DevOps Classroom notes 21/Oct/2023

Building and Packaging Java Projects using a Maven

Compilation: Process of
- checks for errors in code
- converts to desired language (Byte code/machine code)
Packaging:
- Combining compiled code into some packaging format
  - java: jar/war/ear
  - dotnet: dll/exe
Dependencies: will be downloaded
- java: maven/gradle
- dotnet: nuget
- python: pip
- nodejs: npm
Maven: combines dependency resolution, compilation, unit test executions, packaging
Maven expects a file called as pom.xml
Steps:
- Get the latest code
- Pre-requisites:
  - jdk version
  - maven
- Execute mvn <goal>
  - compile
  - test
  - package
- In our case we will be using mvn package

sudo apt update
sudo apt install openjdk-17-jdk -y
sudo apt install maven -y
git --version
java -version
mvn --version

* Build steps

cd ~
git clone https://github.com/spring-projects/spring-petclinic.git
cd spring-petclinic
mvn package

Azure DevOps has two ways of building pipelines
- Classic Pipelines: We rely on user interface
  - Drawback:
    - History will be missing
  - Advantages:
    - Easy to start
- Azure Pipelines YAML: Pipeline as Code. We will define pipelines steps in a file azure-pipelines.yaml and add it to the version control system (git)
  - Advantage:
    - History will be maintained
  - Disadvantage:
    - Learning curve for writing pipeline
Azure DevOps has agents: Agent is where the build is executed. There are two types of agents
- Microsoft Hosted agents: These are machines which will be created on demand by Azure DevOps and will be delete upon build completion.
- Self Hosted Agents: These are machines managed by us, we add these machines as agents to Azure DevOps.
Azure DevOps plans
- Free:
  - 1 Free Microsoft-hosted CI/CD (1800 minutes/month)
  - 1 Free Self-Hosted CI/CD
  - Azure Source Repos => free
  - Azure Artifacts 2 GB