前言
前面講了一些需要注意的東西，這篇就把所有的設定都實例化來好好的講清楚。
EventListener
前面提到過這邊主要是負責事件的監聽，所有的監聽入口皆在這邊做設定。
apiVersion: triggers.tekton.dev/v1alpha1
kind: EventListener
metadata:
name: webhook
spec:
serviceAccountName: pipeline
triggers:
- name: git-webhook-PR
bindings:
- ref: git-webhook-triggerbinding
template:
ref: git-api-trigger-template
interceptors:
- github:
eventTypes:
- pull_request
- cel:
filter: "body.pull_request.merged in [true]"
overlays:
- key: "truncated_sha"
expression: "truncate(body.pull_request.merge_commit_sha, 8)"
以上範例的相關設定在官方的catalog github裡挖的到，也有gitlab和bitbucket的範例。
這邊主要是建立webhook後的接收分析，經由interceptors去做parse接收response的格式化，主要先使用google cel-spec(全名Common Expression Language)做後續設定key以及正規化我要擷取的部份(這邊是把merge commit的sha擷取後只取前8位並指給truncated_sha這個key)。
接下來是把解析後的資料塞到git-webhook-triggerbinding設定的參數以及呼叫git-api-trigger-template執行接下來的動作
TriggerBinding
先講這塊是因為這邊比較單純，可以結合上面的接收解析資料來代入範例
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
name: git-webhook-triggerbinding
spec:
params:
- name: gitrevision
value: $(body.after)
- name: gitrepositoryurl
value: $(body.repository.clone_url)
- name: revision
value: $(body.pull_request.head.sha)
- name: repo_owner
value: $(body.pull_request.base.repo.owner.username)
- name: repo_name
value: $(body.pull_request.base.repo.name)
- name: commit_sha
value: $(body.pull_request.merge_commit_sha)
- name: commit_short_sha
value: $(expression.truncated_sha)
- name: commit_branch
value: $(body.pull_request.base.repo.default_branch)
- name: commit_author
value: $(body.pull_request.user.username)
- name: commit_msg
value: $(body.pull_request.body)
- name: commit_author_email
value: $(body.pull_request.user.email)
- name: build_number
value: $(body.number)
以上範例相關的格式也可以在官網裡翻到，這邊稍微講一下就好，主要解析的格式是上面提過的response內容，基本上git回的應該都是json格式，所以範例裡body指的就是整個json的本身，而這邊因為是擷取pull request為主，所以$(body.pull_request.head.sha)指的就是response裡的值(如下所示)
{
"pull_request": {
"head": {
"sha": ""
}
}
}
這邊只要搞懂怎麼看就容易理解了，至於$(expression.truncated_sha)怎麼來的呢？就是上面EventListener裡額外擷取出merge_commit_sha前8碼給truncated_sha的部份。所以這一整個TriggerBinding就是解析整個response回來的json裡的值且依照你的設定指給你想要的參數。
TriggerTemplate
接下來這邊就是整個Trigger裡最後的部份，也是牽扯最多設定的地方。
apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerTemplate
metadata:
name: git-api-trigger-template
spec:
params:
- name: gitrevision
description: The git revision
# default: staging
default: master
- name: gitrepositoryurl
description: The git repository url
- name: repo_owner
description: the repository owner
- name: repo_name
description: the repository owner name
- name: commit_sha
description: git push commit sha tag
- name: commit_short_sha
description: git push commit sha short tag
- name: commit_branch
description: git push commit branch
- name: commit_author
description: git push commit author
- name: commit_author_email
description: git push commit author email
- name: commit_msg
description: git push commit message
- name: build_number
description: build number
resourcetemplates:
- apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
generateName: api-golang-stack-
labels:
tekton.dev/pipeline: golang-stack-pipeline
spec:
serviceAccountName: pipeline
pipelineRef:
name: golang-stack-pipeline-uat
params:
- name: git-repo-url
value: '$(tt.params.gitrepositoryurl)'
- name: git-repo-revision
value: '$(tt.params.gitrevision)'
- name: image-name
# For OpenShift builds, this should be patched to point to a suitable image stream for the project
value: your.url.path/your-project-$(tt.params.commit_branch)
- name: secret
value: ses-secret
- name: mail_from
value: 'user@mail'
- name: mail_recipients
value: "user@mail"
- name: mail_repo_owner
value: '$(tt.params.repo_owner)'
- name: mail_repo_name
value: '$(tt.params.repo_name)'
- name: mail_commit_sha
value: '$(tt.params.commit_short_sha)'
- name: mail_commit_branch
value: '$(tt.params.commit_branch)'
- name: mail_commit_author
value: '$(tt.params.commit_author)'
- name: mail_commit_author_email
value: '$(tt.params.commit_author_email)'
- name: mail_commit_msg
value: '$(tt.params.commit_msg)'
- name: mail_build_number
value: '$(tt.params.build_number)'
- name: mail_build_link
value: '$(tt.params.build_link)'
- name: buildImageUrl
value: your.url.path/your-project-$(tt.params.commit_branch):$(tt.params.commit_short_sha)'
workspaces:
- name: source
persistentVolumeClaim:
claimName: tekton-api-sources
這邊說穿了其實就只是個把pipeline運行之前需要的資料一一的寫入後並把需要被執行的pipeline指定好就可以了。
看起來好像很簡單，我自己寫起來有點像是C++的感覺，要先在上面的spec.params裡宣告好需要的參數，接著在spec.resourcetemplates.spec.params裡傳入對應的值，而這些值會經由TriggerTemplate傳入spec.resourcetemplates.spec.pipelineRef.name指定的pipeline
總結
這篇就到這邊，之後再找時間來講講比較細節的東西，希望以上的講解可以讓一些剛接觸的人比較好理解裡面的運作情形，如果有什麼錯誤歡迎討論。