1.2. Red Hat OpenShift Pipelines concepts
Red Hat OpenShift Pipelines provide a set of standard Custom Resource Definitions (CRDs) that act as the building blocks from which you can assemble a CI/CD pipeline for your application.
- Task
- A Task is the smallest configurable unit in a Pipeline. It is essentially a function of inputs and outputs that form the Pipeline build. It can run individually or as a part of a Pipeline. A Pipeline includes one or more Tasks, where each Task consists of one or more Steps. Steps are a series of commands that are sequentially executed by the Task.
- Pipeline
- A Pipeline consists of a series of Tasks that are executed to construct complex workflows that automate the build, deployment, and delivery of applications. It is a collection of PipelineResources, parameters, and one or more Tasks. A Pipeline interacts with the outside world by using PipelineResources, which are added to Tasks as inputs and outputs.
- PipelineRun
- A PipelineRun is the running instance of a Pipeline. A PipelineRun initiates a Pipeline and manages the creation of a TaskRun for each Task being executed in the Pipeline.
- TaskRun
- A TaskRun is automatically created by a PipelineRun for each Task in a Pipeline. It is the result of running an instance of a Task in a Pipeline. It can also be manually created if a Task runs outside of a Pipeline.
- Workspace
- A Workspace is a storage volume that a Task requires at runtime to receive input or provide output. A Task or Pipeline declares the Workspace, and a TaskRun or PipelineRun provides the actual location of the storage volume, which mounts on the declared Workspace. This makes the Task flexible, reusable, and allows the Workspaces to be shared across multiple Tasks.
- Trigger
- A Trigger captures an external event, such as a Git pull request and processes the event payload to extract key pieces of information. This extracted information is then mapped to a set of predefined parameters, which trigger a series of tasks that may involve creation and deployment of Kubernetes resources. You can use Triggers along with Pipelines to create full-fledged CI/CD systems where the execution is defined entirely through Kubernetes resources.
- Condition
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A Condition refers to a validation or check, which is executed before a Task is run in your Pipeline. Conditions are like
ifstatements which perform logical tests, with a return value ofTrueorFalse. A Task is executed if all Conditions returnTrue, but if any of the Conditions fail, the Task and all subsequent Tasks are skipped. You can use Conditions in your Pipeline to create complex workflows covering multiple scenarios.
