example-python-nix-env.nix

default.nix

let channels = rec {
  pkgs = import <nixpkgs> {};
  pkgs-unstable = import (fetchTarball https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz) {};
};
in with channels;

let dependencies = rec {
  _pip = pkgs.python36Packages.pip;
  _virtualenv = pkgs.python36Packages.virtualenv;
  _ipython = pkgs.python36Packages.ipython;
  _virtualenvwrapper = pkgs-unstable.python36Packages.virtualenvwrapper;

  _postgresql = pkgs.postgresql96.override { };
  _psycopg2 = pkgs.python36Packages.psycopg2;


  _flask = with pkgs.python36Packages; flask.override {
    name = "flask-0.12.2";
    src = pkgs.fetchurl {
      url = "https://files.pythonhosted.org/packages/eb/12/1c7bd06fcbd08ba544f25bf2c6612e305a70ea51ca0eda8007344ec3f123/Flask-0.12.2.tar.gz";
      sha256 = "49f44461237b69ecd901cc7ce66feea0319b9158743dd27a2899962ab214dac1";
    };
  };
  _flask_sqlalchemy = with pkgs.python36Packages; flask_sqlalchemy.override {
    name = "flask_SQLAlchemy-2.2";
    src = pkgs.fetchurl {
      url = "https://files.pythonhosted.org/packages/15/f0/0c90391352db8244321e22604d93cb6a4e3c538e9ab512b35ee5359b8d74/Flask-SQLAlchemy-2.2.tar.gz";
      sha256 = "f0d8241efba723d7b878f73550f5d3c0fbb042416123b52b36640b7491fa208b";
    };
  };
};
in with dependencies;

pkgs.stdenv.mkDerivation rec {
  name = "env";
  env = pkgs.buildEnv {
    name = name;
    paths = buildInputs;
  };

  builder = builtins.toFile "builder.pl" ''
    source $stdenv/setup; ln -s $env $out
  '';
  buildInputs = [
    (pkgs.python36.buildEnv.override {
      ignoreCollisions = true;
      extraLibs = [
        _pip
        _ipython

        _virtualenv
        _virtualenvwrapper

        _postgresql
        _psycopg2

        _flask
        _flask_sqlalchemy
      ];
    })
  ];
  shellHook = ''
    mkdir -p $PWD/postgresql
    mkdir -p $PWD/logs
    postgres -D `pwd`/postgresql >$PWD/logs/postgresql.log 2>&1 &
  '';
  }