https://github.com/lukateras/nix-of-mix

Sandboxable Mix (Elixir) project Nix evaluator
https://github.com/lukateras/nix-of-mix

elixir nix nix-of

Last synced: 26 days ago
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Sandboxable Mix (Elixir) project Nix evaluator

• Host: GitHub
• URL: https://github.com/lukateras/nix-of-mix
• Owner: lukateras
• License: cc0-1.0
• Created: 2019-08-05T07:32:57.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2024-12-20T03:58:37.000Z (about 2 months ago)
• Last Synced: 2025-01-08T05:47:09.590Z (28 days ago)
• Topics: elixir, nix, nix-of
• Language: Nix
• Homepage:
• Size: 53.7 KB
• Stars: 16
• Watchers: 2
• Forks: 3
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • License: COPYING

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README

        
## Overview

Nix function that reads `mix.lock` file and builds a Mix project.

Works inside the Nix sandbox.

To try it out, create the following `default.nix` in your Mix project:

```nix

with import  {};

let

  inherit (callPackage (fetchGit {

    url = https://gitlab.com/transumption/mix-to-nix;

    rev = "b70cb8f7fca80d0c5f7539dbfec497535e07d75c";

  }) {}) mixToNix;

in

mixToNix { src = ./.; }

```

Run `nix-build`.

### OTP apps

To start an OTP app, run:

```

$ cd result

$ MIX_ENV=prod \

  mix run -c /path/to/config.exs --no-deps-check --no-halt

```

### Escripts

To build an escript, override `postBuild` and `installPhase`:

```nix

(mixToNix { src = ./.; }).overrideAttrs (super: {

  postBuild = ''

    mix escript.build --no-deps-check

  '';

  installPhase = "install -Dt $out/bin ${super.pname}";

})

```

### Distillery

```nix

(mixToNix { src = ./.; }).overrideAttrs (super: {

  buildPhase = ''

    mix do deps.loadpaths --no-deps-check, release --env=prod

  '';

  

  installPhase = ''

    mkdir $out

    find _build -name \*.tar.gz | xargs cat | tar zxf - -C $out

  '';

})

```

## Details

If `src` is a path, it is filtered against `lib.cleanSource`, `_build/`, and

`deps/`.

[`elixir-to-json`](elixir-to-json) evaluates Elixir term in `mix.lock` and

marshals it to JSON. Tuples are represented as lists.

Then, Nix imports that JSON via `lib.importJSON`. Each `mix.lock` key

corresponds to a `deps/` path. Two types of deps are supported, `:git` and

`:hexpm`.

`:git` fetches given rev from `HEAD`. It doesn't support other branches just

yet, see [NixOS/nix#2409](https://github.com/NixOS/nix/pull/2409).

`:hexpm` fetches package from [Hex.pm](https://hex.pm). It comes with a SHA-256

hash of catenation of Mix archive version, package metadata, and `.tar.gz`

source code archive. Nix can only carry that catenation into the sandbox, so

[`binwalk`](https://github.com/ReFirmLabs/binwalk) finds where the source code

archive starts and extracts that part, ignoring archive version and metadata.

Mix, Rebar3 and ErlangMk deps are supported.

[`fake-hex-registry`](fake-hex-registry) creates a fake [Hex v1

registry](https://git.io/fhZuz) with dependencies for Rebar3 projects. [Rebar3

needs registry to function](https://github.com/erlang/rebar3/issues/1267).

Every dependency is built and cached individually via Nixpkgs `buildMix`

and `buildRebar3`.

## Quirks

`:git` dependencies are flat, so they are assumed to depend on every non-Git

entry in `mix.lock`. If this is undesirable, or if you want to make Git deps

depend on each other, you can override `beamDeps` via `overlay`.

If you have dependencies that require Rebar3 plugins (such as `pc` or

`rebar3_hex`), add them to `mix.exs` deps. These are normally unpinned and

non-sandboxable. You will also need to set `buildPlugins` via `overlay`. See

[`tests/02-fast-yaml`](tests/default.nix#L19) for example.