Rename "roles" to "units". Put units in their own folders.

lib/units/device/plugins/sd.js

@@ -0,0 +1,33 @@
+var syrup = require('syrup')
+
+var logger = require('../../../util/logger')
+var wire = require('../../../wire')
+var wireutil = require('../../../wire/util')
+
+module.exports = syrup.serial()
+  .dependency(require('./service'))
+  .dependency(require('../support/router'))
+  .dependency(require('../support/push'))
+  .define(function(options, service, router, push) {
+    var log = logger.createLogger('device:plugins:sd')
+
+    router.on(wire.SdStatusMessage, function(channel, message) {
+      var reply = wireutil.reply(options.serial)
+      log.info('Getting SD card status')
+      service.getSdStatus(message)
+        .timeout(30000)
+        .then(function(mounted) {
+          push.send([
+            channel
+          , reply.okay(mounted ? 'sd_mounted' : 'sd_unmounted')
+          ])
+        })
+        .catch(function(err) {
+          log.error('Getting SD card Status', err.stack)
+          push.send([
+            channel
+          , reply.fail(err.message)
+          ])
+        })
+    })
+  })