如何将GitHub Webhook参数、Helm镜像信息传入Tekton Pipeline？

一、GitHub Webhook 参数传入 Tekton Pipeline #

需要通过Tekton Triggers组件完成Webhook参数的接收和映射，操作步骤如下：

1. 在TriggerTemplate中定义与GitHub Webhook payload字段对应的Pipeline参数，映射后传递给PipelineRun

# trigger-template.yaml 示例
apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerTemplate
spec:
  params:
    - name: git-repo-url
      description: GitHub 仓库地址，来自Webhook payload的repository.url字段
    - name: git-revision
      description: 提交哈希，来自Webhook payload的after字段
  resourcetemplates:
  - apiVersion: tekton.dev/v1beta1
    kind: PipelineRun
    spec:
      pipelineRef:
        name: your-pipeline
      params:
        - name: REPO_URL
          value: $(tt.params.git-repo-url)
        - name: REVISION
          value: $(tt.params.git-revision)

2. 在TriggerBinding中完成Webhook payload字段到TriggerTemplate参数的映射

# trigger-binding.yaml 示例
apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerBinding
spec:
  params:
    - name: git-repo-url
      value: $(body.repository.url)
    - name: git-revision
      value: $(body.after)

EventListener收到GitHub Webhook请求后，会自动提取payload对应字段，通过TriggerTemplate传递给PipelineRun，在Pipeline中定义同名接收参数即可拿到对应值。 #

二、从Helm清单提取字段传递给Tekton Task #

需要先将代码拉取到Pipeline共享工作区，再通过yq工具读取Helm配置字段，推荐两种实现方案可按需选择：

方案1：新增前置Task提取参数（推荐，参数可跨Task复用） #

新增专门的Helm字段提取Task，将读取结果输出为Task结果，再传递给已有Task

• 第一步：定义提取字段的Task

# helm-extract-task.yaml
apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: extract-helm-params
spec:
  workspaces:
    - name: source
      description: 存放拉取后源码的工作区
  results:
    - name: image-repo
      description: 从values.yaml读取的镜像仓库地址
    - name: image-tag
      description: 从Chart.yaml读取的镜像标签
  steps:
    - name: extract-fields
      image: mikefarah/yq:4
      script: |
        # 读取values.yaml的image字段写入结果
        yq eval '.image' $(workspaces.source.path)/values.yaml | tr -d '\n' > $(results.image-repo.path)
        # 读取Chart.yaml的appVersion字段写入结果
        yq eval '.appVersion' $(workspaces.source.path)/Chart.yaml | tr -d '\n' > $(results.image-tag.path)

• 第二步：在Pipeline中编排执行顺序，传递提取结果给已有Task

注：你原有Task的IMAGE_TAG参数描述写错了，建议修正为The image tag

# pipeline.yaml 示例
apiVersion: tekton.dev/v1beta1
kind: Pipeline
spec:
  workspaces:
    - name: shared-workspace
  tasks:
    - name: fetch-source
      taskRef:
        name: git-clone
      workspaces:
        - name: output
          workspace: shared-workspace
      params:
        - name: url
          value: $(params.REPO_URL)
        - name: revision
          value: $(params.REVISION)
    - name: extract-helm
      taskRef:
        name: extract-helm-params
      runAfter: ["fetch-source"]
      workspaces:
        - name: source
          workspace: shared-workspace
    - name: your-existing-task
      taskRef:
        name: your-task-name # 替换为你已定义的Task名称
      runAfter: ["extract-helm"]
      params:
        - name: IMAGE_REPO
          value: $(tasks.extract-helm.results.image-repo)
        - name: IMAGE_TAG
          value: $(tasks.extract-helm.results.image-tag)

方案2：直接在现有Task内部提取参数 #

如果参数仅在单个Task内部使用，无需跨Task传递，可以直接在现有Task的steps最前面增加提取步骤，读取值作为环境变量供后续步骤使用：

# 改造后的tekton-task.yaml示例
apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: your-task-name
spec:
  workspaces:
    - name: source
      description: 存放源码的工作区
  params:
    - name: IMAGE_REPO
      description: The image registry
    - name: IMAGE_TAG
      description: The image tag
  steps:
    - name: extract-helm-fields
      image: mikefarah/yq:4
      script: |
        export IMAGE_REPO=$(yq eval '.image' $(workspaces.source.path)/values.yaml)
        export IMAGE_TAG=$(yq eval '.appVersion' $(workspaces.source.path)/Chart.yaml)
        # 后续步骤直接调用上述两个环境变量即可
    # 原有后续步骤不变

内容的提问来源于stack exchange，提问作者Ash Poblete