CodeBuddy

CodeBuddy is a learning management system that instructors can use to deliver computer-programming exercises. It was developed by the Piccolo Lab and has been used since 2019 in programming-oriented courses. It uses HTML/CSS/JavaScript on the client side and Python on the server side. It executes students' code securely within on the back end.

Here are some of CodeBuddy's features:

• Students' code is executed in Docker containers to provide isolation and make it easier to add new programming languages.
• Currently, CodeBuddy supports the following programming languages: bash, C, C++, Java, Javascript, Julia, Python, R, Rust. Send us a request if you would like to see another language supported.
• Instructors can require students to write code that generates either text or graphics. Currently, graphics are supported for Python (seaborn package) and R (ggplot2 package). CodeBuddy compares the student's output against the master solution and shows a diffed version.
• Instructors can configure exercises so that students can see the instructor's solution or anonymized solutions from peers.
• Instructors can configure exercises to support pair programming, an evidence-based teaching practice. When one student submits, the code (and score) show up under the other student's account as well.
• Timed assignments can be used. Instructors can use this feature for exams. During timed exams, instructors can restrict access so that other assignments in the course cannot be accessed.
• Instructors can create "hidden" tests. For example, they can ask students to write a function that accepts certain arguments but not tell them what the values will be. This prevents students from circumventing test requirements.
• Instructors can write "verification" code to statically analyze students' code before it is executed.
• Instructors can provide starter code and hints with exercise instructions.
• Instructors can upload data files that students must use when solving a problem.
• Instructors can deliver video-based content to students. For example, they can embed a YouTube video and require students to post a code- or text-based response to that content.
• When students are completing an assignment (exam) in a controlled environment that has no Internet access, instructors can configure the assignment to allow access to specific external URLs.
• Instructors can allow students to download all of their code from a course as a single HTML file.
• Teaching assistants can be added a course. They have access to solutions and students' scores but do not have the ability to change some course settings.
• Instructors can import and export assignments.

How to run a CodeBuddy instance

We have a live server running CodeBuddy here. If you would like to run your own instance, follow the instructions below.

Open a terminal

If you are using MacOS or Linux, you should already have a terminal. Go to the Applications menu, and open it. Then make sure you have installed the git command-line tool.

If you are using a Windows operating system, install git for windows. Then open Git Bash and use that as your terminal.

Install dependencies

CodeBuddy can be installed on any system that supports Docker and Python. Here are the steps to install it. You will need to have basic familiarity with executing commands through a terminal.

1. Install Docker Desktop. Make sure it is up and running.
2. Install Python (version 3.9+) and the pip package manager.
3. In the terminal, execute the following command to install the Python packages: pip install -r front_end/requirements.txt.
4. Modify Settings.yaml according to your preferences. The default settings should work in most cases.
5. Create a text file in front_end/secrets/front_end.yaml that contains a password that you wish to use for encrypting cookies, as well as Google authentication tokens. (Google authentication is not supported currently, so you can just use the placeholder values shown below for now.)

cookie: "abcdefg"
google_oauth_key: "123456789012-abc123a12aa12aaaa1aaaaa1aaaa1aa.apps.googleusercontent.com"
google_oauth_secret: "ABCDEFGHIJKLMNOP"

If you would like to contribute to developing CodeBuddy, complete these additional steps.

6. Install npm.
7. Install Make. (Try these instructions for Windows.)

Clone the repository

From a terminal window, use the cd command to change your working directory to where you wish to store the CodeBuddy code.

git clone <cloneURL>

Replace <cloneURL> with the GitHub clone address for this project (for example, https://github.com/srp33/CodeBuddy.git).

This will create a directory called CodeBuddy in your current working directory. Use the cd command to navigate to that directory.

Running the front end

For most users, the preferred option is to run the front end within Docker. To do this, execute the run_front_end script at the terminal. If you want to contribute to developing CodeBuddy, it might be helpful to run CodeBuddy outside of Docker so that you do not need to rebuild the Docker image each time you make a change. To do so, follow the steps described below.

1. Use the cd command to change your current working directory to front_end.
2. Build the HTML files. Execute the following command. make html
3. Build the static directory. Execute the following command. When it is done, hit Ctrl-C to move on. make build-watch
4. Start the development server. Execute the following command. make dev-server

When you modify files in the front_end/templates directory, you will need to re-run make html. When you change any of the Python code, you will need to hit Ctrl-C to stop the development server and then re-execute make dev-server.

Running the middle layer

Use the cd command to change your current working directory to middle_layer. Then execute the run_middle_layer script.