fix(sdk): Load usbboot adapter on start

Change-type: patch
Changelog-entry: Load usbboot adapter on start on GNU/Linux if running as root.
Signed-off-by: Alexis Svinartchouk <alexis@resin.io>

lib/gui/app/modules/drive-scanner.js

@@ -18,7 +18,6 @@
 
 const settings = require('../models/settings')
 const SDK = require('../../../sdk')
-const permissions = require('../../../shared/permissions')
 
 const scanner = SDK.createScanner({
   blockdevice: {
@@ -29,17 +28,4 @@ const scanner = SDK.createScanner({
   usbboot: {}
 })
 
-// NOTE: Enable USBBoot on Linux if run as root
-permissions.isElevated().then((elevated) => {
-  if (elevated && process.platform === 'linux') {
-    const UsbbootAdapter = require('../../../sdk/adapters/usbboot')
-    const adapter = new UsbbootAdapter()
-    scanner.stop()
-    scanner.subscribe(adapter)
-    scanner.start()
-  }
-}).catch((error) => {
-  console.warn('Could not add usbboot adapter:', error)
-})
-
 module.exports = scanner

lib/sdk/adapters/index.js

@@ -19,6 +19,8 @@
 const _ = require('lodash')
 const os = require('os')
 
+const permissions = require('../../shared/permissions')
+
 /**
  * @summary The list of loaded adapters
  * @type {Object[]}
@@ -28,10 +30,8 @@ const ADAPTERS = [
   require('./blockdevice')
 ]
 
-// We don't support usbboot on GNU/Linux yet, given
+// On GNU/Linux, we only support usbboot when running as root.
-// that some distributions require root permissions
+if ((os.platform() !== 'linux') || permissions.isElevatedUnixSync()) {
-// to open USB devices.
-if (os.platform() !== 'linux') {
   ADAPTERS.push(require('./usbboot'))
 }
 

lib/shared/permissions.js

@@ -70,6 +70,26 @@ exports.isElevated = () => {
   return Bluebird.resolve(process.geteuid() === UNIX_SUPERUSER_USER_ID)
 }
 
+/**
+ * @summary Check if the current process is running with elevated permissions
+ * @function
+ * @public
+ *
+ * @description
+ *
+ * @returns {Boolean}
+ *
+ * @example
+ * permissions.isElevatedUnixSync()
+ *   if (isElevated) {
+ *     console.log('This process has elevated permissions');
+ *   }
+ * });
+ */
+exports.isElevatedUnixSync = () => {
+  return (process.geteuid() === UNIX_SUPERUSER_USER_ID)
+}
+
 /**
  * @summary Get environment command prefix
  * @function