本文使用github webhook来触发tekton

准备工作

• 环境配置请参考前文Tekton笔记(一)
• 需要安装tkn命令行工具看这里https://github.com/tektoncd/cli
• 本文所用代码参考https://github.com/tektoncd/triggers/tree/v0.20.0/examples/v1beta1/github

配置EventListener使用LoadBalancer

apiVersion: triggers.tekton.dev/v1beta1
kind: EventListener
metadata:
  name: github-listener
spec:
  serviceAccountName: tekton-triggers-example-sa
  triggers:
    - name: github-listener
      bindings:
        - ref: github-pr-binding
      template:
        ref: github-template
  resources:
    kubernetesResource:
      serviceType: LoadBalancer
      servicePort: 8128

确认LoadBalancer IP

# kubectl get svc
NAME                 TYPE           CLUSTER-IP       EXTERNAL-IP     PORT(S)                         AGE
el-github-listener   LoadBalancer   172.16.255.204   43.135.66.251   8128:30513/TCP,9000:30569/TCP   63m
kubernetes           ClusterIP      172.16.252.1     <none>          443/TCP                         109m

无验证的简单webhook

添加TriggerBinding，TriggerTemplate

apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerBinding
metadata:
  name: github-pr-binding
spec:
  params:
    - name: gitrevision
      value: $(body.pull_request.head.sha)
    - name: gitrepositoryurl
      value: $(body.repository.clone_url)
---
apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerTemplate
metadata:
  name: github-template
spec:
  params:
    - name: gitrevision
    - name: gitrepositoryurl
  resourcetemplates:
    - apiVersion: tekton.dev/v1beta1
      kind: TaskRun
      metadata:
        generateName: github-run-
      spec:
        serviceAccountName: tekton-triggers-example-sa
        taskSpec:
          steps:
            - image: ubuntu
              script: |
                #! /bin/bash
                echo "Revision is : $(tt.params.gitrevision). RepoURL is $(tt.params.gitrepositoryurl)"

其中TriggerBinding只是从webhook的json请求中提取$(body.pull_request.head.sha)， $(body.repository.clone_url)

TriggerTemplate最终在log里打印这两个参数

这里接受的必须是pull_request请求。如果是push的请求则没有pull_request字段，不会触发tekton。

手动测试

curl -v \
-H 'X-GitHub-Event: pull_request' \
-H 'X-Hub-Signature: sha1=ba0cdc263b3492a74b601d240c27efe81c4720cb' \
-H 'Content-Type: application/json' \
-d '{"action": "opened", "pull_request":{"head":{"sha": "28911bbb5a3e2ea034daf1f6be0a822d50e31e73"}},"repository":{"clone_url": "https://github.com/tektoncd/triggers.git"}}' \
http://43.135.66.251:8128

在dashboard上可以看到已经触发taskRun

有token验证的webhook

先配置github webhook

进一步配置EventListener

在EventListener里增加两个interceptors

apiVersion: v1
kind: Secret
metadata:
  name: github-secret
type: Opaque
stringData:
  secretToken: "1234567"

---
apiVersion: triggers.tekton.dev/v1beta1
kind: EventListener
metadata:
  name: github-listener
spec:
  serviceAccountName: tekton-triggers-example-sa
  triggers:
    - name: github-listener
      interceptors:
        - ref:
            name: "github"
          params:
            - name: "secretRef"
              value:
                secretName: github-secret
                secretKey: secretToken
            - name: "eventTypes"
              value: ["pull_request"]
        - name: "only when PRs are opened"
          ref:
            name: "cel"
          params:
            - name: "filter"
              value: "body.action in ['opened', 'synchronize', 'reopened']"
      bindings:
        - ref: github-pr-binding
      template:
        ref: github-template
  resources:
    kubernetesResource:
      serviceType: LoadBalancer
      servicePort: 8128

这里的interceptors里使用了两个ClusterInterceptors

Interceptors github用来验证github的请求。secretRef对应最上面的kind: Secret。

用来验证github在x-hub-signature-256 header里的token

详细可以参考：https://docs.github.com/en/developers/webhooks-and-events/webhooks/securing-your-webhooks

Interceptors cel 则是限制请求类型

关于其他几个Interceptors的具体文档请看这里https://tekton.dev/docs/triggers/interceptors/

创建PR测试webhook

github上查看webhook

tekton dashboard上验证正常触发

从最后一张图可以看到打印出来的Revision和 RepoURL

Troubleshooting

用tkn cli查看触发记录，如果因为配置错误无法解析json的话，这里会有报错。

# tkn eventlistener list
NAME              AGE          URL                                                        AVAILABLE
github-listener   1 hour ago   http://el-github-listener.default.svc.cluster.local:8080   True

# tkn eventlistener logs github-listener -t 3
[github-listener-el-github-listener-67b6d4f458-l5nrz]: {"severity":"info","timestamp":"2022-09-13T02:29:36.195Z","logger":"eventlistener","caller":"sink/sink.go:409","message":"ResolvedParams : [{Name:gitrevision Value:5bbd66a94e90ef3e2476795f30dc7830fc8c76a8} {Name:gitrepositoryurl Value:https://github.com/massivezh/xxx.git}]","eventlistener":"github-listener","namespace":"default","/triggers-eventid":"6d7a5bc8-4ccd-496f-9ac8-d56e3a8f2c08","eventlistenerUID":"614731e5-fae4-41ee-8762-ec9bfb21f8c8","/triggers-eventid":"6d7a5bc8-4ccd-496f-9ac8-d56e3a8f2c08","/trigger":"github-listener"}
[github-listener-el-github-listener-67b6d4f458-l5nrz]: {"severity":"info","timestamp":"2022-09-13T02:29:36.196Z","logger":"eventlistener","caller":"resources/create.go:98","message":"Generating resource: kind: &APIResource{Name:taskruns,Namespaced:true,Kind:TaskRun,Verbs:[delete deletecollection get list patch create update watch],ShortNames:[tr trs],SingularName:taskrun,Categories:[tekton tekton-pipelines],Group:tekton.dev,Version:v1beta1,StorageVersionHash:Z11in7AH8TA=,}, name: github-run-"}
[github-listener-el-github-listener-67b6d4f458-l5nrz]: {"severity":"info","timestamp":"2022-09-13T02:29:36.196Z","logger":"eventlistener","caller":"resources/create.go:106","message":"For event ID \"6d7a5bc8-4ccd-496f-9ac8-d56e3a8f2c08\" creating resource tekton.dev/v1beta1, Resource=taskruns"}

参考文档：https://tekton.dev/docs/triggers/troubleshooting/