Migrating from Travis CI to GitHub Actions

Einführung

This guide helps you migrate from Travis CI to GitHub Actions. It compares their concepts and syntax, describes the similarities, and demonstrates their different approaches to common tasks.

Before you start

Before starting your migration to GitHub Actions, it would be useful to become familiar with how it works:

• For a quick example that demonstrates a GitHub Actions job, see "Quickstart for GitHub Actions."
• To learn the essential GitHub Actions concepts, see "Introduction to GitHub Actions."

Comparing job execution

To give you control over when CI tasks are executed, a GitHub Actions workflow uses jobs that run in parallel by default. Each job contains steps that are executed in a sequence that you define. If you need to run setup and cleanup actions for a job, you can define steps in each job to perform these.

Key similarities

GitHub Actions and Travis CI share certain similarities, and understanding these ahead of time can help smooth the migration process.

Using YAML syntax

Travis CI and GitHub Actions both use YAML to create jobs and workflows, and these files are stored in the code's repository. For more information on how GitHub Actions uses YAML, see "Creating a workflow file."

Custom environment variables

Travis CI lets you set environment variables and share them between stages. Similarly, GitHub Actions lets you define environment variables for a step, job, or workflow. For more information, see "Environment variables."

Standard-Umgebungsvariablen

Travis CI and GitHub Actions both include default environment variables that you can use in your YAML files. For GitHub Actions, you can see these listed in "Default environment variables."

Parallele Verarbeitungvon Jobs

Travis CI can use stages to run jobs in parallel. Similarly, GitHub Actions runs jobs in parallel. For more information, see "Creating dependent jobs."

Status badges

Travis CI and GitHub Actions both support status badges, which let you indicate whether a build is passing or failing. For more information, see "Adding a workflow status badge to your repository."

Using a build matrix

Travis CI and GitHub Actions both support a build matrix, allowing you to perform testing using combinations of operating systems and software packages. For more information, see "Using a build matrix."

Below is an example comparing the syntax for each system:

matrix:
  include:
    - rvm: 2.5
    - rvm: 2.6.3

jobs:
  build:
    strategy:
      matrix:
        ruby: [2.5, 2.6.3]

Targeting specific branches

Travis CI and GitHub Actions both allow you to target your CI to a specific branch. Weitere Informationen findest Du unter „Workflow-Syntax für GitHub-Aktionen."

Nachfolgend ein Beispiel für die Syntax in jedem System:

branches:
  only:
    - main
    - 'mona/octocat'

on:
  push:
    branches:
      - main
      - 'mona/octocat'

Checking out submodules

Travis CI and GitHub Actions both allow you to control whether submodules are included in the repository clone.

Nachfolgend ein Beispiel für die Syntax in jedem System:

git:
  submodules: false

- uses: actions/checkout@v2
  with:
    submodules: false

Using environment variables in a matrix

Travis CI and GitHub Actions can both add custom environment variables to a test matrix, which allows you to refer to the variable in a later step.

In GitHub Actions, you can use the include key to add custom environment variables to a matrix. In this example, the matrix entries for node-version are each configured to use different values for the site and datacenter environment variables. The Echo site details step then uses env: ${{ matrix.env }} to refer to the custom variables:

name: Node.js CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
       include:
         - node-version: 10.x
           site: "prod"
           datacenter: "site-a"
         - node-version: 12.x
           site: "dev"
           datacenter: "site-b"
    steps:
      - name: Echo site details
        env:
          SITE: ${{ matrix.site }}
          DATACENTER: ${{ matrix.datacenter }}
        run: echo $SITE $DATACENTER

Key features in GitHub Actions

When migrating from Travis CI, consider the following key features in GitHub Actions:

Storing secrets

GitHub Actions allows you to store secrets and reference them in your jobs. GitHub Actions organizations can limit which repositories can access organization secrets. For more information, see "Encrypted secrets."

Sharing files between jobs and workflows

GitHub Actions includes integrated support for artifact storage, allowing you to share files between jobs in a workflow. You can also save the resulting files and share them with other workflows. For more information, see "Sharing data between jobs."

Deinen eigenen Runner hosten

If your jobs require specific hardware or software, GitHub Actions allows you to host your own runners and send your jobs to them for processing. GitHub Actions also lets you use policies to control how these runners are accessed, granting access at the organization or repository level. For more information, see "Hosting your own runners."

Concurrent jobs and execution time

The concurrent jobs and workflow execution times in GitHub Actions can vary depending on your GitHub plan. For more information, see "Usage limits, billing, and administration."

Using different languages in GitHub Actions

When working with different languages in GitHub Actions, you can create a step in your job to set up your language dependencies. For more information about working with a particular language, see the specific guide:

• Building and testing Node.js or Python
• Building and testing PowerShell
• Java bauen und testen mit Maven
• Java bauen und testen mit Gradle
• Java bauen und testen mit Ant

Executing scripts

GitHub Actions can use run steps to run scripts or shell commands. To use a particular shell, you can specify the shell type when providing the path to the script. Weitere Informationen findest Du unter „Workflow-Syntax für GitHub Actions“.

Ein Beispiel:

steps:
  - name: Run build script
    run: ./.github/scripts/build.sh
    shell: bash

Error handling in GitHub Actions

When migrating to GitHub Actions, there are different approaches to error handling that you might need to be aware of.

Script error handling

GitHub Actions stops a job immediately if one of the steps returns an error code. Weitere Informationen findest Du unter „Workflow-Syntax für GitHub Actions“.

Job error handling

GitHub Actions uses if conditionals to execute jobs or steps in certain situations. For example, you can run a step when another step results in a failure(). Weitere Informationen findest Du unter „Workflow-Syntax für GitHub Actions“. You can also use continue-on-error to prevent a workflow run from stopping when a job fails.

Migrating syntax for conditionals and expressions

To run jobs under conditional expressions, Travis CI and GitHub Actions share a similar if condition syntax. GitHub Actions lets you use the if conditional to prevent a job or step from running unless a condition is met. For more information, see "Expressions."

This example demonstrates how an if conditional can control whether a step is executed:

jobs:
  conditional:
    runs-on: ubuntu-latest
    steps:
      - run: echo "This step runs with str equals 'ABC' and num equals 123"
        if: env.str == 'ABC' && env.num == 123

Migrating phases to steps

Where Travis CI uses phases to run steps, GitHub Actions has steps which execute actions. You can find prebuilt actions in the GitHub Marketplace, or you can create your own actions. Weitere Informationen findest Du unter „Aktionen bauen“.

Nachfolgend ein Beispiel für die Syntax in jedem System:

language: python
python:
  - "3.7"

script:
  - python script.py

jobs:
  run_python:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/setup-python@v2
        with:
          python-version: '3.7'
          architecture: 'x64'
      - run: python script.py

Abhängigkeiten „cachen“ (zwischenspeichern)

Travis CI and GitHub Actions let you manually cache dependencies for later reuse. This example demonstrates the cache syntax for each system.

language: node_js
cache: npm

- name: Cache node modules
  uses: actions/cache@v2
  with:
    path: ~/.npm
    key: v1-npm-deps-${{ hashFiles('**/package-lock.json') }}
    restore-keys: v1-npm-deps-

GitHub Actions caching is only applicable to GitHub-hosted runners. Weitere Informationen findest Du unter „Abhängigkeiten zur Beschleunigung von Workflows im Cache zwischenspeichern“.

Beispiele für häufige Aufgaben

This section compares how GitHub Actions and Travis CI perform common tasks.

Configuring environment variables

You can create custom environment variables in a GitHub Actions job. Ein Beispiel:

env:
  - MAVEN_PATH="/usr/local/maven"

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

Building with Node.js

install:
  - npm install
script:
  - npm run build
  - npm test

name: Node.js CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Use Node.js
        uses: actions/setup-node@v2
        with:
          node-version: '12.x'
      - run: npm install
      - run: npm run build
      - run: npm test

Nächste Schritte:

To continue learning about the main features of GitHub Actions, see "Learn GitHub Actions."