nat support for sentinel connector

.gitignore

@@ -1,6 +1,7 @@
 node_modules
 *.cpuprofile
 /test.js
+/.idea
 built
 
 .vscode

lib/connectors/SentinelConnector/index.ts

@@ -1,4 +1,5 @@
 import {createConnection, Socket} from 'net'
+import {NatMap} from '../../cluster/ClusterOptions';
 import {CONNECTION_CLOSED_ERROR_MSG, packObject, sample} from '../../utils'
 import {connect as createTLSConnection, TLSSocket, SecureContextOptions} from 'tls'
 import {ITcpConnectionOptions, isIIpcConnectionOptions} from '../StandaloneConnector'
@@ -30,6 +31,7 @@ interface ISentinelConnectionOptions extends ITcpConnectionOptions {
   connectTimeout?: number
   enableTLSForSentinelMode?: boolean
   sentinelTLS?: SecureContextOptions
+  natMap: NatMap
   updateSentinels?: boolean
 }
 
@@ -152,7 +154,7 @@ export default class SentinelConnector extends AbstractConnector {
       result.map<IAddressFromResponse>(packObject as (value: any) => IAddressFromResponse).forEach(sentinel => {
         const flags = sentinel.flags ? sentinel.flags.split(',') : []
         if (flags.indexOf('disconnected') === -1 && sentinel.ip && sentinel.port) {
-          const endpoint = addressResponseToAddress(sentinel)
+          const endpoint = this.sentinelNatResolve(addressResponseToAddress(sentinel))
           if (this.sentinelIterator.add(endpoint)) {
             debug('adding sentinel %s:%s', endpoint.host, endpoint.port)
           }
@@ -174,7 +176,10 @@ export default class SentinelConnector extends AbstractConnector {
         if (err) {
           return callback(err)
         }
-        callback(null, Array.isArray(result) ? { host: result[0], port: Number(result[1]) } : null)
+
+        callback(null, this.sentinelNatResolve(
+          Array.isArray(result) ? { host: result[0], port: Number(result[1]) } : null
+        ))
       })
     })
   }
@@ -194,10 +199,19 @@ export default class SentinelConnector extends AbstractConnector {
         slave.flags && !slave.flags.match(/(disconnected|s_down|o_down)/)
       ))
 
-      callback(null, selectPreferredSentinel(availableSlaves, this.options.preferredSlaves))
+      callback(null, this.sentinelNatResolve(
+        selectPreferredSentinel(availableSlaves, this.options.preferredSlaves)
+      ))
     })
   }
 
+  sentinelNatResolve (item: ISentinelAddress) {
+    if (!item || !this.options.natMap)
+      return item;
+
+    return this.options.natMap[`${item.host}:${item.port}`] || item
+  }
+
   private resolve (endpoint, callback: NodeCallback<ITcpConnectionOptions>): void {
     if (typeof Redis === 'undefined') {
       Redis = require('../../redis')

lib/redis.js

@@ -88,6 +88,7 @@ var PromiseContainer = require('./promiseContainer');
  * strings. This option is necessary when dealing with big numbers (exceed the [-2^53, +2^53] range).
  * @param {boolean} [options.enableTLSForSentinelMode=false] - Whether to support the `tls` option
  * when connecting to Redis via sentinel mode.
+ * @param {NatMap} [options.natMap=null] NAT map for sentinel connector.
  * @param {boolean} [options.updateSentinels=true] - Update the given `sentinels` list with new IP
  * addresses when communicating with existing sentinels.
  * @extends [EventEmitter](http://nodejs.org/api/events.html#events_class_events_eventemitter)
@@ -174,6 +175,7 @@ Redis.defaultOptions = {
   sentinelRetryStrategy: function (times) {
     return Math.min(times * 10, 1000);
   },
+  natMap: null,
   enableTLSForSentinelMode: false,
   updateSentinels: true,
   // Status

test/functional/sentinel_nat.js

@@ -0,0 +1,72 @@
+describe('sentinel_nat', function() {
+  it('connects to server as expected', function(done) {
+
+    var sentinel = new MockServer(27379, function (argv) {
+      if (argv[0] === 'sentinel' && argv[1] === 'get-master-addr-by-name') {
+        return ['127.0.0.1', '17380'];
+      }
+    })
+
+    var redis = new Redis({
+      sentinels: [
+        { host: '127.0.0.1', port: '27379' }
+      ],
+      natMap: {
+        '127.0.0.1:17380': {
+          host: 'localhost',
+          port: 6379,
+        }
+      },
+      name: 'master',
+      lazyConnect: true,
+    })
+
+    redis.connect(function(err) {
+      if (err) {
+        sentinel.disconnect(function() {})
+        return done(err)
+      }
+      sentinel.disconnect(done)
+    })
+  })
+
+  it('rejects connection if host is not defined in map', function(done) {
+    var sentinel = new MockServer(27379, function (argv) {
+      if (argv[0] === 'sentinel' && argv[1] === 'get-master-addr-by-name') {
+        return ['127.0.0.1', '17380']
+      }
+
+      if (argv[0] === 'sentinel' && argv[1] === 'sentinels' &&argv[2] === 'master') {
+        return ['127.0.0.1', '27379']
+      }
+    })
+
+    var redis = new Redis({
+      sentinels: [
+        { host: '127.0.0.1', port: '27379' }
+      ],
+      natMap: {
+        '127.0.0.1:17381': {
+          host: 'localhost',
+          port: 6379,
+        }
+      },
+      maxRetriesPerRequest: 1,
+      name: 'master',
+      lazyConnect: true,
+    })
+
+    redis
+      .connect()
+      .then(function() {
+        throw new Error("Should not call")
+      })
+      .catch(function(err) {
+        if (err.message === 'Connection is closed.') {
+          return done(null)
+        }
+        sentinel.disconnect(done)
+      })
+  })
+
+})