LetsDevOps: GitLab YAML Pipeline Tutorial for Beginners. Setup Multi Stage/Job CI/CD Pipeline.

Introduction

In this blog will learn basic of GitLab YAML pipeline and further we will learn to setup the CI/CD.

Demo Use Case

1. Setup Multi Stage/Multi Job Pipeline

2. Setup Pipeline with variables

3. Build Visual Studio Project

What is YAML

YAML is a human-readable data-serialization language and it helps to configure pipeline as a Code.

Indentation is very important in YAML.

GitLab YAML Pipeline

In GitLab, YAML Pipelines helps to setup Continuous Integration/ Continuous Deployment (CI/CD).

GitLab YAML Pipeline Structure

Hierarchy of YAML Pipeline File

stages:    
  - build
  - test
  - deploy

build-job:     
  stage: build
  tags:
    - "windows"
  script:
    -  write-host "I am in Build Stage"
test-job:      
  stage: test
  tags:
    - "windows"
  script:
    -  write-host "I am in Test Stage"
deploy-job: 
  stage: deploy
  tags:
    - "windows"
  script:
    -  write-host "I am in Deploy Stage"

Component of GitLab YAML Pipeline

workflow

Workflow helps to control when and what pipeline to run.

workflow:
    rules:
        - if: $CI_COMMIT_BRANCH == "master"
          changes:
            - <Project Path>

variables

Here we can define all the variables which can be used during the job execution.

variables:
   BUILD_PROJECT:"https://example.com/"
   BUILD_SITE:"https://example.com/"
   MSBUILD_PATH:'<Path>\v4.0.30319\MSBuild.exe'

before_script

This helps to execute any script you want execute before the Job script executes.

build-job:       # This job runs in the build stage, which runs first.
  stage: build
  before_script:
    - echo "Set the Deploy Version"

stages

With stages we define list of stage which will be part of the CI/CD.

This also define order of execution.

stages:  # List of stages for jobs, and their order of execution
  - build
  - test
  - deploy

Job<stage>

We can defined multiple jobs and each job must be part of the Stage.

build-job:       # This job runs in the build stage, which runs first.
  stage: build
  script:
    -  write-host "I am in Build Stage"

Script

Here we define list of command for Runner to Execute.

build-job:       # This job runs in the build stage, which runs first.
  stage: build
  tags:
    - "windows"
  script:
    -  write-host "I am in Build Stage"
    - msbuild 

Schema of YAML

variables: # Define List of Variables
stages: # Define List of Stages
build-job: # Define Job
  stage: build #Define which Stage 
  tags:
    - "windows" # Define Runner Tag
  script:
    -  write-host #Define command to execute 

Demo

Use Case 1: Setup Multi Stage/Multi Job Pipeline

stages:    
  - build
  - test
  - deploy

build-job:     
  stage: build
  tags:
    - windows-demo
  script:
    - write-host "Build Application"
    
run-job:   
  stage: build  
  tags:
    - windows-demo
  script:
    - write-host "I am in run Job"
    
test-job:   
  stage: test 
  tags:
    - windows-demo
  script:
    - write-host "Run Test"

Use Case 2: Setup Pipeline with variables

variables:
  DEPLOY_PATH: 'C:\DeployIIS' 
stages:    
  - build
  - package
  - deploy

build-job:     
  stage: build
  tags:
    - windows-runner
  script:
    - Write-host "Deployment Path is $DEPLOY_PATH"

Use Case 3: Build Visual Studio Project

stages:    
  - build
  - test

build-job:     
  stage: build
  tags:
    - windows-demo
  script:
    - dotnet build $CI_PROJECT_DIR\BuildNugetPackage.sln /p:Configuration="Release"

Setup Runner

Learn to setup GitLab Runner.

Demo

Reference:

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