Store a value in redis store using Nestjs - redis

Question

I have a simple nestjs application, where I have set up a CacheModule using Redis store as follows:
import * as redisStore from 'cache-manager-redis-store';
CacheModule.register({
store: redisStore,
host: 'redis',
port: 6379,
}),
I would like to use it to store a single value, however, I do not want to do it the built-in way by attaching an interceptor to a controller method, but instead I want to control it manually and be able to set and retrieve the value in the code.
How would I go about doing that and would I even use cache manager for that?

Answer 1

You can use the official way from Nest.js:
1. Create your RedisCacheModule:
1.1. redisCache.module.ts:
import { Module, CacheModule } from '#nestjs/common';
import { ConfigModule, ConfigService } from '#nestjs/config';
import * as redisStore from 'cache-manager-redis-store';
import { RedisCacheService } from './redisCache.service';
#Module({
imports: [
CacheModule.registerAsync({
imports: [ConfigModule],
inject: [ConfigService],
useFactory: async (configService: ConfigService) => ({
store: redisStore,
host: configService.get('REDIS_HOST'),
port: configService.get('REDIS_PORT'),
ttl: configService.get('CACHE_TTL'),
}),
}),
],
providers: [RedisCacheService],
exports: [RedisCacheService] // This is IMPORTANT, you need to export RedisCacheService here so that other modules can use it
})
export class RedisCacheModule {}
1.2. redisCache.service.ts:
import { Injectable, Inject, CACHE_MANAGER } from '#nestjs/common';
import { Cache } from 'cache-manager';
#Injectable()
export class RedisCacheService {
constructor(
#Inject(CACHE_MANAGER) private readonly cache: Cache,
) {}
async get(key) {
await this.cache.get(key);
}
async set(key, value) {
await this.cache.set(key, value);
}
}
2. Inject RedisCacheModule wherever you need it:
Let's just assume we will use it in module DailyReportModule:
2.1. dailyReport.module.ts:
import { Module } from '#nestjs/common';
import { RedisCacheModule } from '../cache/redisCache.module';
import { DailyReportService } from './dailyReport.service';
#Module({
imports: [RedisCacheModule],
providers: [DailyReportService],
})
export class DailyReportModule {}
2.2. dailyReport.service.ts
We will use the redisCacheService here:
import { Injectable, Logger } from '#nestjs/common';
import { Cron } from '#nestjs/schedule';
import { RedisCacheService } from '../cache/redisCache.service';
#Injectable()
export class DailyReportService {
private readonly logger = new Logger(DailyReportService.name);
constructor(
private readonly redisCacheService: RedisCacheService, // REMEMBER TO INJECT THIS
) {}
#Cron('0 1 0 * * *') // Run cron job at 00:01:00 everyday
async handleCacheDailyReport() {
this.logger.debug('Handle cache to Redis');
}
}
You can check my sample code here.

Answer 2

Building on Ahmad's comment above, I used the following to enable redis in my nestjs application:
Install and setup nestjs-redis https://www.npmjs.com/package/nestjs-redis per docs.
See the docs here on how to write and read values in a Redis store:
https://github.com/NodeRedis/node-redis

Answer 3

If you're connection a external Redis, I recommend to use 'async-redis' package.
The code will be:
import * as redis from 'async-redis';
import redisConfig from '../../config/redis';
On redisConfig:
export default {
host: 'your Host',
port: parseInt('Your Port Conection'),
// Put the first value in hours
// Time to expire a data on redis
expire: 1 * 60 * 60,
auth_pass: 'password',
};
So, you run:
var dbConnection = redis.createClient(config.db.port, config.db.host,
{no_ready_check: true});
Now you can, execute commands like set and get for your Redis Database.