feat: support custom connectors (#906)

.eslintrc

@@ -1,6 +1,7 @@
 {
   "env": {
-    "node": true
+    "node": true,
+    "es6": true
   },
   "rules": {
     "no-const-assign": 2,

.travis.yml

@@ -12,6 +12,7 @@ services:
 - redis-server
 
 script:
+- npm run build
 - npm run test:cov || npm run test:cov || npm run test:cov
 
 env:

examples/basic_operations.js

@@ -27,6 +27,4 @@ redis.sadd('set', [1, 3, 5, 7]);
 redis.set('key', 100, 'EX', 10);
 
 // Change the server configuration
-redis.config('set', 'notify-keyspace-events', 'KEA')
-
-
+redis.config('set', 'notify-keyspace-events', 'KEA');

examples/custom_connector.js

@@ -0,0 +1,53 @@
+'use strict';
+
+const Redis = require('ioredis');
+const MyService = require('path/to/my/service');
+
+// Create a custom connector that fetches sentinels from an external call
+class AsyncSentinelConnector extends Redis.SentinelConnector {
+  constructor(options = {}) {
+    // Placeholder
+    options.sentinels = options.sentinels || [{ host: 'localhost', port: 6379 }];
+
+    // SentinelConnector saves options as its property
+    super(options);
+  }
+
+  connect(eventEmitter) {
+    return MyService.getSentinels().then(sentinels => {
+      this.options.sentinels = sentinels;
+      this.sentinelIterator = new Redis.SentinelIterator(sentinels);
+      return Redis.SentinelConnector.prototype.connect.call(this, eventEmitter);
+    });
+  }
+}
+
+const redis = new Redis({
+  connector: new AsyncSentinelConnector()
+});
+
+// ioredis supports all Redis commands:
+redis.set('foo', 'bar');
+redis.get('foo', function (err, result) {
+  if (err) {
+    console.error(err);
+  } else {
+    console.log(result);
+  }
+});
+redis.del('foo');
+
+// Or using a promise if the last argument isn't a function
+redis.get('foo').then(function (result) {
+  console.log(result);
+});
+
+// Arguments to commands are flattened, so the following are the same:
+redis.sadd('set', 1, 3, 5, 7);
+redis.sadd('set', [1, 3, 5, 7]);
+
+// All arguments are passed directly to the redis server:
+redis.set('key', 100, 'EX', 10);
+
+// Change the server configuration
+redis.config('set', 'notify-keyspace-events', 'KEA');

lib/connectors/AbstractConnector.ts

@@ -17,5 +17,5 @@ export default abstract class AbstractConnector {
     }
   }
 
-  public abstract connect (callback: Function, _: ErrorEmitter)
+  public abstract connect (_: ErrorEmitter): Promise<NetStream>
 }

lib/connectors/SentinelConnector/SentinelIterator.ts

@@ -5,23 +5,19 @@ function isSentinelEql (a: Partial<ISentinelAddress>, b: Partial<ISentinelAddres
     ((a.port || 26379) === (b.port || 26379))
 }
 
-export default class SentinelIterator {
+export default class SentinelIterator implements Iterator<Partial<ISentinelAddress>> {
   private cursor: number = 0
 
   constructor (private sentinels: Partial<ISentinelAddress>[]) {}
 
-  hasNext (): boolean {
-    return this.cursor < this.sentinels.length
-  }
-
-  next (): Partial<ISentinelAddress> | null {
-    return this.hasNext() ? this.sentinels[this.cursor++] : null
+  next () {
+    const done = this.cursor >= this.sentinels.length
+    return { done, value: done ? undefined : this.sentinels[this.cursor++] }
   }
 
   reset (moveCurrentEndpointToFirst: boolean): void {
     if (moveCurrentEndpointToFirst && this.sentinels.length > 1 && this.cursor !== 1) {
-      const remains = this.sentinels.slice(this.cursor - 1)
-      this.sentinels = remains.concat(this.sentinels.slice(0, this.cursor - 1))
+      this.sentinels.unshift(...this.sentinels.splice(this.cursor - 1))
     }
     this.cursor = 0
   }

lib/connectors/SentinelConnector/index.ts

@@ -6,7 +6,8 @@ import {ITcpConnectionOptions, isIIpcConnectionOptions} from '../StandaloneConne
 import SentinelIterator from './SentinelIterator'
 import {ISentinelAddress} from './types';
 import AbstractConnector, { ErrorEmitter } from '../AbstractConnector'
-import {NetStream} from '../../types'
+import {NetStream, CallbackFunction} from '../../types';
+import * as PromiseContainer from '../../promiseContainer';
 import Redis from '../../redis'
 
 const debug = Debug('SentinelConnector')
@@ -17,12 +18,13 @@ interface IAddressFromResponse {
   flags?: string
 }
 
-type NodeCallback<T = void> = (err: Error | null, result?: T) => void
 type PreferredSlaves =
   ((slaves: Array<IAddressFromResponse>) => IAddressFromResponse | null) |
   Array<{port: string, ip: string, prio?: number}> |
   {port: string, ip: string, prio?: number}
 
+export { ISentinelAddress, SentinelIterator };
+
 export interface ISentinelConnectionOptions extends ITcpConnectionOptions {
   role: 'master' | 'slave'
   name: string
@@ -39,12 +41,12 @@ export interface ISentinelConnectionOptions extends ITcpConnectionOptions {
 
 export default class SentinelConnector extends AbstractConnector {
   private retryAttempts: number
-  private sentinelIterator: SentinelIterator
+  protected sentinelIterator: SentinelIterator
 
   constructor (protected options: ISentinelConnectionOptions) {
     super()
 
-    if (this.options.sentinels.length === 0) {
+    if (!this.options.sentinels.length) {
       throw new Error('Requires at least one sentinel to connect to.')
     }
     if (!this.options.name) {
@@ -68,19 +70,20 @@ export default class SentinelConnector extends AbstractConnector {
     return roleMatches
   }
 
-  public connect (callback: NodeCallback<NetStream>, eventEmitter: ErrorEmitter): void {
+  public connect (eventEmitter: ErrorEmitter): Promise<NetStream> {
     this.connecting = true
     this.retryAttempts = 0
 
     let lastError
-    const _this = this
-    connectToNext()
-
-    function connectToNext() {
-      if (!_this.sentinelIterator.hasNext()) {
-        _this.sentinelIterator.reset(false)
-        const retryDelay = typeof _this.options.sentinelRetryStrategy === 'function'
-          ? _this.options.sentinelRetryStrategy(++_this.retryAttempts)
+    const _Promise = PromiseContainer.get();
+
+    const connectToNext = () => new _Promise<NetStream>((resolve, reject) => {
+      const endpoint = this.sentinelIterator.next();
+
+      if (endpoint.done) {
+        this.sentinelIterator.reset(false)
+        const retryDelay = typeof this.options.sentinelRetryStrategy === 'function'
+          ? this.options.sentinelRetryStrategy(++this.retryAttempts)
           : null
 
         let errorMsg = typeof retryDelay !== 'number'
@@ -95,32 +98,33 @@ export default class SentinelConnector extends AbstractConnector {
 
         const error = new Error(errorMsg)
         if (typeof retryDelay === 'number') {
-          setTimeout(connectToNext, retryDelay)
+          setTimeout(() => {
+            resolve(connectToNext());
+          }, retryDelay)
           eventEmitter('error', error)
         } else {
-          callback(error)
+          reject(error)
         }
         return
       }
 
-      const endpoint = _this.sentinelIterator.next()
-      _this.resolve(endpoint, function (err, resolved) {
-        if (!_this.connecting) {
-          callback(new Error(CONNECTION_CLOSED_ERROR_MSG))
+      this.resolve(endpoint.value, (err, resolved) => {
+        if (!this.connecting) {
+          reject(new Error(CONNECTION_CLOSED_ERROR_MSG))
           return
         }
         if (resolved) {
           debug('resolved: %s:%s', resolved.host, resolved.port)
-          if (_this.options.enableTLSForSentinelMode && _this.options.tls) {
-            Object.assign(resolved, _this.options.tls)
-            _this.stream = createTLSConnection(resolved)
+          if (this.options.enableTLSForSentinelMode && this.options.tls) {
+            Object.assign(resolved, this.options.tls)
+            this.stream = createTLSConnection(resolved)
           } else {
-            _this.stream = createConnection(resolved)
+            this.stream = createConnection(resolved)
           }
-          _this.sentinelIterator.reset(true)
-          callback(null, _this.stream)
+          this.sentinelIterator.reset(true)
+          resolve(this.stream)
         } else {
-          const endpointAddress = endpoint.host + ':' + endpoint.port
+          const endpointAddress = endpoint.value.host + ':' + endpoint.value.port
           const errorMsg = err
             ? 'failed to connect to sentinel ' + endpointAddress + ' because ' + err.message
             : 'connected to sentinel ' + endpointAddress + ' successfully, but got an invalid reply: ' + resolved
@@ -132,13 +136,15 @@ export default class SentinelConnector extends AbstractConnector {
           if (err) {
             lastError = err
           }
-          connectToNext()
+          resolve(connectToNext())
         }
       })
-    }
+    });
+
+    return connectToNext();
   }
 
-  private updateSentinels (client, callback: NodeCallback): void {
+  private updateSentinels (client, callback: CallbackFunction): void {
 
     if (!this.options.updateSentinels) {
       return callback(null)
@@ -167,7 +173,7 @@ export default class SentinelConnector extends AbstractConnector {
     })
   }
 
-  private resolveMaster (client, callback: NodeCallback<ITcpConnectionOptions>): void {
+  private resolveMaster (client, callback: CallbackFunction<ITcpConnectionOptions>): void {
     client.sentinel('get-master-addr-by-name', this.options.name, (err, result) => {
       if (err) {
         client.disconnect()
@@ -186,7 +192,7 @@ export default class SentinelConnector extends AbstractConnector {
     })
   }
 
-  private resolveSlave (client, callback: NodeCallback<ITcpConnectionOptions | null>): void {
+  private resolveSlave (client, callback: CallbackFunction<ITcpConnectionOptions | null>): void {
     client.sentinel('slaves', this.options.name, (err, result) => {
       client.disconnect()
       if (err) {
@@ -214,7 +220,7 @@ export default class SentinelConnector extends AbstractConnector {
     return this.options.natMap[`${item.host}:${item.port}`] || item
   }
 
-  private resolve (endpoint, callback: NodeCallback<ITcpConnectionOptions>): void {
+  private resolve (endpoint, callback: CallbackFunction<ITcpConnectionOptions>): void {
     var client = new Redis({
       port: endpoint.port || 26379,
       host: endpoint.host,

lib/connectors/StandaloneConnector.ts

@@ -2,6 +2,7 @@ import {createConnection, TcpNetConnectOpts, IpcNetConnectOpts} from 'net'
 import {connect as createTLSConnection, SecureContextOptions} from 'tls'
 import {CONNECTION_CLOSED_ERROR_MSG} from '../utils'
 import AbstractConnector, {ErrorEmitter} from './AbstractConnector'
+import * as PromiseContainer from '../promiseContainer';
 import {NetStream} from '../types'
 
 export function isIIpcConnectionOptions (value: any): value is IIpcConnectionOptions {
@@ -21,7 +22,7 @@ export default class StandaloneConnector extends AbstractConnector {
     super()
   }
 
-  public connect (callback: Function, _: ErrorEmitter) {
+  public connect (_: ErrorEmitter) {
     const {options} = this
     this.connecting = true
 
@@ -46,27 +47,28 @@ export default class StandaloneConnector extends AbstractConnector {
     if (options.tls) {
       Object.assign(connectionOptions, options.tls)
     }
+
+    const _Promise = PromiseContainer.get();
+    return new _Promise<NetStream>((resolve, reject) => {
+      process.nextTick(() => {
+        if (!this.connecting) {
+          reject(new Error(CONNECTION_CLOSED_ERROR_MSG))
+          return
+        }
 
-    process.nextTick(() => {
-      if (!this.connecting) {
-        callback(new Error(CONNECTION_CLOSED_ERROR_MSG))
-        return
-      }
-
-      let stream: NetStream
-      try {
-        if (options.tls) {
-          stream = createTLSConnection(connectionOptions)
-        } else {
-          stream = createConnection(connectionOptions)
+        try {
+          if (options.tls) {
+            this.stream = createTLSConnection(connectionOptions)
+          } else {
+            this.stream = createConnection(connectionOptions)
+          }
+        } catch (err) {
+          reject(err)
+          return
         }
-      } catch (err) {
-        callback(err)
-        return
-      }
 
-      this.stream = stream
-      callback(null, stream)
+        resolve(this.stream)
+      })
     })
   }
 }

lib/index.ts

@@ -1,10 +1,19 @@
 exports = module.exports = require('./redis').default
 
-export {ReplyError} from 'redis-errors'
-export const Cluster = require('./cluster').default
-export const Command = require('./command').default
-export const ScanStream = require('./ScanStream').default
-export const Pipeline = require('./pipeline').default
+export {default} from './redis';
+export {default as Cluster} from './cluster'
+export {default as Command} from './command'
+export {default as ScanStream} from './ScanStream'
+export {default as Pipeline} from './pipeline'
+export {default as AbstractConnector} from './connectors/AbstractConnector'
+export {default as SentinelConnector, SentinelIterator} from './connectors/SentinelConnector'
+
+// Type Exports
+export {ISentinelAddress} from './connectors/SentinelConnector'
+export {IRedisOptions} from './redis/RedisOptions'
+
+// No TS typings
+export const ReplyError = require('redis-errors').ReplyError
 
 const PromiseContainer = require('./promiseContainer')
 Object.defineProperty(exports, 'Promise', {

lib/redis/RedisOptions.ts

@@ -1,10 +1,12 @@
 import {ISentinelConnectionOptions} from '../connectors/SentinelConnector';
+import AbstractConnector from '../connectors/AbstractConnector';
 import {IClusterOptions} from '../cluster/ClusterOptions';
 import {ICommanderOptions} from '../commander';
 
 export type ReconnectOnError = (err: Error) => boolean | 1 | 2;
 
 export interface IRedisOptions extends Partial<ISentinelConnectionOptions>, Partial<ICommanderOptions>, Partial<IClusterOptions> {
+    connector?: AbstractConnector,
     retryStrategy?: (times: number) => number | void | null,
     keepAlive?: number,
     noDelay?: boolean,

lib/redis/event_handler.ts

@@ -54,7 +54,7 @@ export function connectHandler(self) {
           }
         } else {
           self.serverInfo = info;
-          if (self.connector.check(info)) {
+          if (self.options.connector.check(info)) {
             exports.readyHandler(self)();
           } else {
             self.disconnect(true);