From e66636acb93b73af962a2ead16308c78f8bf5764 Mon Sep 17 00:00:00 2001
From: Sander van der Burg <svanderburg@gmail.com>
Date: Fri, 7 Jul 2017 22:51:59 +0200
Subject: [PATCH] Initial commit

---
 .gitignore                        |   1 +
 LICENSE                           |  19 ++++
 README.md                         |  40 +++++++++
 bin/composer2nix.php              | 132 ++++++++++++++++++++++++++++
 composer.json                     |  19 ++++
 src/Composer2Nix/Generator.php    | 140 ++++++++++++++++++++++++++++++
 src/Composer2Nix/composer-env.nix | 124 ++++++++++++++++++++++++++
 7 files changed, 475 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 LICENSE
 create mode 100644 README.md
 create mode 100755 bin/composer2nix.php
 create mode 100644 composer.json
 create mode 100644 src/Composer2Nix/Generator.php
 create mode 100644 src/Composer2Nix/composer-env.nix

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..48b8bf9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+vendor/
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..938e480
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,19 @@
+Copyright (c) 2017 Sander van der Burg <svanderburg@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..822aba8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,40 @@
+composer2nix
+============
+`composer2nix` is a tool that can be used to generate [Nix](http://nixos.org)
+expressions for PHP [composer](https://getcomposer.org) packages.
+
+Nix integration makes it possible to use the Nix package manager (as opposed to
+composer) to deploy PHP packages including all their required dependencies.
+
+In addition, generated Nix composer packages
+support convenient integration of PHP applications with NixOS services, such as
+NixOS' Apache HTTP service.
+
+Usage
+=====
+You need a project providing both a `composer.json` and a `composer.lock`
+configuration file.
+
+Running the following command generates Nix expressions from the composer
+configuration files:
+
+    $ composer2nix
+
+The above command produces three expressions: `php-packages.nix` containing the
+dependencies, `composer-env.nix` the build infrastructure and `default.nix` that
+can be used to compose the package from its dependencies.
+
+Running the following command-line instruction deploys the package with Nix
+including its dependencies:
+
+    $ nix-build
+
+Limitations
+===========
+Currently, the state of this tool is that it is just a proof on concept
+implementation. As a result, it is lacking many features and probably buggy.
+Most importantly, only the `zip` and `git` dependencies are supported.
+
+License
+=======
+The contents of this package is available under the [MIT license](http://opensource.org/licenses/MIT)
diff --git a/bin/composer2nix.php b/bin/composer2nix.php
new file mode 100755
index 0000000..bc0d36e
--- /dev/null
+++ b/bin/composer2nix.php
@@ -0,0 +1,132 @@
+#!/usr/bin/env php
+<?php
+require_once(dirname(__FILE__)."/../vendor/autoload.php");
+
+use Composer2Nix\Generator;
+
+function displayHelp($command)
+{
+	print("Usage: ".$command." [OPTION]\n\n");
+	echo <<<EOT
+This executable can be used to generate Nix expressions from a composer.lock
+(and a composer.json) file so that a package and all its dependencies can be
+deployed by the Nix package manager.
+
+Options:
+     --config-file=FILE  Path to the composer.json file (defaults to:
+                         composer.json)
+     --lock-file=FILE    Path to the composer.lock file (defaults to:
+                         composer.lock)
+     --output=FILE       Path to the Nix expression containing the generated
+                         packages (defaults to: php-packages.nix)
+     --composition=FILE  Path to the Nix expression that composes the package
+                         (defaults to: default.nix)
+     --composer-env=FILE Path to the Nix expression deploying the composer
+                         packages (defaults to: composer-env.nix)
+     --prefer-source     Forces installation from package sources when possible
+     --prefer-dist       Forces installation from package dist
+     --name              Name of the generated package (defaults to the name
+                         provided in the composer.json file)
+     --no-copy-composer-env
+                         Do not create a copy of the Nix expression that builds
+                         composer packages
+ -h, --help              Shows the usage of this command
+ -v, --version           Shows the version of this command
+
+EOT;
+}
+
+function displayVersion($command)
+{
+	print($command." (composer2nix 0.0.1)\n\nCopyright (C) 2017 Sander van der Burg\n");
+}
+
+/* Parse command line options */
+
+$options = getopt("hv", array(
+	"config-file:",
+	"lock-file:",
+	"output:",
+	"composition:",
+	"composer-env:",
+	"prefer-source",
+	"prefer-dist",
+	"name:",
+	"no-copy-composer-env",
+	"help",
+	"version"
+));
+
+if($options === false)
+{
+	fwrite(STDERR, "Cannot parse the command-line options!\n");
+	exit(1);
+}
+
+/* Parse the options themselves */
+
+if(array_key_exists("h", $options) || array_key_exists("help", $options))
+{
+	displayHelp($argv[0]);
+	exit();
+}
+
+if(array_key_exists("v", $options) || array_key_exists("version", $options))
+{
+	displayVersion($argv[0]);
+	exit();
+}
+
+if(array_key_exists("config-file", $options))
+	$configFile = $options["config-file"];
+else
+	$configFile = "composer.json";
+
+if(array_key_exists("lock-file", $options))
+	$lockFile = $options["lock-file"];
+else
+	$lockFile = "composer.lock";
+
+
+if(array_key_exists("output", $options))
+	$outputFile = $options["output"];
+else
+	$outputFile = "php-packages.nix";
+
+if(array_key_exists("composition", $options))
+	$compositionFile = $options["composition"];
+else
+	$compositionFile = "default.nix";
+
+if(array_key_exists("composer-env", $options))
+	$composerEnvFile = $options["composer-env"];
+else
+	$composerEnvFile = "composer-env.nix";
+
+$noCopyComposerEnv = array_key_exists("no-copy-composer-env", $options);
+
+$installType = "dist"; // TODO: consult composer.json's preferred-install property. defaults to: auto
+
+if(array_key_exists("prefer-source", $options))
+	$installType = "source";
+
+if(array_key_exists("prefer-dist", $options))
+	$installType = "dist";
+
+if(array_key_exists("name", $options))
+	$name = $options["name"];
+else
+	$name = null;
+
+/* Execute the generator */
+
+try
+{
+	Generator::generateNixExpressions($name, $installType, $configFile, $lockFile, $outputFile, $compositionFile, $composerEnvFile, $noCopyComposerEnv);
+}
+catch(Exception $ex)
+{
+	fwrite(STDERR, $ex->getMessage()."\n");
+	exit(1);
+}
+?>
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..185ba53
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,19 @@
+{
+  "name": "svanderburg/composer2nix",
+  "description": "Generate Nix expressions to build PHP composer packages",
+  "type": "library",
+  "license": "MIT",
+  "authors": [
+    {
+      "name": "Sander van der Burg",
+      "email": "svanderburg@gmail.com",
+      "homepage": "http://sandervanderburg.nl"
+    }
+  ],
+  
+  "autoload": {
+    "psr-4": { "Composer2Nix\\": "src/Composer2Nix" }
+  },
+
+  "bin": [ "bin/composer2nix" ]
+}
diff --git a/src/Composer2Nix/Generator.php b/src/Composer2Nix/Generator.php
new file mode 100644
index 0000000..e6377d9
--- /dev/null
+++ b/src/Composer2Nix/Generator.php
@@ -0,0 +1,140 @@
+<?php
+namespace Composer2Nix;
+use Exception;
+
+class Generator
+{
+	function generateNixExpressions($name, $installType, $configFile, $lockFile, $outputFile, $compositionFile, $composerEnvFile, $noCopyComposerEnv)
+	{
+		/* Open the composer.json file and decode it */
+		$composerJSONStr = file_get_contents($configFile);
+
+		if($composerJSONStr === false)
+			throw new Exception("Cannot open contents of: ".$configFile);
+
+		$config = json_decode($composerJSONStr, true);
+
+		/* If no package name has been provided, attempt to use the name in the composer config file */
+		if($name === null)
+		{
+			if(array_key_exists("name", $config))
+				$name = $config["name"];
+			else
+			{
+				throw new Exception("Cannot determine a package name! Either add a name\n".
+					"property to the composer.json file or provide a --name parameter!");
+			}
+		}
+
+		$name = strtr($name, "/", "-"); // replace / by - since / is not allowed in Nix package names
+
+		/* Open the lock file and decode it */
+
+		if(file_exists($lockFile))
+		{
+			$composerLockStr = file_get_contents($lockFile);
+
+			if($composerLockStr === false)
+				throw new Exception("Cannot open contents of: ".$lockFile);
+
+			$lockConfig = json_decode($composerLockStr, true);
+		}
+		else
+			$lockConfig = null;
+
+		/* Generate packages expression */
+
+		$handle = fopen($outputFile, "w");
+
+		if($handle === false)
+			throw new Exception("Cannot write to: ".$outputFile);
+
+		if($lockConfig === null)
+			$packages = array();
+		else
+			$packages = $lockConfig["packages"];
+
+		fwrite($handle, "{composerEnv, fetchgit ? null}:\n\n");
+		fwrite($handle, "let\n");
+		fwrite($handle, "  dependencies = {\n");
+
+		foreach($packages as $package)
+		{
+			$sourceObj = $package[$installType];
+
+			switch($sourceObj["type"])
+			{
+				case "zip":
+					$hash = shell_exec('nix-prefetch-url "'.$sourceObj['url'].'"');
+					fwrite($handle, '    "'.$package["name"].'" = composerEnv.buildZipPackage {'."\n");
+					fwrite($handle, '      name = "'.strtr($package["name"], "/", "-").'-'.$sourceObj["reference"].'";'."\n");
+					fwrite($handle, '      url = "'.$sourceObj["url"].'";'."\n");
+					fwrite($handle, '      sha256 = "'.substr($hash, 0, -1).'";'."\n");
+					break;
+				case "git":
+					$outputStr = shell_exec('nix-prefetch-git "'.$sourceObj['url'].'" '.$sourceObj["reference"]);
+
+					$output = json_decode($outputStr, true);
+					$hash = $output["sha256"];
+
+					fwrite($handle, '    "'.$package["name"].'" = fetchgit {'."\n");
+					fwrite($handle, '      name = "'.strtr($package["name"], "/", "-").'-'.$sourceObj["reference"].'";'."\n");
+					fwrite($handle, '      url = "'.$sourceObj["url"].'";'."\n");
+					fwrite($handle, '      rev = "'.$sourceObj["reference"].'";'."\n");
+					fwrite($handle, '      sha256 = "'.$hash.'";'."\n");
+					break;
+				default:
+					throw new Exception("Cannot convert dependency of type: ".$sourceObj["type"]);
+			}
+
+			fwrite($handle, "    };\n");
+		}
+
+		fwrite($handle, "  };\n");
+		fwrite($handle, "in\n");
+		fwrite($handle, "composerEnv.buildPackage {\n");
+		fwrite($handle, '  name = "'.$name.'";'."\n");
+		fwrite($handle, "  src = ./.;\n");
+		fwrite($handle, "  inherit dependencies;\n");
+		fwrite($handle, "}\n");
+
+		fclose($handle);
+
+		/* Generate composition expression */
+
+		$handle = fopen($compositionFile, "w");
+
+		if($handle === false)
+			throw new Exception("Cannot write to: ".$compositionFile);
+
+		function composeNixFilePath($path)
+		{
+			if((strlen($path) > 0 && substr($path, 0, 1) === "/") || (strlen($path) > 1 && substr($path, 0, 2) === "./"))
+				return $path;
+			else
+				return "./".$path;
+		}
+
+		fwrite($handle, "{ pkgs ? import <nixpkgs> { inherit system; }\n");
+		fwrite($handle, ", system ? builtins.currentSystem\n");
+		fwrite($handle, "}:\n\n");
+
+		fwrite($handle, "let\n");
+		fwrite($handle, "  composerEnv = import ".composeNixFilePath($composerEnvFile)." {\n");
+		fwrite($handle, "    inherit (pkgs) stdenv writeTextFile fetchurl php unzip;\n");
+		fwrite($handle, "  };\n");
+		fwrite($handle, "in\n");
+		fwrite($handle, "import ".composeNixFilePath($outputFile)." {\n");
+		fwrite($handle, "  inherit composerEnv;\n");
+		fwrite($handle, "  inherit (pkgs) fetchgit;\n");
+		fwrite($handle, "}\n");
+
+		fclose($handle);
+
+		/* Copy composer-env.nix */
+
+		if(!$noCopyComposerEnv && !copy(dirname(__FILE__)."/composer-env.nix", $composerEnvFile))
+			throw new Exception("Cannot copy node-env.nix!");
+	}
+}
+?>
diff --git a/src/Composer2Nix/composer-env.nix b/src/Composer2Nix/composer-env.nix
new file mode 100644
index 0000000..fc6bda1
--- /dev/null
+++ b/src/Composer2Nix/composer-env.nix
@@ -0,0 +1,124 @@
+# This file originates from composer2nix
+
+{ stdenv, writeTextFile, fetchurl, php, unzip }:
+
+rec {
+  composer = stdenv.mkDerivation {
+    name = "composer-1.4.2";
+    src = fetchurl {
+      url = https://github.com/composer/composer/releases/download/1.4.2/composer.phar;
+      sha256 = "1x467ngxb976ba2r9kqba7jpvm95a0db8nwaa2z14zs7xv1la6bb";
+    };
+    buildInputs = [ php ];
+    
+    # We must wrap the composer.phar because of the impure shebang.
+    # We cannot use patchShebangs because the executable verifies its own integrity and will detect that somebody has tampered with it.
+    
+    buildCommand = ''
+      # Copy phar file
+      mkdir -p $out/share/php
+      cp $src $out/share/php/composer.phar
+      chmod 755 $out/share/php/composer.phar
+
+      # Create wrapper executable
+      mkdir -p $out/bin
+      cat > $out/bin/composer <<EOF
+      #! ${stdenv.shell} -e
+      exec ${php}/bin/php $out/share/php/composer.phar "\$@"
+      EOF
+      chmod +x $out/bin/composer
+    '';
+    meta = {
+      description = "Dependency Manager for PHP";
+      #license = stdenv.licenses.mit;
+      maintainers = [ stdenv.lib.maintainers.sander ];
+      platforms = stdenv.lib.platforms.unix;
+    };
+  };
+
+  buildZipPackage = { name, url, sha256 }:
+    stdenv.mkDerivation {
+      inherit name;
+      src = fetchurl {
+        inherit url sha256;
+      };
+      buildInputs = [ unzip ];
+      buildCommand = ''
+        unzip $src
+        baseDir=$(find . -type d -mindepth 1 -maxdepth 1)
+        cd $baseDir
+        mkdir -p $out
+        mv * $out
+      '';
+    };
+
+  buildPackage = { name, src, dependencies ? [], removeComposerArtifacts ? false }:
+    let
+      reconstructInstalled = writeTextFile {
+        name = "reconstructinstalled.php";
+        executable = true;
+        text = ''
+          #! ${php}/bin/php
+          <?php
+          $composerLockStr = file_get_contents($argv[1]);
+
+          if($composerLockStr === false)
+          {
+              print("Cannot open composer.lock contents");
+              exit(1);
+          }
+          else
+          {
+              $config = json_decode($composerLockStr);
+              $packagesStr = json_encode($config->packages, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
+              print($packagesStr);
+          }
+          ?>
+        '';
+      };
+    in
+    stdenv.mkDerivation {
+      inherit name src;
+      buildInputs = [ php composer ];
+      buildCommand = ''
+        cp -av $src $out
+        chmod -R u+w $out
+        cd $out
+
+        # Remove unwanted files
+        rm -f *.nix
+
+        export HOME=$TMPDIR
+
+        # Reconstruct the installed.json file from the lock file
+        mkdir -p vendor/composer
+        ${reconstructInstalled} composer.lock > vendor/composer/installed.json
+
+        # Symlink the provided dependencies
+        cd vendor
+        ${stdenv.lib.concatMapStrings (dependencyName:
+          let
+            dependency = dependencies.${dependencyName};
+          in
+          ''
+            vendorDir="$(dirname ${dependencyName})"
+            mkdir -p "$vendorDir"
+            ln -s "${dependency}" "$vendorDir/$(basename "${dependencyName}")"
+          '') (builtins.attrNames dependencies)}
+        cd ..
+
+        # Reconstruct autoload scripts
+        # We use the optimize feature because Nix packages cannot change after they have been built
+        # Using the dynamic loader for a Nix package is useless since there is nothing to dynamically reload.
+        composer dump-autoload --optimize
+
+        # Run the install step as a validation to confirm that everything works out as expected
+        composer install --optimize-autoloader
+
+        ${stdenv.lib.optionalString (removeComposerArtifacts) ''
+          # Remove composer stuff
+          rm composer.json composer.lock
+        ''}
+    '';
+  };
+}