DevOps Classroom notes 03/Dec/2024

Pipeline as Code

• Pipeline as Code is about representing the CI/CD pipeline in a format that can be stored in version control system
• Examples:
  • Jenkins: Jenkinsfile
    • Scripted Pipeline
    • Declarative Pipeline
  • Azure DevOps: azure-pipelines.yaml
  • Github Actions: .github\*.yaml
• Branch wise pipelines

Azure DevOps Pipelines

• To create pipeline we need to write a YAML file
• filename can be anything but azure-pipelines.yaml is most widely used
• This YAML has a schema (structure)
  
• YAML Pipelines can be created in visual studio code (install extension) or in azure devops pipelines section

Agents

• Azure DevOps Agents represent where we can run the pipeline
• Agents are of two types
  • Microsoft Hosted
  • Self Hosted
• Complete pipeline can be run on a single agent or we can have agent per stage or agent per job
• Agents docs

Steps/Tasks

• This is smallest unit of work where you execute the pipeline steps
• On a broader note we have two options
  • task:
    • These are reusable activities published by azure devops or other communities
    • We can also create a custom azure devops task (it needs to written in javascript over nodejs)
    • Predefined task list
    • Community Based : Azure DevOps Market place
  • other (script/command/….):
    • These are low level activities where we mostly run the commands directly

Azure DevOps YAML Schema

• documentation
• Pipeline schema

Authoring Pipelins

• Watch classroom video for instructions
• First sample

---
pool:
  vmImage: ubuntu-24.04
trigger:
  - main
stages:
  - stage: buildstage
    jobs:
      - job: buildjob
        steps:
          - task: Maven@4
            inputs:
              mavenPomFile: pom.xml
              goals: validate
              jdkVersionOption: '1.17'