@watashino/redis

A reusable NestJS module for Redis supporting Standalone, Cluster, and Sentinel modes with easy-to-use provider for injection.

Overview

The @watashino/redis package provides a NestJS module for Redis that supports three different modes of operation:

1. Standalone - Connect to a single Redis instance
2. Cluster - Connect to a Redis cluster for high availability and scalability
3. Sentinel - Connect to Redis using Sentinel for high availability

This module uses ioredis under the hood and provides a simple way to inject and use Redis in your NestJS application.

Installation

npm install @watashino/redis ioredis

or

yarn add @watashino/redis ioredis

Usage

Basic Usage

Import the RedisModule in your application module:

import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';
import { RedisModule } from '@watashino/redis';

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true,
    }),
    RedisModule,
  ],
})
export class AppModule {}

Then inject the RedisClient in your services:

import { Injectable } from '@nestjs/common';
import { RedisClient } from '@watashino/redis';

@Injectable()
export class AppService {
  constructor(private readonly redisClient: RedisClient) {}

  async setValue(key: string, value: string): Promise<string> {
    return this.redisClient.set(key, value);
  }

  async getValue(key: string): Promise<string | null> {
    return this.redisClient.get(key);
  }
}

Working with Complex Objects

When working with complex objects, you need to serialize and deserialize them:

import { Injectable } from '@nestjs/common';
import { RedisClient } from '@watashino/redis';

@Injectable()
export class AppService {
  constructor(private readonly redisClient: RedisClient) {}

  async setObject(key: string, value: Record<string, any>): Promise<string> {
    return this.redisClient.set(key, JSON.stringify(value));
  }

  async getObject<T>(key: string): Promise<T | null> {
    const data = await this.redisClient.get(key);
    if (!data) return null;
    return JSON.parse(data) as T;
  }
}

Configuration

The Redis module is configured using environment variables. The following environment variables are supported:

Common Environment Variables

Variable	Description	Default	Required
REDIS_MODE	Redis mode: 'standalone', 'cluster', or 'sentinel'	-	Yes
REDIS_PASSWORD	Redis password	-	No
REDIS_DB	Redis database number	0	No
REDIS_TLS	Whether to use TLS for Redis connections	false	No

Standalone Mode Environment Variables

Variable	Description	Default	Required
REDIS_HOST	Redis host	-	Yes
REDIS_PORT	Redis port	-	Yes

Cluster Mode Environment Variables

Variable	Description	Default	Required
REDIS_NODES	Comma-separated list of Redis nodes (format: host:port,host:port)	-	Yes
REDIS_CLUSTER_MAX_REDIRECTIONS	Maximum number of redirections for cluster mode	16	No

Sentinel Mode Environment Variables

Variable	Description	Default	Required
REDIS_NODES	Comma-separated list of Redis sentinel nodes (format: host:port,host:port)	-	Yes
REDIS_SENTINEL_NAME	The name of the sentinel	-	Yes

Examples

Standalone Mode

REDIS_MODE=standalone
REDIS_HOST=localhost
REDIS_PORT=6379
REDIS_PASSWORD=mypassword
REDIS_DB=0

Cluster Mode

REDIS_MODE=cluster
REDIS_NODES=localhost:6379,localhost:6380,localhost:6381,localhost:6382,localhost:6383,localhost:6384
REDIS_PASSWORD=mypassword
REDIS_DB=0
REDIS_CLUSTER_MAX_REDIRECTIONS=16

Sentinel Mode

REDIS_MODE=sentinel
REDIS_NODES=localhost:26379,localhost:26380,localhost:26381
REDIS_SENTINEL_NAME=mymaster
REDIS_PASSWORD=mypassword
REDIS_DB=0

API Reference

The RedisClient class extends the Commander class from ioredis, which provides all the Redis command methods. Here are some of the most commonly used methods:

Basic Operations

• set(key, value, [options]) - Set a key-value pair
• get(key) - Get the value of a key
• del(key) - Delete a key
• exists(key) - Check if a key exists
• expire(key, seconds) - Set a key's time to live in seconds
• ttl(key) - Get the time to live for a key in seconds

Hash Operations

• hset(key, field, value) - Set the value of a hash field
• hget(key, field) - Get the value of a hash field
• hdel(key, field) - Delete a hash field
• hgetall(key) - Get all the fields and values in a hash

List Operations

• lpush(key, value) - Prepend a value to a list
• rpush(key, value) - Append a value to a list
• lpop(key) - Remove and get the first element in a list
• rpop(key) - Remove and get the last element in a list
• lrange(key, start, stop) - Get a range of elements from a list

Set Operations

• sadd(key, member) - Add a member to a set
• srem(key, member) - Remove a member from a set
• smembers(key) - Get all the members in a set
• sismember(key, member) - Check if a member is in a set

Sorted Set Operations

• zadd(key, score, member) - Add a member to a sorted set
• zrem(key, member) - Remove a member from a sorted set
• zrange(key, start, stop) - Get a range of members from a sorted set
• zrank(key, member) - Get the rank of a member in a sorted set

Connection Operations

• ping() - Ping the server
• quit() - Close the connection
• info() - Get information and statistics about the server

For a complete list of available methods, refer to the ioredis documentation.

License

MIT