CODEWITHSUNDEEP
node.jsdockerdocker-composeredis
ino
ino

Reputation: 1125

Redis error "EHOSTUNREACH" when trying to connect from Node JS in docker compose

I am trying to connect to redis from node js in docker, but I am facing an error. Redis container starts successfully and I can ping with redis-cli. I think the problem might be somewhere else. The below code and configuration works on ubuntu 20.04, but shows error on arch linux (Docker version 20.10.17):

Redis Client Error Error: connect EHOSTUNREACH 172.18.0.2:6379
at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1237:16) {
   errno: -113,
   code: 'EHOSTUNREACH',
   syscall: 'connect',
   address: '172.18.0.2',
   port: 6379
}

Here is my docker compose file:

version: "3.7"

services:
  app:
    image: node:18.4-alpine
    command: sh -c "yarn run dev"
    ports:
      - "4000:4000"
    working_dir: /app
    volumes:
      - ./:/app
    env_file:
      - ./.env

  redis:
    image: redislabs/rejson:latest
    ports:
      - "6379:6379"

Here, I am trying to connect to redis from nodejs (node-redis 4.1.1):

const socket = {
  host: "redis",
  port: 6379
}

export const redisClient = createClient({
  socket,
  database: 0,
  legacyMode: true
})

redisClient.on("error", (err) => {
  console.log("Redis Client Error", err)
});

Upvotes: 1

Views: 1483

Answers (1)

zer0
zer0

Reputation: 2919

This is probably a race condition. Can you add depends_on: redis to your app service? This will at least make sure that the redis service is Running before instantiating the application.

Also, it is good practice to add retry/wait loop in your application with a timeout for external connectivity for better resilience to such race condition problems. They are very common.

Upvotes: 1

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