Triggers

A Trigger specifies what happens when the EventListener detects an event. A Trigger specifies a TriggerTemplate, a TriggerBinding, and optionally an Interceptor.

Structure of a Trigger

When creating a Trigger definition you must specify the required fields and can also specify any of the optional fields listed below:

• Required:
  • apiVersion - Specifies the API version; for example triggers.tekton.dev/v1alpha1.
  • kind - Specifies that this resource object is a Trigger object.
  • metadata - Specifies metadata to uniquely identify this Trigger object; for example a name.
  • spec - Specifies the configuration information for this Trigger object, including:
    • [bindings] - (Optional) Specifies a list of field bindings; each binding can either reference an existing TriggerBinding or embedded a TriggerBinding definition using a name/value pair.
    • [template] - Specifies the corresponding TriggerTemplate either as a reference as an embedded TriggerTemplate definition.
    • [interceptors] - (Optional) specifies one or more Interceptors that will process the payload data before passing it to the TriggerTemplate.
    • ref - a reference to a ClusterInterceptor or Interceptor object with the following fields:
      • name - the name of the referenced ClusterInterceptor
      • kind - (Optional) specifies that whether the referenced Kubernetes object is a ClusterInterceptor object or NamespacedInterceptor. Default value is ClusterInterceptor
    • [serviceAccountName] - (Optional) Specifies the ServiceAccount to supply to the EventListener to instantiate/execute the target resources.

Below is an example Trigger definition:

apiVersion: triggers.tekton.dev/v1beta1
kind: Trigger
metadata:
  name: trigger
spec:
  interceptors:
    - ref:
        name: "cel"
      params:
        - name: "filter"
          value: "header.match('X-GitHub-Event', 'pull_request')"
        - name: "overlays"
          value:
            - key: extensions.truncated_sha
              expression: "body.pull_request.head.sha.truncate(7)"
  bindings:
  - ref: pipeline-binding
  template:
    ref: pipeline-template

Specifying the corresponding TriggerTemplate

In the template field, you can do one of the following:

• Use the name parameter to reference an external TriggerTemplate object, or

• Use the spec parameter to directly embed a TriggerTemplate definition.

For example:

# Example: embedded TriggerTemplate definition
triggers:
  - name: "my-trigger"
    template:
      spec: 
        params:
          - name: "my-param-name"
        resourcetemplates:
        - apiVersion: "tekton.dev/v1beta1"
          kind: TaskRun
          metadata:
            generateName: "pr-run-"
          spec:
            taskSpec:
              steps:
              - image: ubuntu
                script: echo "hello there"