Introduce SASS_BINARY_SITE environment variable

Provide ability to locally mirror node-sass
binaries for various versions and platforms.

SASS_BINARY_SITE needs to be an URL pointing to
a collection of files organized like the Github
repository.

If SASS_BINARY_SITE is set to

 http://myhost:8080/local/node-sass-bin/

then

 http://myhost:8080/local/node-sass-bin/v3.0.0-beta.5/freebsd-x64-14_binding.node

should point to the FreeBSD 64 bit binary for node 0.12.0

The URL can be also specified as the --sass-binary-site
commandline option or in the package.json:

 "nodeSassConfig": {
   "binarySite": <url>
 }

Remove --sass-binary-url and friends.

Also change priority and use package.json defaults
last, after command line arguments and the environment.

lib/extensions.js

@@ -50,7 +50,7 @@ function getRuntimeInfo() {
 /**
  * Get binary name.
  * If environment variable SASS_BINARY_NAME or
- * process aurgument --binary-name is provide,
+ * process argument --binary-name is provided,
  * return it as is, otherwise make default binary
  * name: {platform}-{arch}-{v8 version}.node
  *
@@ -62,10 +62,10 @@ function getBinaryName() {
 
   if (flags['--sass-binary-name']) {
     binaryName = flags['--sass-binary-name'];
-  } else if (package.nodeSassConfig && package.nodeSassConfig.binaryName) {
-    binaryName = package.nodeSassConfig.binaryName;
   } else if (process.env.SASS_BINARY_NAME) {
     binaryName = process.env.SASS_BINARY_NAME;
+  } else if (package.nodeSassConfig && package.nodeSassConfig.binaryName) {
+    binaryName = package.nodeSassConfig.binaryName;
   } else {
     binaryName = [process.platform, '-',
                   process.arch, '-',
@@ -76,21 +76,37 @@ function getBinaryName() {
 }
 
 /**
- * Retrieve the URL to fetch binary.
- * If environment variable SASS_BINARY_URL
- * is set, return that path. Otherwise make
- * path using current release version and
- * binary name.
+ * Determine the URL to fetch binary file from.
+ * By default feth from the node-sass distribution
+ * site on GitHub.
+ *
+ * The default URL can be overriden using
+ * the environment variable SASS_BINARY_SITE
+ * or a command line option --sass-binary-site:
+ *
+ *   node scripts/install.js --sass-binary-site http://example.com/
+ *
+ * The URL should to the mirror of the repository
+ * laid out as follows:
+ *
+ * SASS_BINARY_SITE/
+ *
+ *  v3.0.0-beta.4
+ *  v3.0.0-beta.4/freebsd-x64-14_binding.node
+ *  ....
+ *  v3.0.0-beta.5
+ *  v3.0.0-beta.5/freebsd-ia32-11_binding.node
+ *  v3.0.0-beta.5/freebsd-x64-42_binding.node
+ *  ... etc. for all supported versions and platforms
  *
  * @api private
  */
 
 function getBinaryUrl() {
-  return flags['--sass-binary-url'] ||
-         package.nodeSassConfig ? package.nodeSassConfig.binaryUrl : null ||
-         process.env.SASS_BINARY_URL ||
-         ['https://github.com/sass/node-sass/releases/download/v',
-          package.version, '/', sass.binaryName].join('');
+  var site = flags['--sass-binary-site'] ||
+             process.env.SASS_BINARY_SITE  ||
+             package.nodeSassConfig.binarySite;
+	return [site, 'v' + package.version, sass.binaryName].join('/');
 }
 
 /**
@@ -118,7 +134,7 @@ sass.versionInfo = getVersionInfo();
 /**
  * Get binary path.
  * If environment variable SASS_BINARY_PATH or
- * process aurgument --binary-path is provide,
+ * process argument --sass-binary-path is provided,
  * select it by appending binary name, otherwise
  * make default binary path using binary name.
  * Once the primary selection is made, check if
@@ -134,10 +150,10 @@ sass.getBinaryPath = function(throwIfNotExists) {
 
   if (flags['--sass-binary-path']) {
     binaryPath = flags['--sass-binary-path'];
-  } else if (package.nodeSassConfig && package.nodeSassConfig.binaryPath) {
-    binaryPath = package.nodeSassConfig.binaryPath;
   } else if (process.env.SASS_BINARY_PATH) {
     binaryPath = process.env.SASS_BINARY_PATH;
+  } else if (package.nodeSassConfig && package.nodeSassConfig.binaryPath) {
+    binaryPath = package.nodeSassConfig.binaryPath;
   } else {
     binaryPath = path.join(__dirname, '..', 'vendor', sass.binaryName.replace(/_/, '/'));
   }

package.json

@@ -18,6 +18,9 @@
     "node": ">=0.10.0"
   },
   "main": "lib/index.js",
+  "nodeSassConfig": {
+    "binarySite": "https://github.com/sass/node-sass/releases/download"
+  },
   "bin": {
     "node-sass": "bin/node-sass"
   },

scripts/install.js

@@ -20,22 +20,25 @@ require('../lib/extensions');
  */
 
 function download(url, dest, cb) {
-  applyProxy({ rejectUnauthorized: false }, function(options) {
-    var returnError = function(err) {
-      cb(typeof err.message === 'string' ? err.message : err);
-    };
-
-    request.get(url, options).on('response', function(response) {
-      if (response.statusCode < 200 || response.statusCode >= 300) {
-        returnError(['Can not download file from:', url].join());
-        return;
-      }
-
-      response.pipe(fs.createWriteStream(dest));
-
-      cb();
-    }).on('error', returnError);
-  });
+  var returnError = function(err) {
+	cb(typeof err.message === 'string' ? err.message : err);
+  };
+  if (url) {
+	applyProxy({ rejectUnauthorized: false }, function(options) {
+	  request.get(url, options).on('response', function(response) {
+		if (response.statusCode < 200 || response.statusCode >= 300) {
+		  returnError(['Can not download file from:', url].join());
+		  return;
+		}
+
+		response.pipe(fs.createWriteStream(dest));
+
+		cb();
+	  }).on('error', returnError);
+	});
+  } else {
+    returnError('Download URL not defined, set SASS_BINARY_SITE in the environment to enable download.');
+  }
 }
 
 /**