From 50a9db7a81544c6cba196c88b1f7561b4fd8f8db Mon Sep 17 00:00:00 2001
From: jschweik <jschweik@us.ibm.com>
Date: Tue, 12 Mar 2019 03:51:45 -0500
Subject: [PATCH] feat: add updateSentinels option to control new sentinel
 values being added to the original list (#814)

Closes #798.
---
 lib/connectors/SentinelConnector/index.ts |  6 +++
 lib/redis.js                              |  3 ++
 test/functional/sentinel.js               | 63 +++++++++++++++++++++++
 3 files changed, 72 insertions(+)

diff --git a/lib/connectors/SentinelConnector/index.ts b/lib/connectors/SentinelConnector/index.ts
index 07cbec1c..6f103cfa 100644
--- a/lib/connectors/SentinelConnector/index.ts
+++ b/lib/connectors/SentinelConnector/index.ts
@@ -30,6 +30,7 @@ interface ISentinelConnectionOptions extends ITcpConnectionOptions {
   connectTimeout?: number
   enableTLSForSentinelMode?: boolean
   sentinelTLS?: SecureContextOptions
+  updateSentinels?: boolean
 }
 
 export default class SentinelConnector extends AbstractConnector {
@@ -134,6 +135,11 @@ export default class SentinelConnector extends AbstractConnector {
   }
 
   private updateSentinels (client, callback: NodeCallback): void {
+
+    if (!this.options.updateSentinels) {
+      return callback(null)
+    }
+
     client.sentinel('sentinels', this.options.name, (err, result) => {
       if (err) {
         client.disconnect()
diff --git a/lib/redis.js b/lib/redis.js
index c6ea1d92..504ac7ab 100644
--- a/lib/redis.js
+++ b/lib/redis.js
@@ -88,6 +88,8 @@ 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 {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)
  * @extends Commander
  * @example
@@ -173,6 +175,7 @@ Redis.defaultOptions = {
     return Math.min(times * 10, 1000);
   },
   enableTLSForSentinelMode: false,
+  updateSentinels: true,
   // Status
   password: null,
   db: 0,
diff --git a/test/functional/sentinel.js b/test/functional/sentinel.js
index c7882861..75180a1a 100644
--- a/test/functional/sentinel.js
+++ b/test/functional/sentinel.js
@@ -124,6 +124,69 @@ describe('sentinel', function () {
         name: 'master'
       });
     });
+
+    it('should add additionally discovered sentinels when resolving successfully', function (done) {
+
+      var sentinels = [
+        { host: '127.0.0.1', port: 27379 }
+      ];
+
+      var sentinel = new MockServer(27379, function (argv) {
+        if (argv[0] === 'sentinel' && argv[1] === 'get-master-addr-by-name') {
+          return ['127.0.0.1', '17380'];
+        }
+        else if (argv[0] === 'sentinel' && argv[1] === 'sentinels') {
+          return [['ip', '127.0.0.1', 'port', '27379'], ['ip', '127.0.0.1', 'port', '27380']];
+        }
+
+      });
+      var master = new MockServer(17380);
+      sentinel.once('disconnect', function () {
+        redis.disconnect();
+        master.disconnect(function () {
+          expect(sentinels.length).to.eql(2);
+          sentinel.disconnect(done);
+        });
+      });
+
+      var redis = new Redis({
+        sentinels: sentinels,
+        name: 'master'
+      });
+    });
+
+    it('should skip additionally discovered sentinels even if they are resolved successfully', function (done) {
+
+      var sentinels = [
+        { host: '127.0.0.1', port: 27379 }
+      ];
+
+      var sentinel = new MockServer(27379, function (argv) {
+        if (argv[0] === 'sentinel' && argv[1] === 'get-master-addr-by-name') {
+          return ['127.0.0.1', '17380'];
+        }
+        else if (argv[0] === 'sentinel' && argv[1] === 'sentinels') {
+          return [['ip', '127.0.0.1', 'port', '27379'], ['ip', '127.0.0.1', 'port', '27380']];
+        }
+
+      });
+      var master = new MockServer(17380);
+      sentinel.once('disconnect', function () {
+        redis.disconnect();
+        master.disconnect(function () {
+          expect(sentinels.length).to.eql(1);
+          expect(sentinels[0].port).to.eql(27379);
+          sentinel.disconnect(done);
+        });
+      });
+
+      var redis = new Redis({
+        sentinels: sentinels,
+        updateSentinels: false,
+        name: 'master'
+      });
+    });
+
   });
 
   describe('master', function () {