theme	transition	paginate	style
gaia	swipe	true	section { font-size: 20px; } /* ⬇️ Mark the image of "1" in every pages as morphable image named as "one" ⬇️ / img[alt="1"] { view-transition-name: one; contain: layout; / required / } img[alt="2"] { view-transition-name: two; contain: layout; / required / } img[alt="3"] { view-transition-name: three; contain: layout; / required / } img[alt="4"] { view-transition-name: four; contain: layout; / required / } img[alt="5"] { view-transition-name: five; contain: layout; / required / } img[alt="6"] { view-transition-name: six; contain: layout; / required / } / Generic image styling for number icons */ img:is([alt="1"], [alt="2"], [alt="3"], [alt="4"], [alt="5"], [alt="6"]) { height: 64px; position: relative; top: -0.1em; vertical-align: middle; width: 64px; }

So, Someone is Annoying You About Nix

What am I going to cover?

Nix tutorials suck
Don't need the language first
Trust your gut
Don't python package by tomorrow
Understand stuff first

That's a little vague...

Maybe a check list would be cool...

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

What is Nix

Nix is Many Things!

Nix is...

What is Nix

Language

Hey kid, you wanna write Haskell and JSON?

{ lib
, buildNpmPackage
, fetchFromGitHub
}:

buildNpmPackage rec {
  pname = "reveal-md";
  version = "5.5.1";

  src = fetchFromGitHub {
    owner = "webpro";
    repo = "reveal-md";
    rev = version;
    hash = "sha256-BlUZsETMdOmnz+OFGQhQ9aLHxIIAZ12X1ipy3u59zxo=";
  };

  npmDepsHash = "sha256-xaDBB16egGi8zThHRrhcN8TVf6Nqkx8fkbxWqvJwJb4=";

  env = {
    PUPPETEER_SKIP_CHROMIUM_DOWNLOAD = true;
  };

  dontNpmBuild = true;

  doCheck = true;

  checkPhase = ''
    runHook preCheck

    npm run test

    runHook postCheck
  '';
}

What is Nix

Package Manager

Install exact packages

packages = with pkgs; [
    btop
    fd
    jq
    ijq
    pandoc
    sd
    silver-searcher
    skim
    tree
    unzip
    wget
    zip
];

What is Nix

Linux Distribution/Configuration of Same

Control all of your machine with nix!

  hardware.bluetooth = {
    enable = true;
    package = pkgs.bluez5-experimental;
    powerOnBoot = true;
    disabledPlugins = ["sap"];
    settings = {
      General = {
        JustWorksRepairing = "always";
        MultiProfile = "multiple";
      };
    };
  };

What is Nix

Dev Environments

Share your setup with the boys

pkgs.mkShell {
  packages = [ pkgs.gnumake ];

  inputsFrom = [ pkgs.hello pkgs.gnutar ];

  shellHook = ''
    export DEBUG=1
  '';

What is Nix

A ReadOnly File Store!

NO TOUCHY!

./
../
xrx4fpia9wp7mmfvriipi7j8qm85g4cm-helix-config.drv
xs2xmgd92ysv507645dik7fsfnhncpy2-unpack-zoneinfo_compiled-0.5.1.drv
xs5h45l67xc0v5n0hczch7d469nybzir-diff-so-fancy-1.4.4-fish-completions.drv
xs7g37asnv7r8rf89fn4a74syalqqsnk-clang-at-least-16-LLVMgold-path.patch.drv
xs9pkzjskplffcqh29h84fj09di173r0-tzdata-2024a.drv
xsa606vnc5ihnmbr08vdkz2sbd1g2xyh-source.drv
xsbsn3zdfhs29xw88q80yz9mp30ddsyl-tasty-1.4.3.tar.gz.drv
xsdpa50q8ikbqb5w9gwyadcr34wp6qs9-trove-classifiers-2023.8.7.tar.gz.drv
xsfg8jmzgkv2ijzw4saq1a7iaz6azxwy-serf-1.3.10.tar.bz2.drv
xsgbr42mw81sjkkqpxgvd7q985gg6cj6-apple-framework-QuartzCore-11.0.0.drv
xshfgc94k1f3i89wj51jjd2vr0lpbi1y-source.drv
xsiavfa0ybspkqmglm2xsyck4myipn61-CVE-2023-40305.part-2.patch.drv
xsis73vfcg4fswpjz59fmd8697xr2nh0-time-0.1.45.drv
xsm8zpiqgbfi2hip02ivq48da8kibldf-async-lock-3.3.0.drv
xsmg2h1ymqkhjhkxqvm6ly7qp5mpwmvm-setuptools-check-hook.drv
xsms9ajzmb4cfb9r4w2la195mag2s61w-clang-at-least-16-LLVMgold-path.patch.drv
xsnl56ldc390v1mr6lkvk5cd847dycbw-llvm-16.0.6.drv
xswcarhkw8pagcallh59y4dqkp214da4-jmespath-1.0.1.tar.gz.drv
xsxjcih2r3n1zgkmhkskddcscya6zcq8-go1.22.2.src.tar.gz.drv
xv2xnvf95d63h39z5ma9rc4761w6rwgn-apple-framework-SystemConfiguration-11.0.0.drv
xv3kymsqffw3gmxmsjmi5jfs182x8ivq-jsonschema_specifications-2023.7.1.tar.gz.drv
xv6dva0i78i0hygwib45g263nmdahlm5-python3.11-virtualenv-20.25.1.drv

What is Nix

A basic diagram

In case it made sense

    uses
┌────────────────────────────────────────────────┐
│                                                ∨
│  ┌─────────────────────────────────┐         ┌──────────────────┐                  ┌─────────────────────────────┐             ┌─────────────┐
│  │           Nix Darwin            │         │     Nixpkgs      │                  │                             │             │             │
│  │ configuration of Macos with nix │  uses   │     monorepo     │  is written in   │           NixLang           │  produces   │ Derivations │
│  │                                 │ ──────> │ helper functions │ ───────────────> │                             │ ──────────> │             │
│  └─────────────────────────────────┘         └──────────────────┘                  └─────────────────────────────┘             └─────────────┘
│                                                ∧                  uses
│                                                └─────────────────────────────────────┐
│                                                                                      │
│                                              ┌──────────────────┐                  ┌─────────────────────────────┐
│                                              │      NixOs       │  can configure   │        Home manager         │
└───────────────────────────────────────────── │                  │ ───────────────> │ Nix config of user programs │
                                               └──────────────────┘                  └─────────────────────────────┘

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

First Check Mark! Woo!
Woah! That's too many things!
Yup! Don't worry about any specifics right now
We're gonna start simple and fundamental.

Installing Nix

Install locally

Head to Deteminate Systems

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

But what's that curl-shell doing??

Use Cargo

cargo install nix-installer

Installing Nix

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

It Installs

Nix Daemon: Performs operations on the Nix Store for you.
Nix Store: A ReadOnly file system that stores what Nix builds
Nix Command: A set of command line applications that let run nix code and interact with the Nix Store

Installing Nix

Now you have Nix!

Veryify your install

run

$ nix shell nixpkgs#hello
$ hello
-> Hello, world!

You may have to start a new shell

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

Ok! Now you're in! What now?

Super Basics of Using Nix

Let's build this slide show!

Run:

nix run github:zdcthomas/nix-brown-bag#initial

Super Basics of Using Nix

Woah, That Was Easy!

I know!
That's the point!

Super Basics of Using Nix

But wait! There's more!

You can also use this repo's developer environment:

nix develop github:zdcthomas/nix-brown-bag

[ Note ]

The URL is the same, except for the package name at the end

Super Basics of Using Nix

How?

Just enter into a project that uses Nix and run nix develop if you want to use the developer shell they set up.

Use nix shell nixpkgs#<your package here> to temporarily install a package!

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

Another easy check! We're cruisin!

Yay!

Practically you can now make good use of Nix that other people wrote!

What is Nix, Really?

But what did I actually do?

Good question!

High level, you ran a package defined in the flake in this repo.

Let's build up to that answer though.

What is Nix, Really?

The Point of Nix

Nix aims to let us build the same software every time given the same inputs.

What do we mean by same?

What is Nix, Really?

Package == Package?

Nix assumes that two packages are the same if they have the same:

build steps
known build system
dependencies
"sealed" build environments

What is Nix, Really?

Derivation

Nix calls this combination of things a derivation

Special NixLang primitive
defines a blueprint for an actual artifact to be built

What is Nix, Really?

What is a derivation?

Open up the nix repl

nix repl nixpkgs

At their most basic, derivations look like

nix-repl> derivation {
    system = builtins.currentSystem;
    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";
    args = ["-c" "declare -xp;echo 'hello world!' > $out"];
    name = "test_package";
}

There's a lot to unpack here...

What is Nix, Really?

What is a derivation?

derivation {
    system = builtins.currentSystem;
    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";
    args = ["-c" "declare -xp;echo 'hello world!' > $out"];
    name = "test_package";
}

The system that a derivation gets built on in one of the things that defines a derivation

    system = builtins.currentSystem;

What is Nix, Really?

What is a derivation?

derivation {
    system = builtins.currentSystem;
    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";
    args = ["-c" "declare -xp;echo 'hello world!' > $out"];
    name = "test_package";
}

The builder is the base program used to build the program

    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";

This:

${legacyPackages.${builtins.currentSystem}.bash}/bin/bash

evaluates to a Nix Store Path:

/nix/store/60qp4q78hlg1fsvq4np6iv0gpqrl4v4p-bash-5.2p26/bin/bash

What is Nix, Really?

What is a derivation?

derivation {
    system = builtins.currentSystem;
    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";
    args = ["-c" "declare -xp;echo 'hello world!' > $out"];
    name = "test_package";
}

args are passed to the builder

    args = ["-c" "declare -xp;echo 'hello world!' > $out"];

But wait!! What's that $out?

What is Nix, Really?

What is a derivation?

derivation {
    system = builtins.currentSystem;
    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";
    args = ["-c" "declare -xp;echo 'hello world!' > $out"];
    name = "test_package";
}

$out is a environment variable passed to the builder that points at the output path designated for this derivation in the Nix Store

What is Nix, Really?

Building a derivation

Now we can actually build the derivation

nix-repl> d = derivation {
    system = builtins.currentSystem;
    builder = "${legacyPackages.${builtins.currentSystem}.bash}/bin/bash";
    args = ["-c" "declare -xp;echo 'hello world!' > $out"];
    name = "test_package";
}

nix-repl> :b d

This derivation produced the following outputs:
  out -> /nix/store/0z7i1bkp6p4zy29x82khkgbwch9wfgzi-test_derv

What is Nix, Really?

Building a derivation

We can see all Env Vars passed to the builder, including $out!

nix-repl> :log d
declare -x HOME="/homeless-shelter"
declare -x NIX_BUILD_CORES="0"
declare -x NIX_BUILD_TOP="/private/tmp/nix-build-test_derv.drv-0"
declare -x NIX_LOG_FD="2"
declare -x NIX_STORE="/nix/store"
declare -x OLDPWD
declare -x PATH="/path-not-set"
declare -x PWD="/private/tmp/nix-build-test_derv.drv-0"
declare -x SHLVL="1"
declare -x TEMP="/private/tmp/nix-build-test_derv.drv-0"
declare -x TEMPDIR="/private/tmp/nix-build-test_derv.drv-0"
declare -x TERM="xterm-256color"
declare -x TMP="/private/tmp/nix-build-test_derv.drv-0"
declare -x TMPDIR="/private/tmp/nix-build-test_derv.drv-0"
declare -x builder="/nix/store/60qp4q78hlg1fsvq4np6iv0gpqrl4v4p-bash-5.2p26/bin/bash"
declare -x name="test_derv"
declare -x out="/nix/store/0z7i1bkp6p4zy29x82khkgbwch9wfgzi-test_derv"
declare -x system="aarch64-darwin"

What is Nix, Really?

Building a derivation

And then the output in the Nix Store looks like this

nix-repl> builtins.readFile d
"hello world!\n"

What is Nix, Really?

What is a derivation?

In the Nix Store, a derivation path looks like:

0z7i1bkp6p4zy29x82khkgbwch9wfgzi-test_derv
▲                              ▲ ▲       ▲
└───────────────┬──────────────┘ └───┬───┘
                │                    │
           NAR Hash              PACKAGE NAME

Nar hash: A special type of hash of the derivations input
Package name: human readable name

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

Ok, again, way too much info

Yeah... sorry.

Ok, again, way too much

But now you have a firm basis so that actually using Nix doesn't feel like weird magic.

All the other Nix use-cases are programs that take outputs from derivations and symlinks them to somewhere else your system can use them

put nix store packages into your PATH
link them as configuration files
create systemd specifications
push a derivation or package to a cache

Let's get practical

Since derivations are so flexible, there's a truly wild number of ways nix is used.

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

Flakes!

Since derivations are so flexible, there's a truly wild number of ways nix is used.

Flakes!

Flakes are big functions with defined inputs and outputs.

Inputs

Can be

Other Flakes
Local Files/Directories
Repos
Artifacts from the internet

Flakes!

Flakes are big functions with defined inputs and outputs.

Outputs

Can Be

Packages
Apps
Ways to configure nixos machines
Developer shells
Flake templates
Checks for Ci/Tests

Flakes!

Basic Example

{
  description = "A very basic flake";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
  };

  outputs = { self, nixpkgs }: {

    packages.x86_64-linux.default = self.packages.x86_64-linux.hello;
    devShells.x86_64-linux.default = self.packages.x86_64-linux.mkShell {
        packages = [
            self.packages.x86_64-linux.hello
        ];
    };
  };
}

Flakes!

There's a few commands to interact with the output of Flakes:

nix build: build a derivation or fetch a store path
nix develop: run a bash shell that provides the build environment of a derivation
nix flake: manage Nix flakes
nix profile: manage Nix profiles
nix run: run a Nix application
nix search: search for packages
nix shell: run a shell in which the specified packages are available

Flakes!

Flakes are also used for system configuration

darwinConfigurations = let
    workHostName = "Zacharys-MacBook-Pro";
in {

    "${workHostName}" = let
    username = "zdcthomas";
    in
    darwin.lib.darwinSystem rec {
        system = "aarch64-darwin";
        specialArgs = {
        inherit system username overlays inputs workHostName;
        };
        modules = [
        {nixpkgs.overlays = overlays;}
        home-manager.darwinModule
        ./nix/hosts/work/dar_conf.nix
        ];
    };
};

Flakes!

You can install/configure programs and system settings

defaults = {
    NSGlobalDomain = {
        AppleShowAllFiles = true;
        NSAutomaticCapitalizationEnabled = false;
        NSAutomaticDashSubstitutionEnabled = false;
        NSAutomaticPeriodSubstitutionEnabled = false;
        NSAutomaticQuoteSubstitutionEnabled = false;
        NSAutomaticSpellingCorrectionEnabled = false;
        AppleKeyboardUIMode = 3;
    };
};

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang

Basics of NixLang

Attributes!

Nix is all about building Attribute Sets

{
    foo = "foo";
    bar = 1;
    baz = [1 2 3];
};

and passing them to derivations.

Basics of NixLang

Packaging

Nix has many wrappers around derivation.

MkDerivation

The most common wrapper; mkderivation introduces the concept of phases to the build, that let you specify actions to take at specific times in the creation of the derivation

stdenv.mkDerivation {
  name = "example-website-content";

  src = fetchFromGitHub {
    owner = "jekyll";
    repo = "example";
    rev = "5eb1b902ca3bda6f4b50d4cfcdc7bc0097bac4b7";
    sha256 = "1jw35hmgx2gsaj2ad5f9d9ks4yh601wsxwnb17pmb9j02hl3vgdm";
  };

  installPhase = ''
    export JEKYLL_ENV=production
    ${pkgs.jekyll}/bin/jekyll build --destination $out
  '';
  # ^ Phase here
}

Basics of NixLang

Convenience helpers

Writers

(
    writers.writeBashBin "dev_env"
    ''
    set -e

    AWS_PROFILE="kevel-studio-dev"
    export _EXTRA_PROMPT_STUFF="[DEV ENV]"

    ${aws} sso login --profile $AWS_PROFILE
    AWS_PROFILE=$AWS_PROFILE ${dev_env} --advertiser-api-db ${postgres_url}
    ''
)

Easy to use
take text (and maybe dependencies)
output runnable packages/data

Basics of NixLang

Convenience helpers

Language builders

The program that runs this slideshow is called slides.

It already exists in nixpkgs, but here we've built it from source for fun and learning

It uses a helper called buildGoModule (just mkDerivation with some go specific defaults)

Basics of NixLang

slides = pkgs.buildGoModule rec {
    pname = "slides";
    version = "0.9.0";

    src = pkgs.fetchFromGitHub {
        owner = "maaslalani";
        repo = "slides";
        rev = "f0996f65dd17e43ae49859360e5ca465e2609114";
        sha256 = "sha256-f7c9Gc7GN4xvz7W/Mu5Fq/XjKQ1nou7w8DIZUPv3Zds=";
    };

    nativeCheckInputs = with pkgs; [
        bash
        go
    ];

    vendorHash = "sha256-oV3UcbOC4y8xWnA5qZGEK/TRdQ4zCeZshgBAs2l+vSY=";

    ldflags = [
        "-s"
        "-w"
        "-X=main.Version=${version}"
    ];

    meta = with pkgs.lib; {
        description = "Terminal based presentation tool";
        homepage = "https://github.com/maaslalani/slides";
        changelog = "https://github.com/maaslalani/slides/releases/tag/v${version}";
        license = licenses.mit;
        maintainers = with maintainers; [maaslalani penguwin];
    };
};

Agenda

What Is Nix
Installing Nix
Super Basics of Using Nix
What is Nix, Really?
Flakes!
Basics of NixLang