CODEWITHSUNDEEP
javascriptdockerdocker-compose
Mihai Perju
Mihai Perju

Reputation: 25

Cannot make HTTP requests between docker containers

I have 2 apps running as services under docker-compose.

  1. React App
  2. Node.js server

I am trying to make an HTTP request from my React app to the Node.js server by calling: fetch("http://backend:4000/")

I get GET http://backend:4000/ net::ERR_NAME_RESOLUTION_FAILED in the browser when I access my React app under http://localhost:3000

This is my docker-compose file.

version: "3.7"

services:
  frontend:
    build:
      context: ./frontend
    volumes:
      - ./frontend:/app
    ports:
      - "3000:3000"
    depends_on:
      - "backend"

  backend:
    build:
      context: ./backend
    volumes:
      - ./backend:/app

I'm running Ubuntu and I have been having this problem for ages. Nothing really helps - creating a network and assigning services to them, creating links and many others.

One curious thing is that when I get into the React app container and I run bash command: ping backend or curl http://backend:4000, the request actually works fine.

Upvotes: 0

Views: 6273

Answers (2)

naltun
naltun

Reputation: 134

My guess is that, you are trying to connect your backend app through your browser not through frontend container. If that is the case, then you should reveal the backend port like;

  backend:
    container_name: backend
    build:
      context: ./backend
    volumes:
      - ./backend:/app
    ports:  #whatever the port number
      - "4000:4000"

then you should change the url from http://backend:4000 to http://localhost:4000 on your react app.

Upvotes: 2

JClarke
JClarke

Reputation: 808

version: "3.7"

services:
  frontend:
    build:
      context: ./frontend
    volumes:
      - ./frontend:/app
    ports:
      - "3000:3000"
    depends_on:
      - "backend"
    links:
      - backend

  backend:
    container_name: backend
    build:
      context: ./backend
    volumes:
      - ./backend:/app

Incorrect option

links:
  - "backend:test"

"backend:test" is the reason you're getting a name resolution error. That is not the service name, backend is.

Upvotes: 0

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