Monday, January 1, 2018

Low latency local CoCalc and SageMath on the Google Pixelbook: playing with Crouton, Gallium OS, Rkt, Docker

I just got CoCalc fully working locally on my Google Pixelbook Chromebook! I want this, since (1) I was inspired by a recent blog post about computer latency, and (2) I'm going to be traveling a lot next week (the JMM in San Diego -- come see me at the Sage booth), and may have times without Internet during which I want to work on CoCalc's development.

I first tried Termux, which is a "Linux in Android" userland that runs on the Pixelbook (via Android), but there were way, way too many problems for CoCalc, which is a very complicated application, so this was out. The only option was to enable ChromeOS dev mode.

I next considered partitioning the hard drive, installing Linux natively (in addition to ChromeOS), and dual booting. However, it seems the canonical option is Gallium OS and it nobody has got that to work with Pixelbook yet (?). In fact, it appears that Gallium OS development made have stopped a year ago (?). Bummer. So I gave up on that approach...

The next option was to try Crouton + Docker, since we have a CoCalc Docker image. Unfortunately, it seems currently impossible to use Docker with the standard ChromeOS kernel.  The next thing I considered was to use Crouton + Rkt, since there are blog posts claiming Rkt can run vanilla Docker containers on Crouton.

I setup Crouton, installed the cli-extra chroot, and easily installed Rkt. I learned how Rkt is different than Docker, and tried a bunch of simple standard Docker containers, which worked. However, when I tried running the (huge) CoCalc Docker container, I hit major performance issues, and things broke down. If I had the 16GB Chromebook and more patience, maybe this would have worked. But with only 8GB RAM, it really wasn't feasible.

The next idea was to just use Crouton Linux directly (so no containers), and fix whatever issues arose. I did this, and it worked well, with CoCalc giving me a very nice local browser-based interface to my Crouton environment. Also, since we've spent so much time optimizing CoCalc to be fast over the web, it feels REALLY fast when used locally. I made some changes to the CoCalc sources and added a directory, to hopefully make this easier if anybody else tries. This is definitely not a 1-click solution.

Finally, for SageMath I first tried the Ubuntu PPA, but realized it is hopelessly out of date. I then downloaded and extracted the Ubuntu 16.04 binary and it worked fine. Of course, I'm also building Sage from source (I'm the founder of SageMath after all), but that takes a long time...

Anyway, Crouton works really, really well on the Pixelbook, especially if you do not need to run Docker containers.