I’m struggling to connect a redis deployment to my nodejs app. Of course locally without the use of docker, it works well, so I’m at odds as to whether this is an issue to do with my code, or the way I’ve set up my docker compose file
Dockerfile:
FROM node:8
WORKDIR /app
COPY package.json /app
COPY . /app
RUN npm install
CMD ["npm", "start"]
EXPOSE 3000
docker-compose.yml
version: "3"
services:
web:
container_name: web-container
restart: always
depends_on:
- redis
build: .
ports:
- "3000:3000"
links:
- redis
redis:
container_name: redis-container
image: "redis:latest"
ports:
- "6379:6379"
volumes:
- ./data:/data
Redis Connection File (RedisService.js)
const redis = require("redis");
const client = redis.createClient();
const DbUtils = require("../../db_utils");
const {promisify} = require("util");
const getAsync = promisify(client.get).bind(client);
const existsAsync = promisify(client.exists).bind(client);
class RedisCache {
constructor () {
var connected;
// * Initiliase the connection to redis server
client.on("connect", () => {console.log("📒 Redis cache is ready"); connected = true;})
client.on("error", (e) => {console.log("Redis cache error:n" + e); connected = false;});
}
async setData (id, data) {
// * Stringify data if it's an object
data = data instanceof Object ? JSON.stringify(data) : data;
client.set(id, data);
return true;
}
async getData (key) {
return getAsync(key).then(data => {
data = JSON.parse(data) instanceof Object ? JSON.parse(data) : data;
return data;
})
}
async exists (key) {
return existsAsync(key).then(bool => {
return bool;
})
}
// Returns status of redis cache
async getStatus () {
return this.connected;
}
}
module.exports = new RedisCache();
ERROR
Error: Redis connection to 127.0.0.11:6379 failed – connect ECONNREFUSED 127.0.0.11:6379
2
Answers
When you run your containers via
docker-compose
they are all connected to a common network. Service name is a DNS name of given container so to accessredis
container fromweb
you should create the client like :You have not configured the host so it uses the default one –
127.0.0.1
. But from the point of view of yourweb
container the redis is not running on the localhost. Instead it runs in it’s own container which DNS name isredis
.The beginning (docker part) of this tutorial worked for me :
https://medium.com/geekculture/using-redis-with-docker-and-nodejs-express-71dccd495fd3
then in the node server (like in official redis website example) :