Secure Browser Access to code-server VSCode Behind Pomerium

In this guide, you'll run code-server's Visual Studio Code (VSCode) in a Docker container and secure browser access to your project with Pomerium, an open source reverse proxy.

What is code-server?

Code-server is an open-source tool that allows you to run VSCode, a popular integrated development environment (IDE), on a remote server through the browser. This setup essentially turns VSCode into a cloud-based IDE, providing flexibility and accessibility advantages.

Code-server is particularly popular among developers who want the full power of VSCode, but need to work in a cloud-based environment. This is ideal if you work on multiple machines, need to access your development environment remotely, or you have limited local resources.

How to secure code-server with Pomerium

Code-server requires password authentication by default. By securing code-server behind Pomerium, you can remove code-server’s password requirement and configure Pomerium to add authentication and authorization to an online instance of VSCode.

This guide shows you how to secure code-server with Pomerium. Here are the steps you’ll follow:

1. Install code-server and run it in a Docker container

2. Access your code-server project in the browser listening on localhost

3. Configure Pomerium to safely expose your code-server instance

By the end, you will have a minimal, real-world code-server instance that allows developer teams to write code using VSCode in the browser.

Before you start

If you completed Pomerium's Quickstart guide, you should have a working Pomerium project with the following YAML files:

• config.yaml
• docker-compose.yaml

If you haven't completed the Quickstart:

• Install Docker and Docker Compose
• Create a config.yaml file for your Pomerium configuration
• Create a docker-compose.yaml file for your Docker configuration

Set up Pomerium

In your config.yaml file, add the hosted authenticate service URL:

authenticate_service_url: https://authenticate.pomerium.app

Add the following route:

- from: https://code.localhost.pomerium.io
  to: http://codeserver:8080
  policy:
    - allow:
        or:
          - email:
              is: user@example.com
  allow_any_authenticated_user: true
  allow_websockets: true

Note: In this example route, code.localhost.pomerium.io is the publicly accessible route. codeserver is the local hostname for the server or container running code-server.

Set up Docker Compose

In your docker-compose.yaml file, add the code-server and Pomerium services:

version: '3'
services:
  pomerium:
    image: pomerium/pomerium:latest
    volumes:
      - ./config.yaml:/pomerium/config.yaml:ro
    ports:
      - 443:443
  codeserver:
    image: codercom/code-server:latest
    ports:
      - 8080:8080
    volumes:
      - ./code-server:/home/coder/project
      - ./code-server-config/.config:/home/coder/.config

Access code-server on localhost

Run docker compose up. In your browser, go to localhost:8080.

Code-server will prompt you to enter a password. You can find a pre-generated password in code-server-config/.config/code-server/config.yaml. If you enter it, you gain access to your code-server project.

However, remembering passwords is tedious. Let's disable the password requirement and use Pomerium to enforce authentication and authorization instead.

Access code-server behind Pomerium

In docker-compose.yaml, add the following command to your code-server container:

codeserver:
  image: codercom/code-server:latest
  ports:
    - 8080:8080
  volumes:
    - ./code-server:/home/coder/project
    - ./code-server-config/.config:/home/coder/.config
  command: --auth none --disable-telemetry /home/coder/project

This will disable the password prompt (and prevent code-server from collecting telemetry data from your project). Now, restart Docker Compose and access code-server using the route defined in config.yaml:

https://code.localhost.pomerium.io

After authenticating against the Cognito identity provider, you will be redirected to the code-server route.

Build a project in code-server

Now that you can access VSCode in your browser, test out code-server by building a quick HTML project.

1. Create an index.html file and add the following code:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Code-Server Sample</title>
  </head>
  <body>
    <h1 style="color:blueviolet">Check out more from Pomerium:</h1>
    <ul style="font-size: 20px;">
      <li><a href="https://www.pomerium.com/docs/guides">Guides</a></li>
      <li><a href="https://www.pomerium.com/blog/">Blog</a></li>
      <li><a href="https://www.pomerium.com/docs">Documentation</a></li>
    </ul>
    <h2 style="color:blueviolet">Happy coding!</h2>
  </body>
</html>

1. Go to Extensions and install Live Server
2. Right-click index.html and select Open with Live Server
3. Select any of the links to learn more about Pomerium

Great job! You successfully deployed code-server.

Note: When the code-server container is rebuilt, any files outside of /home/coder/project are reset, removing any dependencies (such as go and make). In a real remote development workflow, you could mount additional volumes, or use a custom code-server container with these dependencies installed.