Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. Share your development and build environments across different machines.
NixOS is a Linux distribution with a unique approach to package and configuration management. Built on top of the Nix package manager, it is completely declarative, makes upgrading systems reliable, and has many other advantages.
Download Get startedNix builds packages in isolation from each other. This ensures that they are reproducible and don't have undeclared dependencies, so if a package works on one machine, it will also work on another.
Nix makes it trivial to share development and build environments for your projects, regardless of what programming languages and tools you’re using.
Nix ensures that installing or upgrading one package cannot break other packages. It allows you to roll back to previous versions, and ensures that no package is in an inconsistent state during an upgrade.
The Nix Packages collection (nixpkgs) is a set of over 60 000 packages for the Nix package manager.
Don't clutter your system with tools that you use only now and then.
$ python --version python: command not found $ nix-shell -p python3 [nix-shell]$ python --version Python 3.7.7
$ nix-shell -p python3 nodejs go rustc [nix-shell]$ node --version v10.20.1 [nix-shell]$ go version go version go1.14.1 linux/amd64 [nix-shell]$ rustc --version rustc 1.42.0
After you get familiar with nix-shell -p you can take
the next step and learn some
Nix. To setup a more persistent environment you can also write a
simple shell.nix file:
{ pkgs ? import <nixpkgs> {}
}:
pkgs.mkShell {
name = "dev-shell";
buildInputs = [
pkgs.python3
pkgs.python3Packages.virtualenv
pkgs.nodejs
pkgs.yarn
];
}
Then enter development environment with:
$ nix-shell [nix-shell]$ virtualenv --version 16.7.9 [nix-shell]$ yarn --version 1.22.4
Commit the above shell.nix file and help your coworkers have
an easier time setting their development environment.
Using a Dockerfile, you are responsible for:
Writing a Dockerfile that would produce a minimal image is
at best a very error prone process.
With Nix, only packages you define are included in the Docker image. No cleaning up needed. There are no build tools left in your Docker image, keeping it as small as possible.
Nix also knows how to layer your resulting Docker image, automatically. The resulting layers are optimized for caching as much as possible.
The following Nix expression (default.nix) defines a
Docker image with only the hello package
in it.
{ pkgs ? import <nixpkgs> {}
}:
pkgs.dockerTools.buildLayeredImage {
name = "only-hello";
contents = [ pkgs.hello ];
}
To build and run the image you need to:
$ nix-build default.nix -o ./result ... /nix/store/…-docker-image-only-hello.tar.gz $ docker load -i ./result 1c31fbac2eb1: Loading layer [==================>] 1.649MB/1.649MB 03b22f688054: Loading layer [==================>] 256kB/256kB 29c350a9c392: Loading layer [==================>] 31.61MB/31.61MB 6a87e4d71e07: Loading layer [==================>] 266.2kB/266.2kB c09c43a6b910: Loading layer [==================>] 71.68kB/71.68kB Loaded image: only-hello:qn5x1pnk7d467jsl81jng7168qsks42l $ docker run only-hello:qn5x1pnk7d467jsl81jng7168qsks42l hello Hello, world
Learn more about how to build Docker images.
How hard would it be to build and configure an Amazon EC2 image?
With the following amazon.nix we configured nginx to
serve a "Welcome to nginx!" page, with a valid SSL certificate
(via LetsEncrypt) and recommended security settings.
{ pkgs, ...}:
{
security.acme.acceptTerms = true;
security.acme.email = "nix@example.com";
services.nginx = {
enable = true;
recommendedGzipSettings = true;
recommendedOptimisation = true;
recommendedProxySettings = true;
recommendedTlsSettings = true;
virtualHosts."example.com" = {
enableACME = true;
forceSSL = true;
locations."/".root = "${pkgs.nginx}/html";
};
};
}
Now we just need to build it.
$ nix-build '<nixpkgs/nixos/release.nix>' \ -A amazonImage.x86_64-linux \ --arg configuration ./amazon.nix \ -o ./result ... $ ls ./result/ nixos-amazon-image-20.09pre130979.gfedcba-x86_64-linux.vhd nix-support
The resulting Virtual Hard Disk image can be then be imported to Amazon EC2 as usual.