云原生的 CI/CD 框架tekton – Trigger（二）

本文介绍: 上一篇为大家详细介绍了，由于里面涉及到的概念比较多，因此需要好好消化下。同样，今天在特别为大家分享下tekton – Trigger以及案例演示，希望可以给大家提供一种思路哈。

上一篇为大家详细介绍了tekton – pipeline，由于里面涉及到的概念比较多，因此需要好好消化下。同样，今天在特别为大家分享下tekton – Trigger以及案例演示，希望可以给大家提供一种思路哈。

文章目录

1. Tekton Trigger

Trigger 组件就是用来解决这个触发问题的，它可以从各种来源的事件中检测并提取需要信息，然后根据这些信息来创建 TaskRun 和 PipelineRun，还可以将提取出来的信息传递给它们以满足不同的运行要求。

Tekton Trigger中有6类对象，分别是：

EventListener：事件监听器，是外部事件的入口，通常需要通过HTTP方式暴露，以便于外部事件推送，比如配置Gitlab的Webhook。
Trigger：指定当 EventListener 检测到事件发生时会发生什么，它会定义 TriggerBinding、TriggerTemplate 以及可选的 Interceptor。
TriggerTemplate：用于模板化资源，根据传入的参数实例化 Tekton 对象资源，比如 TaskRun、PipelineRun等。
TriggerBinding：用于捕获事件中的字段并将其存储为参数，然后会将参数传递给 TriggerTemplate。
ClusterTriggerBinding：和 TriggerBinding 相似，用于提取事件字段，不过它是集群级别的对象。
Interceptors：拦截器，在 TriggerBinding 之前运行，用于负载过滤、验证、转换等处理，只有通过拦截器的数据才会传递给TriggerBinding。

2. 工作流程

在这里插入图片描述

step1：EventListener 用于监听外部事件（具体触发方式为 http），外部事件产生后被 EventListener 捕获，然后进入处理过程。
step2：首先会由 Interceptors 来进行处理（如果有配置 interceptor 的话），对负载过滤、验证、转换等处理，类似与 http 中的 middleware。
step3：Interceptors 处理完成后无效的事件就会被直接丢弃，剩下的有效事件则交给 TriggerBinding 处理，
step4：TriggerBinding 实际上就是从事件内容中提取对应参数，然后将参数传递给 TriggerTemplate。
step5：TriggerTemplate 则根据预先定义的模版以及收到的参数创建 TaskRun 或者 PipelineRun 对象。
step6：TaskRun 或者 PipelineRun 对象创建之后就会触发对应 task 或者 pipeline 运行，整个流程就全自动了。

3. 安装trigger和interceptors

# install reigger
kubectl apply --filename https://storage.googleapis.com/tekton-releases/triggers/latest/release.yaml
# install interceptors
kubectl apply --filename https://storage.googleapis.com/tekton-releases/triggers/latest/interceptors.yaml

# monitor
kubectl get pods --namespace tekton-pipelines --watch

4. 案例

案例: gitlab跳代码触发tekton

step1: 创建task – 拉取代码

同pipeline案例2

step2: 创建task – 构建代码

同pipeline案例2

step3: 创建task – 打包镜像

task-package.yaml

apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: package-2
spec:
  workspaces:
    - name: source # 名称
  params:
   - name: image_dest
     type: string
     default: "registry.ap-southeast-1.aliyuncs.com/my_image_repo"
   - name: sha
     type: string
     default: "latest"
   - name: DockerfilePath
     type: string
     default: Dockerfile
   - name: Context
     type: string
     default: .
   - name: project_name
     type: string
     default: "test"
  steps:
  - name: package
    image: docker:stable
    workingDir: $(workspaces.source.path)
    script: |
      #/usr/bin/env sh
      Tag=$(params.sha)
      tag=${Tag:0:6}
      docker login registry.ap-southeast-1.aliyuncs.com
      docker build -t $(params.image_dest)/$(params.project_name):${tag} -f $(params.DockerfilePath) $(params.Context)
      docker push $(params.image_dest)/$(params.project_name):${tag}
    volumeMounts:
      - name: dockersorck
        mountPath: /var/run/docker.sock
  volumes:
    - name: dockersorck
      hostPath:
        path: /var/run/docker.sock

step4: 创建pipeline

pipeline.yaml

apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: clone-build-push-2
spec:
  description: |
    This pipeline clones a git repo, builds a Docker image with Kaniko and
    pushes it to a registry
  params:
  - name: repo-url
    type: string
  - name: sha
    type: string
  - name: project_name
    type: string
  - name: version
    type: string
  workspaces:
  - name: shared-data
  tasks:
  # 拉取代码
  - name: fetch-source
    taskRef:
      name: git-clone
    workspaces:
    - name: output
      workspace: shared-data
    params:
    - name: url
      value: $(params.repo-url)
    - name: revision
      value: $(params.version)
  # 打包
  - name: build-code
    taskRef:
      name: build-2
    workspaces:
    - name: source
      workspace: shared-data
    runAfter:
      - fetch-source
  # 构建并推送镜像
  - name: package-image
    runAfter: ["build-code"]
    taskRef:
      name: package-2
    workspaces:
    - name: source
      workspace: shared-data
    params:
    - name: sha
      value: $(params.sha)
    - name: project_name
      value: $(params.project_name)

step5: 创建pipelinerun

pipelinerun.yaml

apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  generateName: clone-build-push-run-
  #name: clone-build-push-run
spec:
  serviceAccountName: gitlab-sa
  pipelineRef:
    name: clone-build-push-2
  podTemplate:
    securityContext:
      fsGroup: 65532
  workspaces:
  - name: shared-data
    volumeClaimTemplate:
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 128Mi
  params:
  - name: repo-url
    value: git@jihulab.com:cs-test-group1/kxwang/test.git #https://jihulab.com/cs-test-group1/kxwang/test.git
  - name: sha
    value: bchdsvhj12312312312241421
#  - name: image_tag
#    value: v2
  - name: version
    value: refs/heads/master
  - name: project_name
    value: wkx

step6: 创建事件监听器

EventListener.yaml

apiVersion: triggers.tekton.dev/v1alpha1
kind: EventListener
metadata:
  name: gitlab-listener  # 该事件监听器会创建一个名为el-gitlab-listener的Service对象
  namespace: default
spec:
  resources:
    kubernetesResource:
      serviceType: NodePort
  serviceAccountName: gitlab-sa
  triggers:
  - name: gitlab-push-events-trigger
    interceptors:
    - ref:
        name: gitlab
      params:
      - name: secretRef  # 引用 gitlab-secret 的 Secret 对象中的 secretToken 的值
        value:
          secretName: gitlab-webhook
          secretKey: secretToken
      - name: eventTypes
        value:
          - Push Hook # 只接收 GitLab Push 事件
    bindings:
    - ref: pipeline-binding
    template:
      ref: pipeline-template

step7: 创建TriggerBinding文件

TriggerBinding.yaml

apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerBinding
metadata:
  name: pipeline-binding
spec:
  params:
  - name: repo-url
    value: $(body.repository.git_ssh_url)
  - name: version
    value: $(body.ref)
  - name: sha
    value: $(body.checkout_sha)
  - name: project_name
    value: $(body.project.name)

step8: 创建TriggerTemplate模版文件

TriggerTemplate.yaml

apiVersion: v1
kind: Secret
metadata:
  name: gitlab-webhook
type: Opaque
stringData:
  secretToken: '123456789'
[root@VM-0-14-centos class-4]# cat TriggerTemplate.yaml
apiVersion: triggers.tekton.dev/v1beta1
kind: TriggerTemplate
metadata:
  name: pipeline-template
spec:
  params:
  - name: sha
  - name: project_name
  - name: version
  - name: repo-url
  resourcetemplates:
  - apiVersion: tekton.dev/v1beta1
    kind: PipelineRun
    metadata:
      generateName:  clone-build-push-run-
    spec:
      serviceAccountName: gitlab-sa
      pipelineRef:
        name: clone-build-push-2
      params:
      - name: sha
        value: $(tt.params.sha)
      - name: version
        value: $(tt.params.version)
      - name: repo-url
        value: $(tt.params.repo-url)
      - name: project_name
        value: $(tt.params.project_name)
      workspaces:
      - name: shared-data
        volumeClaimTemplate:
          spec:
            accessModes:
            - ReadWriteOnce
            resources:
              requests:
                storage: 128Mi

step9: 创建sa

gitlab-sa.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: gitlab-sa
secrets:
- name: gitlab-auth
- name: gitlab-ssh
- name: docker-credentials
- name: gitlab-webhook

step10: 创建gitlab webhook的信息

secret-gitlab-webhook.yaml

apiVersion: v1
kind: Secret
metadata:
  name: gitlab-webhook
type: Opaque
stringData:
  secretToken: '123456789'

step11: 创建RBAC

rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: gitlab-sa
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: triggers-gitlab-clusterrole
rules:
  # Permissions for every EventListener deployment to function
  - apiGroups: ["triggers.tekton.dev"]
    resources: ["eventlisteners", "triggerbindings", "triggertemplates","clustertriggerbindings", "clusterinterceptors","interceptors","triggers"]
    verbs: ["get","list","watch"]
  - apiGroups: [""]
    # secrets are only needed for Github/Gitlab interceptors, serviceaccounts only for per trigger authorization
    resources: ["configmaps", "secrets", "serviceaccounts"]
    verbs: ["get", "list", "watch"]
  # Permissions to create resources in associated TriggerTemplates
  - apiGroups: ["tekton.dev"]
    resources: ["pipelineruns", "pipelineresources", "taskruns"]
    verbs: ["create"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: triggers-gitlab-clusterrolebinding
subjects:
  - kind: ServiceAccount
    name: gitlab-sa
    namespace: default
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: triggers-gitlab-clusterrolegitlab-sa.yaml