nix + sandstorm = <3

README.md

The Generic steps to Sandstorm packaging shows a trivial nodejs server. We have a basic package.json to go a long with it.

But rather than using spk dev to find the relevant files, we write a a nix expression in default.nix including:

buildInputs = [ pkgs.nodejs ];

A Makefile ties the nix and sandstorm worlds together:

$ make
rm -rf result
nix-build
these derivations will be built:
  /nix/store/0ar2xxx4y4adkjysgn849r0yl52v2h74-spk1-0.1.drv
building path(s) ‘/nix/store/caskj1d5idk4zng9hhnmnw35j7hn285j-spk1-0.1’
patching script interpreter paths in /nix/store/caskj1d5idk4zng9hhnmnw35j7hn285j-spk1-0.1/bin/spk1
/nix/store/caskj1d5idk4zng9hhnmnw35j7hn285j-spk1-0.1/bin/spk1: interpreter directive changed from "/usr/bin/env node" to "/nix/store/g2b5wwyqz2khi7c36nmafvj1wdv9zykh-nodejs-4.4.6/bin/node"
/nix/store/caskj1d5idk4zng9hhnmnw35j7hn285j-spk1-0.1
find $(nix-store --query --requisites `readlink result`) | sed -e 's,^/,,' >sandstorm-files.list
spk pack spk1.spk
kxtqtg41d4smvxrahyss5221uhqahun1a4ukm03fep6prs6j9zr0

default.nix

{ pkgs ? import <nixpkgs> {} }:

pkgs.stdenv.mkDerivation rec {
  name = "spk1-0.1";
  src = ./.;
  script = ./index.js;

  buildInputs = [ pkgs.nodejs ];
  buildCommand = ''
    mkdir -p $out/bin/
    install -D -m755 $script $out/bin/spk1

    patchShebangs $out/bin/spk1
 '';
}

index.js

#!/usr/bin/env node

var http = require('http');
http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello World\n');
}).listen(11000, '127.0.0.1');
console.log('Server running at http://127.0.0.1:11000/');

Makefile

spk1.spk: sandstorm-pkgdef.capnp sandstorm-files.list
	spk pack $@

# Destination (in-package) path must not start with '/': /nix/store/6f...
sandstorm-files.list: result
#	nix-store --query --requisites result | sed -e 's,^/,,' >$@
	find $$(nix-store --query --requisites `readlink result`) | sed -e 's,^/,,' >$@

result: default.nix
	rm -rf result
	nix-build

clean:
	$(RM) -rf result sandstorm-files.list spk1 spk1.spk *~

package.json

{
  "name": "spk1",
  "version": "0.1.0",
  "description": "Sandstorm Package built with nix",
  "dependencies": {
  },
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "sandstorm",
    "capabilities"
  ],
  "author": "Dan Connolly",
  "license": "MIT"
}

sandstorm-pkgdef.capnp

@0xacf36ee19d3165aa;

using Spk = import "/sandstorm/package.capnp";
# This imports:
#   $SANDSTORM_HOME/latest/usr/include/sandstorm/package.capnp
# Check out that file to see the full, documented package definition format.

const pkgdef :Spk.PackageDefinition = (
  # The package definition. Note that the spk tool looks specifically for the
  # "pkgdef" constant.

  id = "kxtqtg41d4smvxrahyss5221uhqahun1a4ukm03fep6prs6j9zr0",
  # Your app ID is actually its public key. The private key was placed in
  # your keyring. All updates must be signed with the same key.

  manifest = (
    # This manifest is included in your app package to tell Sandstorm
    # about your app.

    appVersion = 0,  # Increment this for every release.
    appTitle = (defaultText = "Dan Sandstorm Pkg 1"),
    appMarketingVersion = (defaultText = "0.0.0"),

    actions = [
      # Define your "new document" handlers here.
      ( title = (defaultText = "Dan Sandstorm Pkg 1"),
        command = .myCommand
        # The command to run when starting for the first time. (".myCommand"
        # is just a constant defined at the bottom of the file.)
      )
    ],

    continueCommand = .myCommand
    # This is the command called to start your app back up after it has been
    # shut down for inactivity. Here we're using the same command as for
    # starting a new instance, but you could use different commands for each
    # case.
  ),

  sourceMap = (
    # Here we defined where to look for files to copy into your package. The
    # `spk dev` command actually figures out what files your app needs
    # automatically by running it on a FUSE filesystem. So, the mappings
    # here are only to tell it where to find files that the app wants.
    searchPath = [
      ( sourcePath = "result" ),  # Search this directory first.
      ( sourcePath = "/",    # Then search the system root directory.
        hidePaths = [ "home", "proc", "sys",
                      "etc/passwd", "etc/hosts", "etc/host.conf",
                      "etc/nsswitch.conf", "etc/resolv.conf" ]
        # You probably don't want the app pulling files from these places,
        # so we hide them. Note that /dev, /var, and /tmp are implicitly
        # hidden because Sandstorm itself provides them.
      )
    ]
  ),

  fileList = "sandstorm-files.list",
  # `spk dev` will write a list of all the files your app uses to this file.
  # You should review it later, before shipping your app.

  alwaysInclude = [
                "bin/spk1",
                "sandstorm-manifest",
                "sandstorm-http-bridge",
                "sandstorm-http-bridge-config"
                ]
  # Fill this list with more names of files or directories that should be
  # included in your package, even if not listed in sandstorm-files.list.
  # Use this to force-include stuff that you know you need but which may
  # not have been detected as a dependency during `spk dev`. If you list
  # a directory here, its entire contents will be included recursively.
);

const myCommand :Spk.Manifest.Command = (
  # Here we define the command used to start up your server.
  argv = ["/sandstorm-http-bridge", "11000", "--", "/bin/spk1"],
  environ = [
    # Note that this defines the *entire* environment seen by your app.
    (key = "PATH", value = "/usr/local/bin:/usr/bin:/bin"),
    (key = "HOME", value = "/var")
  ]
);