nixpkgs/doc/languages-frameworks/ruby.xml
Vladimír Čunát b405e82edb ruby docs: improve the example
- missing cd command
- invoke bundler through nix-shell, so it doesn't need to be on $PATH
  Note: running bundix through nix-shell won't work ATM, as the shell sets
  SSL_CERT_FILE=/no-cert-file.crt which prevents fetching throug https.
- use version from gemset to simplify updating
- don't break line in meta.description
2016-03-20 13:33:20 +01:00

80 lines
2.8 KiB
XML

<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-ruby">
<title>Ruby</title>
<para>There currently is support to bundle applications that are packaged as Ruby gems. The utility "bundix" allows you to write a <filename>Gemfile</filename>, let bundler create a <filename>Gemfile.lock</filename>, and then convert
this into a nix expression that contains all Gem dependencies automatically.</para>
<para>For example, to package sensu, we did:</para>
<screen>
<![CDATA[$ cd pkgs/servers/monitoring
$ mkdir sensu
$ cd sensu
$ cat > Gemfile
source 'https://rubygems.org'
gem 'sensu'
$ nix-shell -p bundler --command "bundler package --path /tmp/vendor/bundle"
$ $(nix-build '<nixpkgs>' -A bundix)/bin/bundix
$ cat > default.nix
{ lib, bundlerEnv, ruby }:
bundlerEnv rec {
name = "sensu-${version}";
version = (import gemset).sensu.version;
inherit ruby;
gemfile = ./Gemfile;
lockfile = ./Gemfile.lock;
gemset = ./gemset.nix;
meta = with lib; {
description = "A monitoring framework that aims to be simple, malleable, and scalable";
homepage = http://sensuapp.org/;
license = with licenses; mit;
maintainers = with maintainers; [ theuni ];
platforms = platforms.unix;
};
}]]>
</screen>
<para>Please check in the <filename>Gemfile</filename>, <filename>Gemfile.lock</filename> and the <filename>gemset.nix</filename> so future updates can be run easily.
</para>
<para>Resulting derivations also have two helpful items, <literal>env</literal> and <literal>wrapper</literal>. The first one allows one to quickly drop into
<command>nix-shell</command> with the specified environment present. E.g. <command>nix-shell -A sensu.env</command> would give you an environment with Ruby preset
so it has all the libraries necessary for <literal>sensu</literal> in its paths. The second one can be used to make derivations from custom Ruby scripts which have
<filename>Gemfile</filename>s with their dependencies specified. It is a derivation with <command>ruby</command> wrapped so it can find all the needed dependencies.
For example, to make a derivation <literal>my-script</literal> for a <filename>my-script.rb</filename> (which should be placed in <filename>bin</filename>) you should
run <command>bundix</command> as specified above and then use <literal>bundlerEnv</literal> lile this:</para>
<programlisting>
<![CDATA[let env = bundlerEnv {
name = "my-script-env";
inherit ruby;
gemfile = ./Gemfile;
lockfile = ./Gemfile.lock;
gemset = ./gemset.nix;
};
in stdenv.mkDerivation {
name = "my-script";
buildInputs = [ env.wrapper ];
script = ./my-script.rb;
buildCommand = ''
mkdir -p $out/bin
install -D -m755 $script $out/bin/my-script
patchShebangs $out/bin/my-script
'';
}]]>
</programlisting>
</section>