Migrating from Jenkins to Actions

Introduction

Jenkins and Actions both allow you to create workflows that automatically build, test, publish, release, and deploy code. Jenkins and Actions share some similarities in workflow configuration:

• Jenkins creates workflows using Declarative Pipelines, which are similar to Actions workflow files.
• Jenkins uses stages to run a collection of steps, while Actions uses jobs to group one or more steps or individual commands.
• Jenkins and Actions support container-based builds. For more information, see Creating a Docker container action.
• Steps or tasks can be reused and shared with the community.

For more information, see Understanding Actions.

Key differences

• Jenkins has two types of syntax for creating pipelines: Declarative Pipeline and Scripted Pipeline. Actions uses YAML to create workflows and configuration files. For more information, see Workflow syntax for Actions.
• Jenkins deployments are typically self-hosted, with users maintaining the servers in their own data centers. Actions offers a hybrid cloud approach by hosting its own runners that you can use to run jobs, while also supporting self-hosted runners. For more information, see About self-hosted runners.

Comparing capabilities

Distributing your builds

Jenkins lets you send builds to a single build agent, or you can distribute them across multiple agents. You can also classify these agents according to various attributes, such as operating system types.

Similarly, Actions can send jobs to -hosted or self-hosted runners, and you can use labels to classify runners according to various attributes. For more information, see Understanding Actions and About self-hosted runners.

Using sections to organize pipelines

Jenkins splits its Declarative Pipelines into multiple sections. Similarly, Actions organizes its workflows into separate sections. The table below compares Jenkins sections with the Actions workflow.

Using directives

Jenkins uses directives to manage Declarative Pipelines. These directives define the characteristics of your workflow and how it will execute. The table below demonstrates how these directives map to concepts within Actions.

Using sequential stages

Parallel job processing

Jenkins can run the stages and steps in parallel, while Actions currently only runs jobs in parallel.

Matrix

Both Actions and Jenkins let you use a matrix to define various system combinations.

Using steps to execute tasks

Jenkins groups steps together in stages. Each of these steps can be a script, function, or command, among others. Similarly, Actions uses jobs to execute specific groups of steps.

Examples of common tasks

Scheduling a pipeline to run with cron

Jenkins pipeline with cron

pipeline {
  agent any
  triggers {
    cron('H/15 * * * 1-5')
  }
}

Actions workflow with cron

on:
  schedule:
    - cron: '*/15 * * * 1-5'

Configuring environment variables in a pipeline

Jenkins pipeline with an environment variable

pipeline {
  agent any
  environment {
    MAVEN_PATH = '/usr/local/maven'
  }
}

Actions workflow with an environment variable

jobs:
  maven-build:
    env:
      MAVEN_PATH: '/usr/local/maven'

Building from upstream projects

Jenkins pipeline that builds from an upstream project

pipeline {
  triggers {
    upstream(
      upstreamProjects: 'job1,job2',
      threshold: hudson.model.Result.SUCCESS
    )
  }
}

Actions workflow that builds from an upstream project

jobs:
  job1:
  job2:
    needs: job1
  job3:
    needs: [job1, job2]

Building with multiple operating systems

Jenkins pipeline that builds with multiple operating systems

pipeline {
  agent none
  stages {
    stage('Run Tests') {
      matrix {
        axes {
          axis {
            name: 'PLATFORM'
            values: 'macos', 'linux'
          }
        }
        agent { label "${PLATFORM}" }
        stages {
          stage('test') {
            tools { nodejs "node-20" }
            steps {
              dir("scripts/myapp") {
                sh(script: "npm install -g bats")
                sh(script: "bats tests")
              }
            }
          }
        }
      }
    }
  }
}

Actions workflow that builds with multiple operating systems

name: demo-workflow
on:
  push:
jobs:
  test:
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [macos-latest, ubuntu-latest]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm install -g bats
      - run: bats tests
        working-directory: ./scripts/myapp