2022 第43週 學習筆記：.gitlab-ci.yml

總結

關於 .gitlab-ci.yml 基本語法與規則的自用筆記，以目前工作上有用到的內容為主。

筆記

大前提：檔案必定命名為 .gitlab-ci.yml 且放置在 repo 根目錄中

關鍵字

• GitLab Runner: is an application that works with GitLab CI/CD to run jobs in a pipeline.
• CI/CD Pipelines: are the top-level component of continuous integration, delivery, and deployment. Pipelines comprise:
  • Jobs, which define what to do. For example, jobs that compile or test code.
  • Stages, which define when to run the jobs. For example, stages that run tests after stages that compile the code.
• Jobs: Pipeline configuration begins with jobs. Jobs are the most fundamental element of a .gitlab-ci.yml file.

基礎語法

stages:
  - build
  - test

build-code-job:
  stage: build
  script:
    - echo "Check the ruby version, then build some Ruby project files:"
    - ruby -v
    - rake

test-code-job1:
  stage: test
  script:
    - echo "If the files are built successfully, test some files with one command:"
    - rake test1

test-code-job2:
  stage: test
  script:
    - echo "If the files are built successfully, test other files with a different command:"
    - rake test2

• stages: 定義好的 stage 會從上到下依序發生
• jobs: 範例中的 build-code-job、test-code-job1 與 test-code-job2
  • 會先執行設定在 stage: build 的 build-code-job，如果此 job 順利結束，則 stage test 中的 test-code-job1 與 test-code-job2 會同時開始執行（沒有先後之分）
• script: 在此區塊設定要在 runner 中執行的指令

其他常見關鍵字

artifacts: Jobs can output an archive of files and directories. This output is known as a job artifact. They are available for download in the GitLab UI if the size is smaller than the the maximum artifact size. By default, jobs in later stages automatically download all the artifacts created by jobs in earlier stages.

簡單來說就是 gitlab-ci 的檔案機制，且後發的 jobs 預設會下載先行 jobs 產生的 artifacts 下方範例翻成白話文即是：在 job pdf 中，透過指令 xelatex mycv.tex 產生 pdf 檔案，並產生出來的檔案 mycv.pdf 一週後過期

pdf:
  script: xelatex mycv.tex
  artifacts:
    paths:
      - mycv.pdf
    expire_in: 1 week

dependencies: 指定 artifacts 來源

build osx:
  stage: build
  script: make build:osx
  artifacts:
    paths:
      - binaries/

build linux:
  stage: build
  script: make build:linux
  artifacts:
    paths:
      - binaries/

test osx:
  stage: test
  script: make test:osx
  dependencies:
    - build osx # 在這個 job 取用 build osx 產生的檔案

test linux:
  stage: test
  script: make test:linux
  dependencies:
    - build linux # 在這個 job 取用 build linux 產生的檔案

deploy:
  stage: deploy
  script: make deploy
  environment: production

extends: 功能如關鍵字本身的描述，可在此定義可複用的內容，並讓其他 jobs 引用

# 以下這個組合
.tests:
  script: rake test
  stage: test
  only:
    refs:
      - branches

rspec:
  extends: .tests
  script: rake rspec
  only:
    variables:
      - $RSPEC

# 最終的結果等同於
rspec:
  script: rake rspec
  stage: test
  only:
    refs:
      - branches
    variables:
      - $RSPEC

image: 指定 jobs 的執行環境，注意僅能在 default 或 job 中指名要使用的 Docker image

default:
  image: ruby:3.0

rspec:
  script: bundle exec rspec

rspec 2.7:
  image: registry.example.com/my-group/my-project/ruby:2.7
  script: bundle exec rspec

variables: 定義在 .gitlab-ci.yml 最上方為全域變數，定義在 jobs 中則只有該 job 可以使用

variables:
  TEST_VAR: "All jobs can use this variable's value"

job1:
  variables:
    TEST_VAR_JOB: "Only job1 can use this variable's value"
  script:
    - echo "$TEST_VAR" and "$TEST_VAR_JOB"

參考文件

• GitLab Docs: The .gitlab-ci.yml file
• GitLab Docs: .gitlab-ci.yml keyword reference
• YouTube: GitLab CI CD Tutorial for Beginners [Crash Course]