CODEWITHSUNDEEP
node.jsmongodbdockerdocker-compose
quartaela
quartaela

Reputation: 2757

docker-compose wait-for.sh fails for waiting mongodb

I am trying to set up a docker network with simple nodejs and mongodb services by following this guide, however, when building nodejs it fails because it can't connect to mongodb.

docker-compose.yml

version: "3"
services:
  nodejs:
    container_name: nodejs # How the container will appear when listing containers from the CLI
    image: node:10 # The <container-name>:<tag-version> of the container, in this case the tag version aligns with the version of node
    user: node # The user to run as in the container
    working_dir: "/app" # Where to container will assume it should run commands and where you will start out if you go inside the container
    networks:
      - app # Networking can get complex, but for all intents and purposes just know that containers on the same network can speak to each other
    ports:
      - "3000:3000" # <host-port>:<container-port> to listen to, so anything running on port 3000 of the container will map to port 3000 on our localhost
    volumes:
      - ./:/app # <host-directory>:<container-directory> this says map the current directory from your system to the /app directory in the docker container
    command: # The command docker will execute when starting the container, this command is not allowed to exit, if it does your container will stop
      - ./wait-for.sh
      - --timeout=15
      - mongodb:27017
      - --
      - bash
      - -c
      - npm install && npm start
    env_file: ".env"
    environment: 
      - MONGO_USERNAME=$MONGO_USERNAME
      - MONGO_PASSWORD=$MONGO_PASSWORD
      - MONGO_HOSTNAME=mongodb
      - MONGO_PORT=$MONGO_PORT
      - MONGO_DB=$MONGO_DB
    depends_on:
      - mongodb

  mongodb:
    image: mongo:4.1.8-xenial
    container_name: mongodb
    restart: unless-stopped
    env_file: .env
    environment:
      - MONGO_INITDB_ROOT_USERNAME=$MONGO_USERNAME
      - MONGO_INITDB_ROOT_PASSWORD=$MONGO_PASSWORD
    volumes:  
      - dbdata:/data/db 
    networks:
      - app

networks:
  app:
   driver: bridge

volumes:
  dbdata:

app.js

const express = require('express');
var server = express();
var bodyParser = require('body-parser');

// getting-started.js
var mongoose = require('mongoose');
mongoose.connect('mongodb://simpleUser:123456@mongodb:27017/simpleDb', {useNewUrlParser: true});

server.listen(3000, function() {
  console.log('Example app listening on port 3000');
});

Here is the common wait-for.sh script that I was using. https://github.com/eficode/wait-for/blob/master/wait-for

docker logs -f nodejs gives;

Operation timed out

Thanks for your help!

Upvotes: 1

Views: 3420

Answers (2)

Kārlis Ābele
Kārlis Ābele

Reputation: 1021

In this case I believe the issue is that you are using the wait-for.sh script which makes use of netcat command (see https://github.com/eficode/wait-for/blob/master/wait-for#L24), but the node:10 image does not have netcat installed...

I would suggest either creating a custom image based on the node:10 image and adding netcat or use a different approach (preferably a nodejs based solution) for checking if the mongodb is accessible

A sample Dockerfile for creating your own custom image would look something like this

FROM node:10

RUN apt update && apt install -y netcat

Then you can build this image by replacing image: node:10 with 

build: 
  dockerfile: Dockerfile
  context: .

and you should be fine

Upvotes: 4

quartaela
quartaela

Reputation: 2757

I found the problem which was because of the image node:10 doesn't have nc command installed so it was failing. I switched to image node:10-alpine and it worked.

Upvotes: 0

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