Github Actions

Runners

• We need a place to execute the workflow (virtual or physical system)
• At a highlevel, we have two choices
  • Github hosted runners
  • Self hosted runners

Github hosted Runners

• These runners are provided by Github
• Every Github hosted runner is created as a new virtual machine with choice of
  • Ubuntu Linux
  • Windows Servers
  • macos
• When executing workflows on this runners a simple declaration suchss runs-on: ubuntu-latest
• Refer Here for the available images as SBOM . Sample for ubuntu 24.04
• Apart from existing softwares already installed we can add additonal softwares if required

jobs:
  update-env:
    runs-on: ubuntu-24.04
    steps:
      - name: Install packages
        run: |
          sudo apt update
          sudo apt install <package-name> -y

Self hosted Runners

• A runner can be mapped at
  • Repository Level
  • Organization Level
  • Enterprise
• Refer Here for official docs on self hosted runners

Autoscaling Self-Hosted Runners

• If you have access to k8s cluster, you can setup self-hosted runner orchestration and scaling via Actions Runner Controllers (ARC).
• ARC works as k8s operator to create scale sets
• Scale sets are runners that are controlled by ARC and can have jobs assigned to them from GitHUb
• Setting up Actions Runner Controller on K8s
• for runners on aws Refer Here

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Finding Github Actions from market place

Core Github Actions

• actions/checkout
• actions/setup-node
• actions/setup-python
• actions/setup-java
• actions/setup-go
• actions/cache
• actions/upload-artifacts
• actions/download-artifacts
• actions/github-script

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Create a workflow to build, test java application

• Workflow syntax
• Watch classroom recording
• Exercise: Try publishing the test results for spring petclinic