WebVM

This repository hosts the source code for https://webvm.io, a Linux virtual machine that runs in your browser.

WebVM is a server-less virtual environment running fully client-side in HTML5/WebAssembly. It's designed to be Linux ABI-compatible. It runs an unmodified Debian distribution including many native development toolchains.

WebVM is powered by the CheerpX virtualization engine, and enables safe, sandboxed client-side execution of x86 binaries on any browser. CheerpX includes an x86-to-WebAssembly JIT compiler, a virtual block-based file system, and a Linux syscall emulator.

Enable networking

Modern browsers do not provide APIs to directly use TCP or UDP. WebVM provides networking support by integrating with Tailscale, a VPN network that supports WebSockets as a transport layer.

Open the "Networking" panel from the side-bar
Click "Connect to Tailscale" from the panel
Log in to Tailscale (create an account if you don't have one)
Click "Connect" when prompted by Tailscale
If you are unfamiliar with Tailscale or would like additional information see WebVM and Tailscale.

Fork, deploy, customize

Fork the repository.
Enable Github pages in settings.
- Click on Settings.
- Go to the Pages section.
- Select Github Actions as the source.
  - If you are using a custom domain, ensure Enforce HTTPS is enabled.
Run the workflow.
- Click on Actions.
- Accept the prompt. This is required only once to enable Actions for your fork.
- Click on the workflow named Deploy.
- Click Run workflow and then once more Run workflow in the menu.
After a few seconds a new Deploy workflow will start, click on it to see details.
After the workflow completes, which takes a few minutes, it will show the URL below the deploy_to_github_pages job.

You can now customize dockerfiles/debian_mini to suit your needs, or make a new Dockerfile from scratch. Use the Path to Dockerfile workflow parameter to select it.

Local deployment

From a local git clone

Download the debian_mini Ext2 image from https://github.com/leaningtech/webvm/releases/
- You can also build your own by selecting the "Upload GitHub release" workflow option
- Place the image in the repository root folder
Edit config_github_terminal.js
- Uncomment the default values for CMD, ARGS, ENV and CWD
- Replace IMAGE_URL with the URL (absolute or relative) for the Ext2 image. For example "/debian_mini_20230519_5022088024.ext2"
Build WebVM using npm, output will be placed in the build directory
- npm install
- npm run build
Start NGINX, it automatically points to the build directory just created
- nginx -p . -c nginx.conf
Visit http://127.0.0.1:8081 and enjoy your local WebVM

Example customization: Python3 REPL

The Deploy workflow takes into account the CMD specified in the Dockerfile. To build a REPL you can simply apply this patch and deploy.

diff --git a/dockerfiles/debian_mini b/dockerfiles/debian_mini
index 2878332..1f3103a 100644
--- a/dockerfiles/debian_mini
+++ b/dockerfiles/debian_mini
@@ -15,4 +15,4 @@ WORKDIR /home/user/
 # We set env, as this gets extracted by Webvm. This is optional.
 ENV HOME="/home/user" TERM="xterm" USER="user" SHELL="/bin/bash" EDITOR="vim" LANG="en_US.UTF-8" LC_ALL="C"
 RUN echo 'root:password' | chpasswd
-CMD [ "/bin/bash" ]
+CMD [ "/usr/bin/python3" ]

Bugs and Issues

Please use Issues to report any bug. Or come to say hello / share your feedback on Discord.

Thanks to...

This project depends on:

CheerpX, made by Leaning Technologies for x86 virtualization and Linux emulation
xterm.js, https://xtermjs.org/, for providing the Web-based terminal emulator
Tailscale, for the networking component
lwIP, for the TCP/IP stack, compiled for the Web via Cheerp

Versioning

WebVM depends on the CheerpX x86-to-WebAssembly virtualization technology, which is included in the project via NPM.

The NPM package is updated on every release.

Every build is immutable, if a specific version works well for you today, it will keep working forever.

License

WebVM is released under the Apache License, Version 2.0.

You are welcome to use, modify, and redistribute the contents of this repository.

The public CheerpX deployment is provided as-is and is free to use for technological exploration, testing and use by individuals. Any other use by organizations, including non-profit, academia and the public sector, requires a license. Downloading a CheerpX build for the purpose of hosting it elsewhere is not permitted without a commercial license.

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