Exercise: Code with Codespaces

@dvmpr

Code with Codespaces

👋 Hey there @dvmpr! Welcome to your Skills exercise!

Let's create a pre-configured environment to simplify development!

✨ This is an interactive, hands-on GitHub Skills exercise!

As you complete each step, I’ll leave updates in the comments:

✅ Check your work and guide you forward
💡 Share helpful tips and resources
🚀 Celebrate your progress and completion

Let’s get started - good luck and have fun!

_{— Mona}

_{If you encounter any issues along the way please report them here.}

Step 1: Start a codespace and push some code

What's the big deal about Codespaces?

A codespace is a development environment hosted in the cloud, defined by configuration files in your repository. This creates a repeatable development environment tailored specifically to the project that simplifies developer onboarding and avoids the famous phrase "It works on my machine!" 😎

Each codespace follows the Dev Container specification and is hosted by GitHub as a Docker container.

But don't worry! You don't need to know Docker or even have it installed on your machine!

Tip

Since the Dev Container configuration is part of the repository, you can also use it locally with your own Docker host. Nice!

A Codespace has several advantages/features compared to local development. To name a few:

Start a codespace directly from the repository page.
Develop in the browser. No IDE installation required.
- Option to use a local install of VS Code to link to the remote Codespace.
Preconfigure everything you need to run the project:
- Add features to install common development needs.
- Run scripts at various steps of the codespace lifecycle (e.g install python/npm packages).
- Setup VS Code settings and extensions to match the project needs.
Fast internet access (since the container is in the datacenter).

Tip

Codespaces are even useful in short-lived situations like reviewing a pull request. No need to verify you have the right setup to test out the incoming code changes.

Let's get started! We'll start up a Codespace, run the application, make a change, and push it. Like normal development! 🤓

⌨️ Activity: Start a codespace

Open a second tab and navigate to this repository. Ensure you are on the Code tab.
Above the files list on the right, click the green <> Code button.
Select the Codespaces tab and click the Create codespace on main button. A new window will open running VS Code and it will connect to the remote Codespace. Wait a few minutes for the codespace to be created.
Look in the bottom left of the VS Code window see the remote connection.

Tip

GitHub uses the universal Codespace image if the repository doesn't include a configuration. It includes several useful and commonly used tools.

⌨️ Activity: Run the application

Ensure you are in the VS Code Codespace.
In the left sidebar, select the file Explorer tab and open the file src/hello.py.
In the lower panel, select the TERMINAL tab.
Paste the following command in the Codespace's remote terminal to show the installed versions of several tools. Note the versions for comparison later.
```
node --version
dotnet --version
python --version
gh --version
```
Paste the following command to run the Python program in the Codespace's remote terminal.
```
python src/hello.py
```

⌨️ Activity: Push changes to your repository from the codespace

Replace the src/hello.py file contents with the following and save the file.
```
print("Hello World!")
```
With the message updated, commit the change and push it to GitHub. Use VS Code's source control tools or the below terminal commands.
```
git add 'src/hello.py'
git commit -m 'fix: incomplete hello message'
git push
```
(optional) Back in your web browser, open the src/hello.py file to to verify the change was updated.
With the the change pushed to GitHub, Mona will begin checking your work. Give her a moment to provide feedback and the next learning steps.

Step 1 - Passed ✅

Status	Description
✅ - Pass	Hello message fixed in hello.py

🎉🎉🎉 Nice work! Everything is perfect! 🎉🎉🎉
Preparing content for step 2! One moment... 🤓

Step 2: Use a custom image in your codespace

The repository didn't specify any configuration for the codespace we just created, so GitHub used a default Docker image. While this is very useful, it won't be consistent and it doesn't version lock our runtime environment. Specifying the configuration is important to keep the development environment repeatable.

Let's do that now by providing a specific docker container image.

How to configure a Codespace?

Configuration is provided directly in the repository via the .devcontainer/devcontainer.json. You can even add multiple configurations!

Let's create this file and set a few of the most common settings. For other options like setting configuring VS Code, forwarding ports, and running lifecycle scripts, see the Codespaces documentation on GitHub.

⌨️ Activity: Customize the codespace

Ensure you are in the VS Code Codespace.
Use the VS Code file explorer to create the configuration file.
```
.devcontainer/devcontainer.json
```
Alternately, run the below terminal command to create it.
```
mkdir -p .devcontainer
touch .devcontainer/devcontainer.json
```
Open the .devcontainer/devcontainer.json file and add the following content. Let's start with a basic image.
```
{
  "name": "Basic Dev Environment",
  "image": "mcr.microsoft.com/devcontainers/base:debian"
}
```
💡 Tip: The name is optional but it will help identify the configuration when creating a codespace on GitHub, if there are multiple options.
After saving, VS Code likely popped up a notification that it detected a configuration change. You can Accept that option to rebuild the development container or manually use the Command Palette (CTRL+Shift+P) and run the command Codespaces: Rebuild Container. Select the Rebuild option. A full build is not necessary.
Wait a few minutes for the Codespace to rebuild and VS Code to reconnect.
Expand the lower panel and select the TERMINAL tab.
Use the following command to check the tool versions again. Notice that none are installed now!
```
node --version
dotnet --version
python --version
gh --version
```
⚠️ There is currently a bug with Codespaces that expects Git-LFS to be installed. Run the following command to remove the affected Git hooks.
```
rm .git/hooks/post-checkout
rm .git/hooks/post-commit
rm .git/hooks/post-merge
rm .git/hooks/pre-push
```
With our new configuration verified, let's commit the changes. Use VS Code's source control tools or the below terminal command.
```
git add '.devcontainer/devcontainer.json'
git commit -m 'feat: Add codespace configuration'
git push
```
With our dev container configuration committed, Mona will begin checking your work. Give her a moment to provide feedback and the next learning steps.

Step 2 - Passed ✅

Status	Description
✅ - Pass	Devcontainer image set to base:debian

🎉🎉🎉 Nice work! Everything is perfect! 🎉🎉🎉
Preparing content for step 3! One moment... 🤓

Step 3: Add Features

You can further customize your codespace by adding container feature, VS Code extensions, VS Code settings, host requirements, and much more.

Let's add the GitHub CLI, extensions to run the python program using VS Code, and a custom script to install some packages when first creating the Codespace.

⌨️ Activity: Add support for the Python

In VS Code, open the Command Palette (CTRL+SHIFT+P) and select the below command.
```
Codespaces: Add Dev Container Configuration Files...
```
Select the option Modify your active configuration....
In the list of features, search for and select Python from devcontainers.
- Instead of the defaults, pick Configure Options.
- Leave Install Tools set to true.
- Select Python version: 3.10
Navigate to and open the .devcontainer/devcontainer.json file.

Verify a new entry similar to the below was added.

"features": {
   "ghcr.io/devcontainers/features/python:1": {
      "installTools": true,
      "version": "3.10"
   }
},

⌨️ Activity: Add VS Code extensions

In the left navigation, select the Extension tab.
Search for python and find entries for Python and Python Debugger.
Right click on each entry and select the Add to devcontainer.json option.
Navigate to and open the .devcontainer/devcontainer.json file.

Verify a new entry similar to the below was added.

"customizations": {
   "vscode": {
      "extensions": [
         "ms-python.python",
         "ms-python.debugpy"
      ]
   }
},

⌨️ Activity: Add a custom script

The Dev Container specification provides multiple locations to run lifecycle scripts to further customize your Codespace. Let's add the postCreateCommand which runs one time after initial build (or rebuild).

Use the VS Code file explorer to create a script file with the below name.
```
.devcontainer/postCreate.sh
```
Alternately, run the below terminal command to create it.
```
touch .devcontainer/postCreate.sh
```
Make the script executable by running the below terminal command.
```
chmod +x .devcontainer/postCreate.sh
```

Open the .devcontainer/postCreate.sh file and add the following code, which will install an animation of a steam locomotive.

#!/bin/bash

sudo apt-get update
sudo apt-get install sl
echo "export PATH=\$PATH:/usr/games" >> ~/.bashrc
echo "export PATH=\$PATH:/usr/games" >> ~/.zshrc

Navigate to and open the .devcontainer/devcontainer.json file.
Create the postCreateCommand entry at the same level (top level) as features, and customizations.
```
"postCreateCommand": ".devcontainer/postCreate.sh"
```

With our new configuration finished, let's commit the changes. Use VS Code's source control tools or the below terminal command.

git add '.devcontainer/devcontainer.json'
git add '.devcontainer/postCreate.sh'
git commit -m 'feat: Add features, extensions, and postCreate script'
git push

Open the VS Code Command Palette (CTRL+Shift+P) and run the Codespaces: Rebuild Container command. Select the Rebuild option. A full build is not necessary.
Wait a few minutes for the Codespace to rebuild and VS Code to reconnect.
With the customizations committed, Mona will begin checking your work. Give her a moment to provide feedback and the next learning steps.

Tip

You can also configure your account to install dotfiles, allowing you to combine personal configurations with the project's configuration.

⌨️ Activity: (optional) Verify our customizations

Now that you've rebuilt the codespace, let's verify the python extension, python version, and custom script were adjusted correctly in the Codespace.

Ensure you are in the Codespace.
In the left sidebar, click the extensions tab and verify that the Python extensions are installed and enabled.
In the left sidebar, select Run and Debug tab and then press the Start Debugging icon. VS Code will open the lower panel and show the run logs.
In the lower panel, switch to the TERMINAL tab.
Run the following command to show the installed version of Python. Notice the others are not installed.
```
node --version
dotnet --version
python --version
gh --version
```
Run the following command to show the steam locomotive animation.
```
sl
```

Step 3 - Passed ✅

Status	Description
✅ - Pass	Features added to devcontainer.json
✅ - Pass	Customizations added to devcontainer.json
✅ - Pass	Postcreate command added to devcontainer.json
✅ - Pass	Postcreate script created

🎉🎉🎉 Nice work! Everything is perfect! 🎉🎉🎉
Preparing content for step 4! One moment... 🤓

Step 4: Test out our Codespace

The final test of our Codespace is to put ourselves in the position of an onboarding developer. Let's close everything and start up a new Codespace from nothing.

⌨️ Activity: Delete the existing codespace

Close the window running your VS Code Codespace.
Navigate to your exercise repository.
Above the files list on the right, click the green <> Code button.
Select the Codespaces tab to show the list of created Codespaces.
Find the active entry, select the three dot menu ..., and select the Delete command.

Tip

You can manage all of your Codespaces across all projects at https://github.com/codespaces

⌨️ Activity: Start a codespace

Above the files list on the right, click the green <> Code button.
Select the Codespaces tab and click the plus sign + or Create codespace on main button.

Alternately you can select the three dot menu ... to choose a different machine type, location, or configuration.
Wait a few minutes for the Codespace to be created and VS Code to connect.
(optional) Test out some of the activities from the previous steps to see if they still work!
Add an issue comment to let Mona know you finished this activity, then give her a moment to share the final review.
```
Hey @professortocat, I've finished testing out my new Codespace.
I'm ready to review!
```
Nice work! You are all done! 🎉

Please, follow the steps above.
I'll watch your progress in the background to provide feedback. 🧐

@professortocat

Hey @professortocat, I've finished testing out my new Codespace.
I'm ready to review!

Review

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

You learned how to create a codespace and push code to your repository from the codespace.
You learned how to use custom images, features, extensions, and scripts in your codespace.
You learned how to test run it like an onboarding developer.

Additional learning and resources

Developing in a codespace. Learn how to delete a codespace, open an existing codespace, connect to a private network, forward ports, and much more.
Set up your repository. Learn how to set minimum machine specs for a codespace, add badges, set up a template repo, and much more.
Personalize and customize GitHub Codespaces. Learn how to use setting sync for your codespace, add dotfiles, set the default region, set the default editor, and much more.
Prebuild your codespace
Manage your codespace

What's next?

Take another GitHub Skill exercise.
Read the Get started with GitHub docs.
To find projects to contribute to, check out GitHub Explore.

@dvmpr

Congratulations @dvmpr! You finished the exercise! 🎉🎉🎉

We've updated the repository with a couple changes to highlight your success!

Return to the repository home page to see your progress!

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Exercise: Code with Codespaces #1

Code with Codespaces

Step 1: Start a codespace and push some code

What's the big deal about Codespaces?

⌨️ Activity: Start a codespace

⌨️ Activity: Run the application

⌨️ Activity: Push changes to your repository from the codespace

Step 1 - Passed ✅

Step 2: Use a custom image in your codespace

How to configure a Codespace?

⌨️ Activity: Customize the codespace

Step 2 - Passed ✅

Step 3: Add Features

⌨️ Activity: Add support for the Python

⌨️ Activity: Add VS Code extensions

⌨️ Activity: Add a custom script

⌨️ Activity: (optional) Verify our customizations

Step 3 - Passed ✅

Step 4: Test out our Codespace

⌨️ Activity: Delete the existing codespace

⌨️ Activity: Start a codespace

Review

Additional learning and resources

What's next?

Metadata

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Exercise: Code with Codespaces #1

Description

Code with Codespaces

Activity

github-actions commented on Aug 20, 2026

Step 1: Start a codespace and push some code

What's the big deal about Codespaces?

⌨️ Activity: Start a codespace

⌨️ Activity: Run the application

⌨️ Activity: Push changes to your repository from the codespace

github-actions commented on Aug 20, 2026

Step 1 - Passed ✅

github-actions commented on Aug 20, 2026

github-actions commented on Aug 20, 2026

Step 2: Use a custom image in your codespace

How to configure a Codespace?

⌨️ Activity: Customize the codespace

github-actions commented on Aug 20, 2026

Step 2 - Passed ✅

github-actions commented on Aug 20, 2026

github-actions commented on Aug 20, 2026

Step 3: Add Features

⌨️ Activity: Add support for the Python

⌨️ Activity: Add VS Code extensions

⌨️ Activity: Add a custom script

⌨️ Activity: (optional) Verify our customizations

github-actions commented on Aug 20, 2026

Step 3 - Passed ✅

github-actions commented on Aug 20, 2026

github-actions commented on Aug 20, 2026

Step 4: Test out our Codespace

⌨️ Activity: Delete the existing codespace

⌨️ Activity: Start a codespace

github-actions commented on Aug 20, 2026

dvmpr commented on Aug 20, 2026

github-actions commented on Aug 20, 2026

Review

Additional learning and resources

What's next?

github-actions commented on Aug 20, 2026

Metadata

Metadata

Assignees

Labels

Projects

Milestone

Relationships

Development

Issue actions