Hello CI World

Hello CI World#

Overview

Teaching: 5 min | Exercises: 10 min

Questions

  • How do I run a simple GitHub Actions job?

Objectives

  • Add CI/CD to a new project.

Adding CI/CD to a project#

Let’s start with a project that doesn’t have any CI/CD configured. We’ll use the 2026-08-10-cicd-github-examples repository for this example. Create a fork of the repository and clone it to your local session:

GITHUB_USER=<your-github-username>
git clone https://github.com/$GITHUB_USER/2026-08-10-cicd-github-examples.git

Permissions for remote repository

Be sure to have the credentials to write in the remote repository. If you don’t, you won’t be able to push your changes and trigger the CI/CD job.

Authenticate to GitHub from the command line, either with SSH keys or with the gh command line interface (see caching your GitHub credentials in git)

The first thing we’ll do is create a .github/workflows/main.yml file in the project.

cd 2026-08-10-cicd-github-examples/
mkdir -p .github/workflows
touch .github/workflows/main.yml

Open .github/workflows/main.yml with your favorite editor and add the following

name: example
on: push
jobs:
  greeting:
    runs-on: ubuntu-latest
    steps:
      - run: echo hello world

Working on Jupyter Hub

If you are following the tutorial on the Jupyter Hub instance, hidden files are not displayed by default. Therefore, you can’t see the .github directory and its contents outside the terminal.

A trick to use the Jupyter Hub file browser to edit the .github/workflows/main.yml file is to create a symbolic link to it in your home directory. You can do this with the following command:

ln -s $PWD/.github/workflows $PWD/workflows

However, you can also edit the file directly from the terminal using your favorite text editor (e.g. nano, vim, emacs, etc.)

Run GitHub Actions#

Now, let’s see it in action!

We’ve created the .github/workflows/main.yml file, but it’s not yet on GitHub. We’ll push these changes to GitHub so that it can run our job.

Since we’re adding a new feature (Actions) to our project, we’ll work in a feature branch. This is just a human-friendly named branch to indicate that it’s adding a new feature.

git add .github/workflows/main.yml
git commit -m "my first actions"
git push origin main

And that’s it! You’ve successfully run your CI/CD job, and you can view the output. You just have to navigate to the GitHub webpage for your repository and hit the Actions tab, where you will find details of your job (status, output,…).

From this page, click through until you can find the output for the successful job run .

Key Points

  • Creating .github/workflows/main.yml is the first step to salvation.

  • Pipelines are made of jobs with steps.