LXD as developer isolation

I’m a developer. Loving it. What I hate is all the cruft my machine accumulates over the passing months. Have you ever tried NodeJS? Prepare for megabytes of javascript sprinkled over your system. Android development (or Java in general) is even worse.

Sure there are way of mitigating this problem somewhat. For Ruby you have rvm (or rbenv or …), for Python there’s virtual_env and for Node there’s nvm. In my humble opinion these solutions are nothing more than dirty shell hacks. God forbid if anything ever goes wrong. Or if you have to compile native binaries. This all ends in tears.

Long since I’ve been working my way to developer nirvana. I’ve created Ansible scripts to provision throwaway VPS’s, I’ve explored the wonderous realm of Chromebook development (there’s nothing to screw up!). AndI have really tried to love Docker. The promise is significant. Just spin up a new Docker image and your problems go away!

First of Docker is for production environments where all the experimentation has been done. Second the Dockerfile is terrible. Just some wonky DSL which really is just a shell script. Third starting several services is no fun. Sure there’s Compose but who whats all the complexity on you development machine.

LXD

Enter LXD. Which really is an easier LXC. Which really is an easier libvirt. Which really is an easier cgroups. Or so I think.

LXD let’s you start Linux containers right on your laptop. Shutting them down won’t delete all the changes you’ve done there. LXD is fast, networking recently became easy and sharing volumes never felt so relaxed. Copying files back and forth is easy too. I’ll let you read the docs instead of me explaining everything again here.

One confusing bit; there are two LXC’s. The first is the project you find on linuxcontainers.org and the other is the CLI client which ships with LXD. Forget about the first one. You start the *d*aemon lxd with which you interact with the CLI client lxc.

My setup

1. I have a prj directory with all my source ever which I share in each and every container I spin up.
2. I edit my code on my host machine and execute the code in the container.
3. If I mess up I delete the container.
4. Bliss

Wanna give Alpine Linux a try (you should)? Go for it. Really need that sweet Ubuntu packaged piece of kit? Spin up that container!

I’ve been using LXD for my experiments in machine learning (Tensorflow) and to follow the excellent Python video tutorials of sentdex. Crystal has it’s own container too. And all my clients nowadays are neatly seperated too! Good times.

Downsides

Obviously there are downsides. When doing stuff with hardware I had mediocre success. My Arduino works but adb can’t find my Android phone in the container (perhaps fixed in the latest release).

And I image anything non terminal is going to mess things up. IPython works great for me as this just runs on a port. But I doubt Android studio would work (but I don’t care since I edit my code on the host).

Hattip

Major props for the main developer of LXD Stéphane Graber. I feel he and his team have made the right design choices with regard to the interface and API, he’s also super helpful on his blog and on Twitter. Keep up the absolutely great work.