DevOps Classroom notes 08/Sep/2025

Github Actions contd

• Pipeline
  • When to run (on)
  • Where to run (jobs => runs_on)
  • what to run (jobs)
• Github jobs execute on runners (servers on which jobs will be executed.) .
• Runners are of two types
  • Github hosted Runners
    • Gives you options to run the following
      • Windows
      • linux
      • mac
    • These will have specific images
    • Github gives us
      • Standard Runners
        • Linux (Ubuntu): 2 vCPUs, 7 GB RAM, 14 GB SSD storage.
        • Windows: 2 vCPUs, 7 GB RAM, 14 GB SSD storage.
        • macOS (Intel): 4 vCPUs, 14 GB RAM, 14 GB SSD storage.
        • macOS (Apple Silicon – M1/M2): 3 vCPUs (M1), 7 GB RAM, 14 GB SSD storage. (Note: A 5-vCPU macOS M2 runner is also available in public preview).
      • Large Runners
  • Self hosted Runners
  • Containers

jobs

• Jobs are collection of job elements which can be run in parallel or sequence
• A job runs on a runner
• job is made of steps
• Each step can be a
  • low level command: are used with run statement
  • reusable action: are used with withstatement. Github has a market place for actions

Lets try to build a java application

• SPring petclinic is a popular application developed in spring boot
• This application requires jdk 21 to run and maven to build it.
• the command to build the code

mvn package

• Java installation steps

sudo apt update
sudo apt install openjdk-21-jdk -y

• Maven setup

cd /tmp
wget https://dlcdn.apache.org/maven/maven-3/3.9.11/binaries/apache-maven-3.9.11-bin.tar.gz
sudo tar xf apache-maven-3.9.11-bin.tar.gz -C /opt
# open maven.sh
sudo nano /etc/profile.d/maven.sh
# copy the following lines
export JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64
export M3_HOME=/opt/apache-maven-3.9.11
export MAVEN_HOME=/opt/apache-maven-3.9.11
export PATH=${M3_HOME}/bin:${PATH}

sudo chmod +x /etc/profile.d/maven.sh
source /etc/profile.d/maven.sh
mvn -version

• Clone the spring petclinic

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

• The workflow

---
on:
    push:
      branches:
        - main
    workflow_dispatch: #manual trigger

jobs:
    maven:
        runs-on: [ 'ubuntu-latest' ]
        steps:
          - name: checkout the code
            uses: actions/checkout@v4
          - name: build code
            run: mvn package