I find the saying “There’s more than one way to skin a cat”, just as much as the next guy, quite morbid and gruesome. And yet, I like to use it and tell myself that people aren’t really skinning cats for sport or professionally, it’s just a saying. So the cat we are going to skin today is Visual Studio Code.
I can’t believe I somehow, completely off-handedly and irresponsibly, added yet another opinion to the heated question of whether VS Code is an Editor or an IDE. I’m making a case it’s a cat, apparently.
We recently got hold of the hottest piece of hardware on the market these days.. The glorious A100 GPU. Granted, the H100 eclipsed it, and next year we will see the H200 and B100, however, for simple people like myself, the A100 is the best hardware I could realistically expect to work with. Now, we have it.
This beast of a hardware has been installed in a data center at an undisclosed location somewhere on earth, and attached to a Linux VM for us to use it through. As soon as we were given access, we immediately fired up our browsers, navigated to the JupyterLab service we previously prepared on this VM, and started mining crypto in the name of “Benchmarking the System”.
JK, of course, I would never admit to such illegal use of company hardware pfft.
OK, in all honesty, we simply logged in to JupyterLab, pulled some 7B, 13B, 30B, and 70B parameter LLMs, and let ‘em rip on the GPU.
We .. Were .. Blown .. Away.
The fact that high quality models, like the llama2 13B, loaded pretty quickly, and started giving us wealth of knowledge to use was incredible. My brain felt like fireworks were going off in it as I was thinking of all the possibilities. At the same time, I also realized that JupyterLab isn’t necessarily the ideal environment for maximum productivity. Users shared the same environment, it didn’t have powerful extensions like VS Code, and it was restricted in many ways.
It was time to dig some tunnels.
I started with Code Server, which is a project that aims to bring VS Code to the browser. It was a bit annoying to setup (running it on Docker, deploying it, connecting my stuff, security concerns, etc), but it worked well enough. My biggest pain point by far, though, was the lack of extensions. I had started using Github Copilot to write most of my code, as well as other Microsoft extensions for Python development, and none of them were available on Code Server.
Another serious issue I had was syncing my projects across devices. I always had to save my changes, push to git, pull from the other device, even though it was just me working on the project. Soon enough, I was able to get access to VS Code private beta of their remote development extension, aptly named “VSCode Server”.
VSCode Server was a retaliatory move by Microsoft to counter the success of Code Server (I speculate). It unlocked the full power of VS Code along with all the extensions we know and love. It was also much easier to setup, since it was just a VS Code extension. And yet, there was still a catch.
You see, when I switched to VSCode Server, I needed a safe way to connect from my iPad to whichever machine I was working on. Luckily, I stumbled upon NordVPN’s new feature at the time, Meshnet. It was an additional feature that made any device connected to NordVPN appear on the same network, as if they were all connected to the same router. :mind-blown:
If only it worked as reliably as it sounded.
Sadly, after the initial euphoria, I realized that the connection was unreliable, and I would often lose connection to the remote machine. After some time, I gave up on it, and came to terms with the fact that I would have to carry my laptop around with me.
Same Cat, Different Tunnel
Sorry for the unannounced segue regarding my previous attempts at remote development outside work, but I felt it was necessary to set the stage for the next part of this post.
So, let’s get back to the A100 GPU and our local development needs.
Since we were already running JupyterLab on the VM, the immediate solution that came to mind was to use JupyterLab’s VS Code extension to select a kernel running on the VM, and use that to run our code. This worked seamlessly, and honestly, I thought I as done then and there.
However, we quickly realized that code referencing broke. VS Code showed squiggly lines under all the imports, and we couldn’t navigate to the definitions of any of the functions we were using. This was a deal breaker for us.
Another side effect was the lack of structure parity between the local project and the actual environment. For example, if you want to import a local file, or use an LLM, you need to reference it from the remote server, which made it very awkward to work with.
Being a Good Host
At that point, I was like, no problem! We will just install Python 3 on the VM, and use that as an SSH host similar to how we were using WSL2 on Windows locally.
Since we are using RHEL 7, it had python 2.7 installed by default. So, I fired
up perplexity, and it gave me a perfect, step-by-step guide on how
to install Python 3 from source. I had to do it this way, since yum was
outdated, and I didn’t want to risk downloading potentially incompatible
packages from other sources. The installation went fine, until I started the
REPL, and it turned out I now needed to install/compile openssl, sqlite, and a
bunch of other stuff.
The Devil’s in the Container
Since we deploy all our services on Docker, it made sense to give Docker a shot at this. I wanted to try using Dev Containers for a while, but never had a good reason to do so. This was the perfect opportunity.
I struggled for a bit at first, since the default dev container settings I had was showing a warning as deprecated, while the new format didn’t yet have enough documentation and examples online. I eventually figured it out, but it was just for running a local container as a dev environment. I needed it on the GPU VM.
I first tested the obvious way, which is to connect to the host through VS Code SSH, then manage the dev containers. This kinda worked, but now you are in this inception-like situation where you are connecting to a VM through SSH, to run a container also on the remote host. Not a big fan.
I then researched on how to use the
DOCKER_HOST environment variable to
connect the local docker client to a remote docker daemon. This had the
potential to eliminate the need for the SSH step, however, it introduced a new
more serious problem. When VS Code tries to prepare the dev container, it
symlinks the local project to a folder, which is then mounted to the container
as a volume. We can’t symlink the local project to the VM, obviously.
The Final Boss
As the weekend came around, I was thinking about what to try next, since it seemed like such a simple problem! As I was thinking about the simple facts and the problem I’m trying to solve here, I realized that I could just have a remote container which the local VS Code can SSH into, just like WSL. I mean, just because we will be running the code in a container, doesn’t mean we have to use dev containers!
This is the step we are at right now, honestly. Just setting up a simple container that exposes an SSH server, and allows VS Code to connect to it directly, without the need to go through the host first. An initial PoC showed some promising results.
I’ve been reading Elon Musk’s biography, by Walter Isaacson, and I have to say, it’s been a very inspiring read. I shall impart a prat of the book I found particularly useful to apply at work:
- Question Every Requirement
- Delete as Much as Possible
- Simplify and Optimize