Publish to GitHub Packages

Use GitHub Actions to publish your project to a Docker image.

Step 1: Create the workflow file

Welcome to "Publish packages"! 👋

First, take a moment to examine the image below. It shows the relationship between continuous integration, continuous delivery and continuous deployment.

Continuous integration (CI) is a practice where developers integrate tested code into a shared branch several times per day. Continuous delivery (CD) is the next phase of continuous integration (CI), where we deploy our changes to the world.

Docker is an engine that allows you to run containers. Containers are packages of software that can run reliably in different environments. Containers include everything needed to run the application. Containers are lightweight in comparison to virtual machines. A dockerfile is a text document that contains all the commands and instructions necessary to build a Docker Image. A Docker image is an executable package comprised of code, dependencies, libraries, a runtime, environment variables, and configuration files. A Docker container is a runtime instance of a Docker Image.

We'll start by creating the workflow file to publish a Docker image to GitHub Packages.

⌨️ Activity: Create the workflow file

1. Open a new browser tab, and work on the steps in your second tab while you read the instructions in this tab.
2. Open the pull request I made for you from the cd branch.
3. Add a new file at .github/workflows/publish.yml.
4. Add the following to the publish.yml file:

   name: Publish to Docker
   on:
     push:
       branches:
         - main
   jobs:
     publish:
       runs-on: ubuntu-latest
       steps:
         - uses: actions/checkout@v2
         # Add your test steps here if needed...
         - name: Build container
           uses: docker/build-push-action@v1
           with:
             username: YOURNAME
             password: ${{ secrets.GITHUB_TOKEN }}
             registry: docker.pkg.github.com
             repository: YOURNAME/publish-packages/game
             tag_with_sha: true

5. Replace YOURNAME with your username.
6. Commit your changes.
7. Wait about 20 seconds then refresh this page for the next step.

Step 2: Add a Dockerfile

You created a publishing workflow! 🎉

We will add a Dockerfile in this pull request. The Dockerfile contains a set of instructions that get stored in a Docker Image. If you'd like, you can learn more about Dockerfiles.

⌨️ Activity: Add a Dockerfile

1. In the cd branch, create Dockerfile at the project root and include:

   FROM nginx:1.17
   COPY . /usr/share/nginx/html

2. Commit your changes.
3. Wait about 20 seconds then refresh this page for the next step.

Step 3: Merge your pull request

Let's get publishing! ❤️

You can now merge your pull request!

⌨️ Activity: Merge your pull request

1. Click Merge pull request.
2. Delete the branch cd (optional).
3. Wait about 20 seconds then refresh this page for the next step.

Step 4: Pull your image

Now things are running! ✨

Whoa, now things are running! This may take a few minutes. This might take a tiny amount of time, so grab your popcorn 🍿 and wait for the build to finish before moving on.

To pull the Docker image, we need to log into Docker first.

Before we can use this Docker image, you will need to generate a personal access token that contains the following permissions:

• repo (all)
• write:packages
• read:packages

We will use this token to log in to Docker, and authenticate with the package.

1. Open your terminal (Bash or Git Bash recommended)
2. Use the following command to log in:

   docker login docker.pkg.github.com -u USERNAME -p TOKEN
   

3. Replace USERNAME with your GitHub username
4. Replace TOKEN with the Personal Access Token you just created
5. Press Enter

If everything went well, 🤞 you should see Login Succeeded in your terminal.

⌨️ Activity: Pull your image

1. Copy and paste the pull command from the package instructions into your terminal. It should look something like this:
   • docker pull docker.pkg.github.com/YOURNAME/js-build/tic-tac-toe:f29
2. Press Enter.
3. You should see output indicating that the pull was successful, like Status: Downloaded newer image for docker.
4. We can't automatically verify this step for you, so please continue on to the next step below!

Step 5: Run your image

Nicely done grabbing your Docker image! ☺️

Let's trying running it.

⌨️ Activity: Run your image

1. Find your image information by typing Docker image ls.
2. Use the following command to run a container from your image:

   docker run -d -it --rm -p 8080:80 --name ttt <YOUR_IMAGE_NAME:TAG>
   

3. Replace YOUR_IMAGE_NAME with your image name under the REPOSITORY column.
4. Replace TAG with the image tag under the TAG column
5. Press Enter.
6. If everything went well, you will see hash value as output on your screen.
7. We can't automatically verify this step for you, so please continue on to the next step below!

Finish

Congratulations friend, you've completed this course!

Here's a recap of all the tasks you've accomplished in your repository:

• You wrote a workflow that sends a code through a continuous delivery pipeline.
• You built a fully deployable artifact.
• You did so using GitHub Actions and GitHub Packages!

What's next?

• Publish your own packages from your projects.
• We'd love to hear what you thought of this course in our discussion board.
• Take another GitHub Skills course.
• Read the GitHub Getting Started docs.
• To find projects to contribute to, check out GitHub Explore.

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Get help: Post in our discussion board • Review the GitHub status page

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