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Hello World

This document describes how to get started with a basic build of your Linux, Android, Windows, or macOS project on CircleCI 2.x after you sign up.

Echo hello world on Linux

This example adds a job called build that spins up a container running a pre-built CircleCI Docker image for Node. Then, it runs a simple echo command. To get started, complete the following steps:

  1. Create a directory called .circleci in the root directory of your local GitHub or Bitbucket code repository.

  2. Create a config.yml file with the following lines (if you are using CircleCI Server, use version: 2.0 configuration): 
    version: 2.1
jobs:
  build:
    docker:
      - image: cimg/node:14.10.1 # the primary container, where your job's commands are run
        auth:
          username: mydockerhub-user
          password: $DOCKERHUB_PASSWORD  # context / project UI env-var reference
    steps:
      - checkout # check out the code in the project directory
      - run: echo "hello world" # run the `echo` command

  3. Commit and push the changes.

  4. Go to the Projects page in the CircleCI app, click the Add Projects button, then click the Set Up Project button next to your project. If you don’t see your project, make sure you have selected the associated Org. See the Org Switching section below for tips.

  5. Click the Start Building button to trigger your first build.

The Workflows page appears with your build job and prints Hello World to the console.

Note: If you get a No Config Found error, it may be that you used .yaml file extension. Be sure to use .yml file extension to resolve this error.

CircleCI runs each job in a separate container or VM. That is, each time your job runs, CircleCI spins up a container or VM to run the job in.

Refer to the Node.js - JavaScript Tutorial for a sample project.

Hello world for Android

Using the basic ideas from the Linux example above, you can add a job that uses the docker executor with a pre-built Android image in the same config.yml file as follows:

jobs:
  build-android:
    docker:
      - image: circleci/android:api-25-alpha
        auth:
          username: mydockerhub-user
          password: $DOCKERHUB_PASSWORD  # context / project UI env-var reference

See the Android Language Guide for details and a sample project.

Hello world for macOS

The macOS executor is not currently available on self-hosted installations of CircleCI Server

Using the basics from the Linux and Android examples above, you can add a job that uses the macos executor and a supported version of Xcode as follows:

jobs:
  build-macos:
    macos:
      xcode: 11.3.0

Refer to the Hello World on MacOS document for more information and a sample project.

Hello world for Windows

Using the basics from the Linux, Android, and macOS examples above, you can add a job that uses the windows executor (Windows Server 2019) as follows. Notice the Cloud version of this requires the use of version:2.1 config, and orbs:

version: 2.1 # Use version 2.1 to enable orb usage.

orbs:
  win: circleci/windows@2.2.0 # The Windows orb give you everything you need to start using the Windows executor.

jobs:
  build: # name of your job
    executor:
      name: win/default # executor type
      size: "medium" # resource class, can be "medium", "large", "xlarge", "2xlarge", defaults to "medium" if not specified

    steps:
      # Commands are run in a Windows virtual machine environment
      - checkout
      - run: Write-Host 'Hello, Windows'

version: 2

jobs:
  build: # name of your job
    machine:
      image: windows-default # Windows machine image
    resource_class: windows.medium
    steps:
      # Commands are run in a Windows virtual machine environment
        - checkout
        - run: Write-Host 'Hello, Windows'

Note: For Windows builds, some setup and prerequisites are different. Please refer to our Hello World on Windows.

More about using and authoring orbs

Orbs are a great way to simplify your config or re-use config across your projects, by referencing packages of config in the CircleCI Orbs Registry.

Following / unfollowing projects

You automatically follow any new project that you push to, subscribing you to email notifications and adding the project to your dashboard. You can also manually follow or stop following a project by selecting your organization in the CircleCI application (as detailed below), clicking “Projects” in the sidebar, and then clicking the button next to the project you want to follow or stop following.

Org switching

In the top left, you will find the Org switcher.

Switch Organization Menu

Switch Organization Menu

If you do not see your project and it is not currently building on CircleCI, check your org in the top left corner of the CircleCI application. For example, if the top left shows your user my-user, only GitHub projects belonging to my-user will be available under Add Projects. If you want to build the GitHub project your-org/project, you must select your-org on the application Switch Organization menu.

Next steps

  • See the Concepts document for a summary of 2.0 configuration and the hierarchy of top-level keys in a .circleci/config.yml file.

  • Refer to the Workflows document for examples of orchestrating job runs with concurrent, sequential, scheduled, and manual approval workflows.

  • Find complete reference information for all keys and pre-built Docker images in the Configuring CircleCI and CircleCI Images documentation, respectively.