Refactor towards three-layer architecture

Create app container
Pass services down into lower layers (lower layers don't require singletons from src/services)

TODO:
- Move common utils (e.g., services/log) to `common`
- BalanceCache not used by default (i.e., caching is behind feature
  flag) and not a singleton.

package.json

@@ -39,7 +39,7 @@
     "koa": "^1.0.0",
     "koa-compress": "^1.0.6",
     "koa-mag": "^1.0.4",
-    "koa-passport": "^1.2.0",
+    "koa-passport": "^1.3.0",
     "koa-route": "^2.4.2",
     "koa-static": "^1.4.5",
     "lodash": "^3.5.0",

src/app.js

@@ -1,39 +1,102 @@
 'use strict'
 
+const _ = require('lodash')
+const co = require('co')
 const metadata = require('./controllers/metadata')
 const health = require('./controllers/health')
 const pairs = require('./controllers/pairs')
 const quote = require('./controllers/quote')
 const notifications = require('./controllers/notifications')
+const subscriptions = require('./models/subscriptions')
 const compress = require('koa-compress')
 const serve = require('koa-static')
 const route = require('koa-route')
 const errorHandler = require('five-bells-shared/middlewares/error-handler')
 const koa = require('koa')
 const path = require('path')
-const log = require('./services/log')
 const logger = require('koa-mag')
-const passport = require('koa-passport')
-const app = module.exports = koa()
+const Passport = require('koa-passport').KoaPassport
+const log = require('./services/log')
+
+function listen (koaApp, config, backend, ledgers) {
+  if (config.getIn(['server', 'secure'])) {
+    const spdy = require('spdy')
+    const tls = config.get('tls')
+
+    const options = {
+      port: config.getIn(['server', 'port']),
+      host: config.getIn(['server', 'bind_ip']),
+      key: tls.key,
+      cert: tls.cert,
+      ca: tls.ca,
+      crl: tls.crl,
+      requestCert: config.getIn(['auth', 'client_certificates_enabled']),
+
+      // Certificates are checked in the passport-client-cert middleware
+      // Authorization check is disabled here to allow clients to connect
+      // to some endpoints without presenting client certificates, or using a
+      // different authentication method (e.g., Basic Auth)
+      rejectUnauthorized: false
+    }
+
+    spdy.createServer(
+      options, koaApp.callback()).listen(config.getIn(['server', 'port']))
+  } else {
+    koaApp.listen(config.getIn(['server', 'port']))
+  }
+
+  log('app').info('connector listening on ' + config.getIn(['server', 'bind_ip']) + ':' +
+    config.getIn(['server', 'port']))
+  log('app').info('public at ' + config.getIn(['server', 'base_uri']))
+  for (let pair of config.get('tradingPairs')) {
+    log('app').info('pair', pair)
+  }
+
+  // Start a coroutine that connects to the backend and
+  // subscribes to all the ledgers in the background
+  co(function * () {
+    yield backend.connect()
+
+    yield subscriptions.subscribePairs(config.get('tradingPairs'), ledgers, config)
+  }).catch(function (err) {
+    log('app').error(typeof err === 'object' && err.stack || err)
+  })
+}
+
+function createApp (config, backend, ledgers) {
+  const koaApp = koa()
+
+  koaApp.context.config = config
+  koaApp.context.backend = backend
+  koaApp.context.ledgers = ledgers
+
+  // Configure passport
+  const passport = new Passport()
+  require('./services/auth')(passport, config)
+
+  // Logger
+  koaApp.use(logger())
+  koaApp.use(errorHandler({log: log('error-handler')}))
+  koaApp.use(passport.initialize())
 
-// Configure passport
-require('./services/auth')
+  koaApp.use(route.get('/', metadata.getResource))
+  koaApp.use(route.get('/health', health.getResource))
+  koaApp.use(route.get('/pairs', pairs.getCollection))
 
-// Logger
-app.use(logger())
-app.use(errorHandler({log: log('error-handler')}))
-app.use(passport.initialize())
+  koaApp.use(route.get('/quote', quote.get))
 
-app.use(route.get('/', metadata.getResource))
-app.use(route.get('/health', health.getResource))
-app.use(route.get('/pairs', pairs.getCollection))
+  koaApp.use(route.post('/notifications', notifications.post))
 
-app.use(route.get('/quote', quote.get))
+  // Serve static files
+  koaApp.use(serve(path.join(__dirname, 'public')))
 
-app.use(route.post('/notifications', notifications.post))
+  // Compress
+  koaApp.use(compress())
 
-// Serve static files
-app.use(serve(path.join(__dirname, 'public')))
+  return {
+    koaApp: koaApp,
+    listen: _.partial(listen, koaApp, config, backend, ledgers)
+  }
+}
 
-// Compress
-app.use(compress())
+module.exports = createApp

src/controllers/notifications.js

@@ -72,7 +72,7 @@ exports.post = function * postNotification () {
   const notification = yield requestUtil.validateBody(this, 'Notification')
   log.debug('Got notification: ' + JSON.stringify(notification))
   try {
-    yield model.processNotification(notification)
+    yield model.processNotification(notification, this.config, this.backend, this.ledgers)
   } catch (e) {
     if (!(e instanceof UnacceptableExpiryError)) {
       log.error('Notification handling received critical error: ' + e)

src/controllers/pairs.js

@@ -36,5 +36,5 @@ const model = require('../models/pairs')
  */
 /* eslint-enable */
 exports.getCollection = function * getCollection () {
-  this.body = model.getPairs()
+  this.body = model.getPairs(this.config)
 }

src/controllers/quote.js

@@ -109,6 +109,7 @@ const model = require('../models/quote')
 /* eslint-enable */
 
 exports.get = function * () {
-  this.body = yield model.getQuote(this.query)
+  this.body = yield model.getQuote(
+    this.query, this.ledgers, this.backend, this.config)
 }
 

src/index.js

@@ -1,65 +1,19 @@
 'use strict'
-const co = require('co')
 const ledgers = require('./services/ledgers')
 const config = require('./services/config')
-const log = require('./services/log')
 const backend = require('./services/backend')
-const subscriptions = require('./models/subscriptions')
-const app = require('./app')
-const ledgersService = require('./services/ledgers')
+const balanceCache = require('./services/balance-cache')
+const createApp = require('./app')
 
-function listen () {
-  if (config.getIn(['server', 'secure'])) {
-    const spdy = require('spdy')
-    const tls = config.get('tls')
-
-    const options = {
-      port: config.getIn(['server', 'port']),
-      host: config.getIn(['server', 'bind_ip']),
-      key: tls.key,
-      cert: tls.cert,
-      ca: tls.ca,
-      crl: tls.crl,
-      requestCert: config.getIn(['auth', 'client_certificates_enabled']),
-
-      // Certificates are checked in the passport-client-cert middleware
-      // Authorization check is disabled here to allow clients to connect
-      // to some endpoints without presenting client certificates, or using a
-      // different authentication method (e.g., Basic Auth)
-      rejectUnauthorized: false
-    }
-
-    spdy.createServer(
-      options, app.callback()).listen(config.getIn(['server', 'port']))
-  } else {
-    app.listen(config.getIn(['server', 'port']))
-  }
-
-  log('app').info('connector listening on ' + config.getIn(['server', 'bind_ip']) + ':' +
-    config.getIn(['server', 'port']))
-  log('app').info('public at ' + config.getIn(['server', 'base_uri']))
-  for (let pair of config.get('tradingPairs')) {
-    log('app').info('pair', pair)
-  }
-
-  // Start a coroutine that connects to the backend and
-  // subscribes to all the ledgers in the background
-  co(function * () {
-    yield backend.connect()
-
-    yield subscriptions.subscribePairs(config.get('tradingPairs'), ledgersService, config)
-  }).catch(function (err) {
-    log('app').error(typeof err === 'object' && err.stack || err)
-  })
-}
+const connector = createApp(config, backend, ledgers)
 
 module.exports = {
-  app: app,
-  listen: listen,
+  app: connector.koaApp,
+  listen: connector.listen,
   addLedger: ledgers.addLedger.bind(ledgers),
   _test: {
     BalanceCache: require('./lib/balance-cache'),
-    balanceCache: require('./services/balance-cache'),
+    balanceCache: balanceCache,
     loadConnectorConfig: require('./lib/config'),
     config: require('./services/config'),
     logger: require('./services/log'),
@@ -68,5 +22,5 @@ module.exports = {
 }
 
 if (!module.parent) {
-  listen()
+  connector.listen()
 }

src/models/notifications.js

@@ -2,9 +2,10 @@
 
 const payments = require('./payments')
 
-function * processNotification (notification) {
+function * processNotification (notification, config, backend, ledgers) {
   if (notification.event === 'transfer.update') {
-    yield payments.updateTransfer(notification.resource, notification.related_resources)
+    yield payments.updateTransfer(
+      notification.resource, notification.related_resources, config, backend, ledgers)
   }
 }
 

src/models/pairs.js

@@ -1,8 +1,6 @@
 'use strict'
 
-const config = require('../services/config')
-
-function getPairs () {
+function getPairs (config) {
   const tradingPairs = config.get('tradingPairs')
   return tradingPairs.map((pair) => {
     const currencies = pair.map(function (currencyLedgerString) {