Separate device functionality into plugins.

lib/roles/device/plugins/sub.js

@@ -0,0 +1,28 @@
+var syrup = require('syrup')
+
+var zmq = require('zmq')
+
+var logger = require('../../../util/logger')
+var wireutil = require('../../../wire/util')
+
+module.exports = syrup()
+  .dependency(require('./channels'))
+  .define(function(options, channels) {
+    var log = logger.createLogger('device:plugins:sub')
+
+    // Input
+    var sub = zmq.socket('sub')
+    options.endpoints.sub.forEach(function(endpoint) {
+      log.info('Receiving input from %s', endpoint)
+      sub.connect(endpoint)
+    })
+
+    // Establish always-on channels
+    ;[wireutil.global].forEach(function(channel) {
+      log.info('Subscribing to permanent channel "%s"', channel)
+      sub.subscribe(channel)
+      channels.register(channel, Infinity)
+    })
+
+    return sub
+  })