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

lib/units/device/plugins/shell.js

@@ -0,0 +1,86 @@
+var Promise = require('bluebird')
+var syrup = require('syrup')
+
+var logger = require('../../../util/logger')
+var wire = require('../../../wire')
+var wireutil = require('../../../wire/util')
+
+module.exports = syrup.serial()
+  .dependency(require('../support/adb'))
+  .dependency(require('../support/router'))
+  .dependency(require('../support/push'))
+  .dependency(require('../support/sub'))
+  .define(function(options, adb, router, push, sub) {
+    var log = logger.createLogger('device:plugins:shell')
+
+    router.on(wire.ShellCommandMessage, function(channel, message) {
+      var reply = wireutil.reply(options.serial)
+
+      log.info('Running shell command "%s"', message.command)
+
+      adb.shell(options.serial, message.command)
+        .timeout(10000)
+        .then(function(stream) {
+          var resolver = Promise.defer()
+            , timer
+
+          function keepAliveListener(channel, message) {
+            clearTimeout(timer)
+            timer = setTimeout(forceStop, message.timeout)
+          }
+
+          function readableListener() {
+            var chunk
+            while ((chunk = stream.read())) {
+              push.send([
+                channel
+              , reply.progress(chunk)
+              ])
+            }
+          }
+
+          function endListener() {
+            push.send([
+              channel
+            , reply.okay(null)
+            ])
+            resolver.resolve()
+          }
+
+          function errorListener(err) {
+            resolver.reject(err)
+          }
+
+          function forceStop() {
+            stream.end()
+          }
+
+          stream.setEncoding('utf8')
+
+          stream.on('readable', readableListener)
+          stream.on('end', endListener)
+          stream.on('error', errorListener)
+
+          sub.subscribe(channel)
+          router.on(wire.ShellKeepAliveMessage, keepAliveListener)
+
+          timer = setTimeout(forceStop, message.timeout)
+
+          return resolver.promise.finally(function() {
+            stream.removeListener('readable', readableListener)
+            stream.removeListener('end', endListener)
+            stream.removeListener('error', errorListener)
+            sub.unsubscribe(channel)
+            router.removeListener(wire.ShellKeepAliveMessage, keepAliveListener)
+            clearTimeout(timer)
+          })
+        })
+        .error(function(err) {
+          log.error('Shell command "%s" failed', message.command, err.stack)
+          push.send([
+            channel
+          , reply.fail(err.message)
+          ])
+        })
+    })
+  })