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A Very Short Introduction to Layering in Flox

Steve Swoyer | 2 Jul 2024

In games like Settlers of Catan, the Civilization series, or even Monopoly, a player's strengths or weaknesses are modified by the characteristics of the terrain they occupy, as well as the affordances of this terrain. Basically, their power and capabilities are determined by what's underneath them.

This is the easiest way to explain the concept of layering in Flox. When you layer Flox environments, the upper layers in the stack inherit the features and capabilities of the layers beneath them.

In other words, the layered Flox stack becomes at least as powerful as the sum of its constituent parts.

This means you can use Flox to create simple, use case-specific environments and layer them to form very powerful combinations. So what does this look like in practice—and why would you want to do this? Glad you asked! This blog demonstrates both the logic and the logistics of layering in Flox.

Stacking Environments

Let's start with a quick-and-dirty example of layering in practice. It's 9 AM. You've just finished your first octuple-shot macchiato of the day. Time to activate the Flox environments you need for today's work!

First, you activate default, the Flox environment that lives in your $HOME directory. This contains awscli2, git, jq, lastpass, your Rust toolchain, pokemonsay, and tons of other stuff. If your cwd is ~/dev/git/api-service, you'd type:

~ % flox activate -d ~/

Next, you activate your Node.js environment, node22, which includes basic stuff like ESLint, Prettier, and Mocha, along with tools like gcc, automake, the boost libraries, and other stuff you use to work with node-gyp, a cross-platform tool for building and compiling native add-ons for Node.js.

~ % flox activate -d ~/dev/floxenvs/node22

Finally, you activate your 1p environment, which includes the hooks you use to automate secrets management for your workflows in AWS, GitHub, and elsewhere.

~ % flox activate -d ~/dev/floxenvs/1p

In your terminal, this results in something like this:

~ % flox activate -d ~/
✅ You are now using the environment 'default'.
To stop using this environment, type 'exit'
 
flox [default] ~ %/ flox activate -d ~/dev/floxenvs/node22
✅ You are now using the environment 'node22'.
To stop using this environment, type 'exit'
 
flox [node22 default] ~ % flox activate -d ~/dev/floxenvs/1p
✅ You are now using the environment '1p'.
To stop using this environment, type 'exit'
 
flox [1p node22 default] ~ %

You're now within a Flox stack, flox [1p node22 default], comprising secrets management and Node.js + runtime dependencies layered on top of your default Flox environment. The binaries in this environment are unavailable when you're outside of it; inside of it, however, you can access and run them—along with any resources available to you as a user on your local system.

Try doing that in a container!

Layering 101: The Coworker from Hell

It's 9:01. Those Node.js v18 apps aren't going to refactor themselves.

But something's bugging you. A coworker who was fond of playing practical jokes recently left your org, and by sheer bad luck, you inherited some of their projects. Last night, whilst poking around in a couple of their repos, you stumbled across several dozen strange, possibly encrypted files.

They had unfamiliar extensions, like:

./malbouroboros/src/module8.mal
./malbouroboros/src/module7.mal
./malbouroboros/src/module1.mal
./malbouroboros/src/module14.mal

and:

./hassle/config/config19.hs
./hassle/config/config10.hs
./hassle/config/config14.hs
./hassle/config/config15.hs

You can't stop thinking about those repos—and those bizarre file extensions. What are they? What are they used for? Are they encrypted—or just pseudo-random nonsense?

You could do a Google search to find out, but you've got AIChat, a cool tool that lets you prompt LLMs from OpenAI, Anthropic, Ollama, and others via the command line. You can even use AIChat to pass LLMs files for analysis. You quickly run AIChat via the Flox remote environment you created and pushed to FloxHub:

flox [1p node22 default] flox activate -r daedalus/aichat

Remote environments are ephemeral: once you type exit, they disappear. They're great for ad hoc use cases, like this one. Presto! AIChat is up in less than a second in your terminal—it's now the top layer in your stack. You know you're in a remote environment because your Flox prompt tells you so:

flox [daedalus/aichat (remote) 1p node22 default] % aichat what is a .mal file type?
 
A .mal file type is commonly used as an abbreviation for the Malbolge
Programming language, a difficult-to-understand esoteric programming
language. Malbolge is known for being one of the most challenging
languages to learn and understand due to its complex and confusing design.

It tracks. It is absolutely on-brand for your former coworker, who always reminded you of The Office's Dwight Schrute. Okay. So you've got a mysterious repo of Malbolge code. What can you do with this?

flox [daedalus/aichat (remote) 1p node22 default] % aichat \
    can i port malbolge code to python or javascript?
 
Yes, it is possible to port Malbolge code to Python or JavaScript.
However, Malbolge is known as one of the most difficult programming
languages to understand and work with, so it may be challenging. You
will need a good understanding of both Malbolge and the target
language in order to successfully translate the code.

Curious, you decide to take a look at one of the files:

flox [daedalus/aichat (remote) 1p node22 default] % cat malbouroboros/config/01.mal
 
(=<`#9]~6ZY32VxwvutTSRqp+mlk\*ihg&edcbA98w76)4X2Vtsrqpomjilgfdcba\_^]ZYXWVTSRQPOMKJIHG?}
=<#9]7<)1s-xvtr-ponm+lkjih*g&fe(bY<6ZZZZZZZX4V2RQPO+MKJ*HGEDCB~A?=<:#9]~6ZY32VxwvutTSRqp+mlk\*ihg&edcbA98w76)4X2Vtsrqpomjilgfdcba\_^]ZYXWVTSRQPOMKJIHG?}
=<#9]7<)1s-xvtr-ponm+lkjih*g&fe(bY<6ZZZZZZZX4V2RQPO+MKJ*HGEDCB~A?=<:#9]~6ZY32VxwvutTSRqp+mlk\*ihg&edcbA98w76)4X2Vtsrqpomjilgfdcba\_^]ZYXWVTSRQPOMKJIHG?}
=<#9]7<)1s-xvtr-ponm+lkjih*g&fe(bY<6ZZZZZZZX4V2RQPO+MKJ*HGEDCB~A?=<:#9]~6ZY32VxwvutTSRqp+mlk\*ihg&edcbA98w76)4X2Vtsrqpomjilgfdcba\_^]ZYXWVTSRQPOMKJIHG?}
=<#9]7<)1s-xvtr-ponm+lkjih*g&fe(bY<6ZZZZZZZX4V2RQPO+MKJ*HGEDCB~A?=<:#9]~6ZY32VxwvutTSRqp+mlk\*ihg&edcbA98w76)4X2Vtsrqpomjilgfdcba\_^]ZYXWVTSRQPOMKJIHG?}

That looks ... terrifying. But maybe the Power of AI can help you make short work of this cryptic code?

flox [daedalus/aichat (remote) 1p node22 default] % cat ./malbouroboros/config/01.mal \
    | aichat can you tell me what this does
 
This code appears to be a series of encoded messages in a specific format.
It seems to consist of characters and symbols that do not follow a common
or recognizable pattern. Without more information about the encoding method
used, it is difficult to make sense of the code. Additional context or
decoding instructions would be needed to decipher the messages.

Yikes! Not gonna happen. But what about those .hs files? What's in that repo? More of the same?

flox [daedalus/aichat (remote) 1p node22 default] % aichat \
    what type of file lives in a repo called hassle and has the extension .hs?
 
A Haskell source code file would live in a repository called "hassle" and
have the extension ".hs". Haskell is a functional programming language
commonly used for writing source code files with the ".hs" extension.

That's more like it. You've actually heard of Haskell! Maybe you could do something with this repo?

flox [daedalus/aichat (remote) 1p node22 default] % aichat \
    is porting haskell code to python or javascript something i could do on my lunchbreak?
 
Porting Haskell code to Python or JavaScript on your lunch break can be quite
challenging due to the fundamental differences in these languages and may
require a significant amount of code restructuring and rewriting to achieve
the same functionality in the target languages. Overall, porting Haskell code
to Python or JavaScript would be a daunting task that would likely require
more time than you have available on your lunch break.

With that, you decide it's time to get to work. It's 9:15, and you've still got to figure out how to work around breaking changes in Node v22. That's a daunting enough task for you, thank you very much. But at least you've got a sense of where to start researching next.

Shaking your head, you type exit, killing your temporary Flox AIChat environment. Not only does this put you back in your layered Flox stack, but because you were using a Flox remote environment, there's no clean up: you don't have to uninstall any packages, or hunt down and delete orphaned libraries, config files, etc.

Wanna Take a Test Drive?

There's a lot more to layering in Flox, and we'll get down to the nitty gritty in a follow-up article.

SPOILER ALERT: We'll show how you can create a layered Flox stack that replicates a multi-container environment on your local system, with seamless access to all of your local resources. In a Flox stack, your environment variables are available and just work. You don't have to configure Flox to mount storage in your home directory or source code repo. You don't need to set environment variables and pass them into Flox, as with containers. And when you're "inside" a Flox environment, you're also "inside" your local system, so you won't ever be blocked because the tools you need aren't available.

And did we mention that it's super easy to containerize your Flox environments, should you need to?

Anyway, if you're at all intrigued by this walk-through, why not take Flox for a test drive?

You can download Flox for MacOS, as well as Red Hat- and Debian-flavored Linuxes.

Discover how Flox can transform your workflow in ways both subtle and stupendous.