# GitLab Runner
###### tags: `gitlab`

GitLab Runner 即是為你代勞執行 CI Job 的 Worker，如果有架設多個 CI Runner 那麼在同一時間即可處理多項 CI Job，反之如果有大量的 CI Job 需要執行，但 Runner 數量有限，那麼 CI Job 就會出現 Pending 的狀態，必須等待 Runner 完成其他工作之後，才會輪到該 CI Job 被執行。


## Register a Runner

Gitlab Runner 可透過兩種方式向Gitlab註冊，互動式與非互動式，選擇互動式時，系統會向您詢問多個問題，例如Gitlab位置、Runner名稱、Token等等，非互動式會需要您直接從命令中指定參數的方式。

### Runner configuration

concurrent = 4
check_interval = 0

[[runners]]
  name = "dind"
  output_limit = 41943040
  url = "https://gitlab.com.tw"
  token = "yourtoken"
  executor = "docker"
  environment = ["GIT_SSL_NO_VERIFY=true", "DOCKER_TLS_CERTDIR=/certs"]
  [runners.docker]
    tls_verify = false
    image = "docker:18"
    privileged = true
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = false
    volumes = ["/certs/client", "/cache"]
    extra_hosts = ["example.com.tw:10.1.0.4", "reg-example.com.tw:10.1.0.4"]
    shm_size = 0

- concurrent : 限制同時運行的作業數
- check_interval: 定義新作業檢查之間的間隔長度（以秒為單位）
- output_limit: 設定build log大小,會影響在Gitlab job log的最大範圍
- token: 從Gitlab產出的token，會有全域與專案之分，如果是專案token，只有此專案才看的到透過專案token註冊的Runner(Config中的Token是runner的名稱)
- executor: Runner: 會透過哪種方式執行Job,有shell、docker、kubernetes等等
- environment: Runner在執行Job時，如git clone會使用到的環境變數
- image: Job預設執行的image
- volumes:
["/path/to/volume/in/container"] : 避免container stop 後資料遺失
["/path/to/bind/from/host:/path/to/bind/in/container:rw"] : 共享host與container內的目錄
- extra_hosts: 指定容器中的/etc/hosts

## GitLab CI/CD Pipeline Configuration
GitLab CI 會檢查專案內否含有<abbr title="Hyper Text Markup Language">.gitlab-ci.yml</abbr>，並根據該檔案所定義的內容自動建立 CI/CD Pipeline

### stages & jobs
定義一個作業階段，同一階段可以有多個Job

stages:
  - build
  - test
  - deploy

build-job:
  stage: build
  script:
    - echo "build"

test-job:
  stage: test
  script:
    - echo "testing"

deploy-job:
  stage: deploy
  script:
    - echo "deploy"


### 全域設定值

可以在<abbr title="Hyper Text Markup Language">default:</abbr>內定義以下作業參數：

- image
- services
- before_script
- after_script
- tags
- cache
- artifacts
- retry
- timeout
- interruptible

default:
  image: alpine  #1
  before_script:  #2
    - echo "I am before_script"
    - cat "/etc/*-release"

  after_script:  #3
    - echo "I am after_script:"
  tags:  #4
    - dind

stages:
  - build

build-job:
  stage: build
  script:
    - echo "build"


### variables

stages:
  - build

variables:
  VAR: iamvariables

build-job:
  stage: build
  script:
    - echo ${VAR}


###

### service
用來指定服務Docker image，此服務會與build container一起啟動，並鏈接在一起

stages:
  - build

services:
  - name: docker:dind
    command: ["--insecure-registry=registry-fortress.fareastone.com.tw"]

build-job:
  stage: build
  script:
    - cat /etc/hosts
    - echo ${DOCKER_HOST}
    - docker info

Container 狀態


Build container輸出內容

Dind的作法


https://docs.docker.com/engine/reference/commandline/cli/

https://github.com/docker-library/docker/blob/a73d96e731e2dd5d6822c99a9af4dcbfbbedb2be/19.03/dind/Dockerfile

### only/ except

定義Job會在哪個分支上運行

- only
- except

stages:
  - build
  - test
  - deploy

build-job:
  stage: build
  script:
    - echo "build"

test-job:
  stage: test
  script:
    - echo "testing"
  except:
    - branches

deploy-job:
  stage: deploy
  script:
    - echo "deploy"
  only:
    - master

On branch


### allow_failure
允許作業失敗而不會影響CI的其餘部分

啟用後，如果作業失敗，該作業將在UI中顯示橙色驚嘆號。Pipeline的邏輯流程將認為作業成功

stages:
  - build
  - test
  - deploy

build-job:
  stage: build
  script:
    - cat nonexistent_file
  allow_failure: true
  
test-job:
  stage: test
  script:
    - echo "testing"

deploy-job:
  stage: deploy
  script:
    - echo "deploy"


### when
用於上一階段發生故障或發生故障時運行的作業，可以設置為以下值之一：
- on_success
- on_failure
- always
- manual
- delayed

stages:
  - build
  - test
  - deploy

build-job:
  stage: build
  script:
    - cat nonexistent_file

test-job:
  stage: test
  script:
    - echo "testing"
  when: on_failure 

test-job2:
  stage: test
  script:
    - echo "testing2"
  when: always

deploy-job:
  stage: deploy
  script:
    - echo "deploy"
  when: manual


stages:
  - build
  - test
  - deploy

build-job:
  stage: build
  script:
    - echo "build"

test-job:
  stage: test
  script:
    - echo "testing"
  when: on_failure 

test-job2:
  stage: test
  script:
    - echo "testing2"
  when: always

deploy-job:
  stage: deploy
  script:
    - echo "deploy"
  when: manual


### artifacts
用於儲存pipeline中產生的檔案

- name
- paths
- reports
- when :
- on_failure
- always
- expire_in

stages:
  - build
  - test

build-job:
  stage: build
  script:
    - echo "build"
    - touch build-file
  artifacts:
    name: "build-file"
    paths:
      - build-file
    expire_in: 5  mins

After 5 mins

### dependencies
引用上一階段所儲存的檔案，直接將檔案存在工作目錄

stages:
  - build
  - test

build-job:
  stage: build
  script:
    - echo "build"
    - touch build-file
  artifacts:
    name: "build-file"
    paths:
      - build-file
    expire_in: 5  mins

test-job:
  stage: test
  script:
    - echo "testing"
    - ls -al
  dependencies:
    - build-job


### include
將<abbr title="Hyper Text Markup Language">.gitlab-ci.yml</abbr>分成多個文件，可以提高文件可讀性，統一管理一些共用的腳本
- local
- file
- remote
- template

include:
  - project: 'prod-discipline/template-gitlab-ci'
    ref: master
    file: 'container_scanning.yml'


https://gitlab.example.com.tw/group/project/-/blob/master/.gitlab-ci.yml

https://gitlab.example.com.tw/group/template-gitlab-ci/-/blob/master/container_scanning.yml

https://gitlab.com/gitlab-org/gitlab/-/tree/master/lib/gitlab/ci/templates

### Other
.gitlab-ci.yml 驗證工具
https://gitlab.example.com.tw/group/project/-/ci/lint

## Gitlab CI/CD

### Variables


Set variable



Ref: https://ithelp.ithome.com.tw/articles/10218938

Ref: https://docs.gitlab.com/ee/ci/yaml/