Nix: construction reproductible

Bonjour Habrousers!

Aujourd'hui, nous allons continuer notre série d'articles sur Nix et comment nous l'utilisons chez Typeable.

Le premier article d'une série couvrant les bases du langage Nix peut être lu ici .

Haskell , , Haskell . , .

Github.

CI — . . Nix , . Nix , , .

, , . , Haskell, Hello world.

Main.hs



:

module Main where

main :: IO ()
main = putStrLn "Hello, World!"
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

Nix stack



( ). stack stack.yaml



, resolver



. — Hackage, Haskell, , (NB ): ).

stack.yaml



:

resolver: lts-17.11

packages:
- hello-world
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

hello-world.cabal



:

cabal-version:      2.4
name:               hello-world
version:            1.0
synopsis:           Hello World
license:            MIT
license-file:       LICENSE
author:             Nick

executable hello-world
    main-is:          Main.hs
    build-depends:    base >= 4 && < 5
    hs-source-dirs:   src
    default-language: Haskell2010
    ghc-options:      -Wall -O2
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

Nix , . , , :

$ stack run hello-world
Hello, World!
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

Come to the dar^Wnix side, we have cookies!

stack — Haskell, . Haskell Nix haskell.nix, IOHK. - . , , Nix.

Haskell.nix .cabal



- stack.yaml



derivation



Nix.

nix/stackyaml.nix



:

{
  #    haskell.nix  GitHub   Nixpkgs   .
  haskellNix ? import (builtins.fetchTarball "https://github.com/input-output-hk/haskell.nix/archive/b0d03596f974131ab64d718b98e16f0be052d852.tar.gz") {}
  #       Nixpkgs.  21.05   :)
, nixpkgsSrc ? haskellNix.sources.nixpkgs-2009
, nixpkgsArgs ? haskellNix.nixpkgsArgs
, pkgs ? import nixpkgsSrc nixpkgsArgs
}:

let
  #     stack.   Cabal   cabalProject.
  project = pkgs.haskell-nix.stackProject {
    name = "hello-world";

    # Derivation    .
    #  cleanGit      ,    git-.
    src = pkgs.haskell-nix.haskellLib.cleanGit {
      name = "hello-world";

      #  src     ,  stack.yaml.
      src = ../.;

      # keepGitDir   .git  .
      #    , ,      .
      keepGitDir = true;
    };

    #   modules         ,      .
    modules = [{
      # doCheck    -   ,       .
      #     ,       false     
      # .
      doCheck = false;

      #    Hello World  -Werror.
      packages.hello-world.components.exes.hello-world.ghcOptions = [ "-Werror" ];
    }];
  };

#       project --  ,   pkgs --  nixpkgs,     .
in { inherit project; inherit pkgs; }
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, Nix. nix build



. , result



, .

$ nix build project.hello-world.components.exes
$ ./result/bin/hello-world
Hello, World!
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

! , . !

Dockerfile? Dockerfile?

2021 , Docker . Typeable . nixpkgs



dockerTools



. , , . nix/docker.nix



.

, . Nix - , , , . , , . CentOS.

sourceImage = dockerTools.pullImage {
  imageName = "centos";
  imageDigest = "sha256:e4ca2ed0202e76be184e75fb26d14bf974193579039d5573fb2348664deef76e";
  sha256 = "1j6nplfs6999qmbhjkaxwjgdij7yf31y991sna7x4cxzf77k74v3";
  finalImageTag = "7";
  finalImageName = "centos";
};
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, - Docker. Nix, Docker Registry sourceImage



.

dockerTools buildImage



. , , :

makeDockerImage = name: revision: packages: entryPoint:
  dockerTools.buildImage {
    name = name;
    tag = revision;
    fromImage = sourceImage;
    contents = (with pkgs; [ bashInteractive coreutils htop strace vim ]) ++ packages;
    config.Cmd = entryPoint;
  };
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

makeDockerImage



: , ( Typeable git ), , , . CentOS (fromImage



), , .

, , .

hello-world = project.hello-world.components.exes.hello-world;
helloImage = makeDockerImage "hello" 
  (if imageTag == null then "undefined" else imageTag)
  [ hello-world ]
  [ "${hello-world}/bin/hello-world"
  ];
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, project.hello-world...



. , makeDockerImage



, hello-world



. imageTag



, , "undefined" .

:

$ nix build --argstr imageTag 1.0 helloImage
[4 built, 0.0 MiB DL]

 $ ls -l result
lrwxrwxrwx 1 user users 69 May 11 13:12 result -> /nix/store/56qqhiwahyi46g6mf355fjr1g6mcab0b-docker-image-hello.tar.gz
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

result



, . , .

$ docker load < result 
76241b8b0c76: Loading layer [==================================================>]  285.9MB/285.9MB
Loaded image: hello:1.0
$ docker run hello:1.0
Hello, World!
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, , Haskell. , haskell.nix - , : nixpkgs C/C++, Python, Node .

, Nix. Stay tuned!