpenShift Pipelines.
In this blog post, we’ll delve into OpenShift Pipelines, compare it with other prominent CI/CD tools, and showcase its integrations with OpenShift’s many plugins. To top it all off, we’ll walk through a step-by-step guide on deploying a Python application using OpenShift Pipelines.
Understanding OpenShift Pipelines #
OpenShift Pipelines is a cloud-native, continuous integration and continuous delivery (CI/CD) solution built for Kubernetes environments. It’s based on the Tekton project, an open-source framework for creating CI/CD systems that run entirely on Kubernetes.
Tekton introduces several Kubernetes custom resources (CRs) for declaring CI/CD pipelines that are portable across Kubernetes distributions. OpenShift Pipelines leverages these resources to provide a seamless, developer-friendly experience. It allows you to define and run pipelines as code, which can be version controlled and treated just like application code. OpenShift Pipelines utilizes Tekton’s building blocks to automate deployments across multiple platforms, abstracting away the underlying implementation details.
!IMAGE-HERE! (A screenshot of an OpenShift Pipeline in action)
How Pipelines Run #
OpenShift Pipelines is a serverless CI/CD system that runs pipelines with all the required dependencies in isolated containers. It is designed for decentralized teams working on a microservice-based architecture and uses standard CI/CD pipeline definitions that are easy to extend and integrate with existing Kubernetes tools. This allows the system to scale on-demand. It also supports building images with Kubernetes tools such as Source-to-Image (S2I), Buildah, Buildpacks, and Kaniko that are portable across any Kubernetes platform.
!IMAGE-HERE! A diagram showing how OpenShift Pipelines work.
Tekton’s CRs and How They Work #
OpenShift Pipelines, or Tekton, consists of several underlying custom resources (CRs). These provide Tekton’s functionality in a k8s-native manner. Below are some of the core CRs.
Tasks #
At the heart of OpenShift Pipelines are Tasks, the building blocks of a pipeline. A Task consists of sequentially executed steps and can run individually or as part of a pipeline. Tasks are reusable and can be used in multiple pipelines. Every Task runs as a pod, and each Step within the Task runs as a container within that pod, allowing them to share the same volumes for caching files, config maps, and secrets.
TaskRun #
A TaskRun is a specific instance of a Task for execution with specific inputs, outputs, and execution parameters on a cluster. It can be invoked on its own or as part of a PipelineRun for each Task in a pipeline. A Task consists of one or more Steps that execute container images, and each container image performs a specific piece of build work. A TaskRun executes the Steps in a Task in the specified order, until all Steps execute successfully or a failure occurs. A TaskRun is automatically created by a PipelineRun for each Task in a Pipeline.
Pipelines #
A Pipeline is a collection of Task resources arranged in a specific order of execution. They are executed to construct complex workflows that automate the build, deployment, and delivery of applications. You can define a CI/CD workflow for your application using pipelines containing one or more tasks.
Comparing OpenShift Pipelines with Other CI/CD Tools #
To understand the value that OpenShift Pipelines brings to the table, let’s compare it with other popular CI/CD tools: GitLab Pipelines, GitHub Actions, and Jenkins.
OpenShift Pipelines vs GitLab Pipelines #
While both tools provide robust CI/CD capabilities, they differ significantly in their design principles and execution environments. GitLab Pipelines is a feature of GitLab and runs on GitLab-run servers, unless you host your own instance of GitLab. On the other hand, OpenShift Pipelines runs directly on your Kubernetes environment, providing more control over resources and execution.
OpenShift Pipelines vs GitHub Actions #
Like GitLab Pipelines, GitHub Actions is deeply integrated into its parent platform, GitHub. This makes it a great option for projects already hosted on GitHub. However, OpenShift Pipelines, with its Kubernetes-native design, offers better scalability and is more adaptable to complex workflows that require fine-grained control over the underlying infrastructure.
OpenShift Pipelines vs Jenkins #
Jenkins is a long-standing, widely used tool in the CI/CD space. It’s known for its flexibility and extensive plugin ecosystem. However, Jenkins isn’t built for Kubernetes, so it can’t leverage the benefits of a cloud-native environment as effectively as OpenShift Pipelines. Moreover, OpenShift Pipelines’ pipeline-as-code approach can be more intuitive than Jenkins’ job-based approach, especially for developers familiar with Infrastructure as Code (IaC).
Integrations #
OpenShift Pipelines integrates seamlessly with other OpenShift components, enhancing its capabilities and your CI/CD workflows.
OpenShift GitOps #
OpenShift GitOps, based on Argo CD, enables you to implement GitOps workflows with OpenShift Pipelines. This means you can use a Git repository as the single source of truth. OpenShift GitOps ensures consistency in applications when you deploy them to different clusters in different environments such as development, staging, and production. It organizes the deployment process around the configuration repositories and makes them the central element. The GitOps workflow pushes an application through development, testing, staging, and production. GitOps either deploys a new application or updates an existing one, so you only need to update the repository; GitOps automates everything else.
OpenShift Virtualization #
OpenShift Serverless #
Deploying a Python Application with OpenShift Pipelines #
Conclusion #
OpenShift Pipelines is a powerful and versatile CI/CD solution that provides a robust, scalable, and serverless environment for automating deployments. Its integration with other OpenShift products like GitOps, Virtualization, and Serverless further enhances its capabilities and makes it a great choice for teams looking for a comprehensive CI/CD solution.