TriggerBindings 概述

TriggerBinding的功能主要用于将Event中特定属性的值传递给TriggerTemplate上的参数从而完成其resourcetemplates中模板资源的实例化。

注意：Trigger使用参数名称将 TriggerBinding 参数与 TriggerTemplate 参数匹配。为了传递信息，绑定中使用的参数名称必须与模板中使用的参数名称匹配。

TriggerBindings 资源规范

spec字段中，主要定义params，每个Parameters主要是name和value两个字段组成

apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerBinding
metadata:
  name: pipeline-binding
spec:
  params:
  - name: gitrevision                     # 为同一Trigger当中引用的TriggerTemplate上声明的某个参数的名称
    value: $(body.head_commit.id)         # 通常要引用Event中的特定属性，例如$(body.head_commit.id)

TriggerBindings 声明方式

内联绑定

声明绑定的最简单方法是在Trigger本身内

apiVersion: triggers.tekton.dev/v1beta1
kind: Trigger
metadata:
  name: push-trigger
spec:
  bindings:
  - name: gitrevision
    value: $(body.head_commit.id)
  - name: gitrepositoryurl
    value: $(body.repository.url)
  template:
    ref: git-clone-template

TriggerBindings 

定义 TriggerBindings

apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerBinding
metadata:
  name: pipeline-binding
spec:
  params:
  - name: gitrevision
    value: $(body.head_commit.id)
  - name: gitrepositoryurl
    value: $(body.repository.url)
  - name: contenttype
    value: $(header.Content-Type)

引用 TriggerBindings

apiVersion: triggers.tekton.dev/v1beta1
kind: Trigger
metadata:
  name: push-trigger
spec:
  bindings:
  - ref: pipeline-binding
  template:
    ref: git-clone-template

ClusterTriggerBindings 

ClusterTriggerBinding 是集群范围内的 TriggerBinding，您可以在整个集群中重复使用它。可以在任何命名空间的任何Trigger中引用 ClusterTriggerBinding。可以在Trigger中指定多个 ClusterTriggerBinding，也可以在多个Trigger中指定相同的 ClusterTriggerBinding

定义 ClusterTriggerBindings 

apiVersion: triggers.tekton.dev/v1beta1
kind: ClusterTriggerBinding
metadata:
  name: pipeline-clusterbinding
spec:
  params:
    - name: gitrevision
      value: $(body.head_commit.id)
    - name: gitrepositoryurl
      value: $(body.repository.url)
    - name: contenttype
      value: $(header.Content-Type)

引用 ClusterTriggerBindings

引用 ClusterTriggerBinding 时，必须在绑定字段中指定种类值。默认值是 TriggerBinding，它表示命名空间的 TriggerBinding。

---
apiVersion: triggers.tekton.dev/v1beta1
kind: EventListener
metadata:
  name: listener-clustertriggerbinding
spec:
  serviceAccountName: tekton-triggers-example-sa
  triggers:
    - name: foo-trig
      bindings:
        - ref: pipeline-clusterbinding
          kind: ClusterTriggerBinding
        - ref: message-clusterbinding
          kind: ClusterTriggerBinding
      template:
        ref: pipeline-template

访问 HTTP JSON 格式数据

方法一

$(body.key1)
$(.body.key)

方法二

如果 $() 包装器嵌入到另一个 $() 包装器中，Tekton 会将最内层包装器的内容解析为 JSONPath 表达式

$($(body.b)) # Parsed as $(body.b)
$($($(body.b))) # Parsed as $(body.b)

Interceptors 访问overlays数据

interceptor可以添加可供 TriggerBinding 使用的其他有用数据。interceptor添加的数据可以在顶级extensions字段下访问，例如$(extensions.field-name).在以下示例中，CEL 拦截器添加一个字段，然后由trigger binding访问该字段

apiVersion: triggers.tekton.dev/v1beta1
kind: Trigger
metadata:
  name: push-trigger
spec:
  interceptors:
    - name: add-truncated-sha
      ref:
        name: "cel"
      params:
        - name: "overlays"
          value:
          - key: truncated_sha
            expression: "body.pull_request.head.sha.truncate(7)"
  bindings:
    - name: truncated_sha
      value: $(extensions.truncated_sha)
  template:
    ref: git-clone-template

访问 EventListener Event Context

EventListener 有一组内部数据点，这些数据点是为单个事件的完整处理而维护的。这些值可用于TriggerBinding对象。可以通过context参数访问此数据。

$(context.eventID) # access the internal eventID of the request

访问带有特殊字符的 json

要访问包含句点 (.) 的 JSON 键，必须使用反斜杠 (\.) 转义句点。

# Body contains a `tekton.dev` field: {"body": {"dev.tekton.dev/foo": "triggers"}}
$(body.dev\.tekton\.dev\/foo) -> "triggers"

TriggerBindings 示例

apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: event-binding
spec:
  params:
    - name: gitrevision
      value: $(body.head_commit.id)
    - name: gitrepositoryurl
      value: $(body.repository.url)
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: prod-env
spec:
  params:
    - name: environment
      value: prod
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: staging-env
spec:
  params:
    - name: environment
      value: staging
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: EventListener
metadata:
  name: listener
spec:
  triggers:
    - name: prod-trigger
      bindings:
        - ref: event-binding
        - ref: prod-env
      template:
        ref: pipeline-template
    - name: staging-trigger
      bindings:
        - ref: event-binding
        - ref: staging-env
      template:
        ref: pipeline-template

参考文档

https://tekton.dev/docs/triggers/triggerbindings/