access nodejs hosted in docker container in another container using web application

Question

I have 3 containers running:

1. nodejs
2. tomcat
3. mysql

tomcat container is able to connect to mysql. node is able to connect to mysql.

However when tomcat container tries to connect to node on a http request using node-container-id:3004/3333 as hostname:port OR node-container-internal-ip:3004/3333 as hostip:port , it keeps giving 404 error.

My docker-compose.yml is as follows:

version: '2.1'

services:

  openmrs-referenceapplication-mysql:
    restart: "always"
    image: mysql:5.7
    ports:
      - 3333:3306
    command: "mysqld --character-set-server=utf8 --collation-server=utf8_general_ci"
    environment:
      MYSQL_DATABASE: ${MYSQL_DB:-openmrs}
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD:-root-pass}
      MYSQL_USER: ${MYSQL_USER:-openmrs_user}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD:-my-pass}
    healthcheck:
      test: "exit 0"
    volumes:
      - openmrs-referenceapplication-mysql-data:/var/lib/mysql

  openmrs-referenceapplication-node:
    restart: "always"
    image: node:12.20.1
    depends_on :
      - openmrs-referenceapplication-mysql
    expose:
      - "3004"
    ports:
      - "3009:3004"
    links:
      - openmrs-referenceapplication-mysql
      - openmrs-referenceapplication
    environment:
      DB_DATABASE: ${MYSQL_DB:-my-db}
      DB_HOST: openmrs-referenceapplication-mysql
      DB_USERNAME: ${MYSQL_USER:-root}
      DB_PASSWORD: ${MYSQL_PASSWORD:-my-pass}
    volumes:
     - openmrs-referenceapplication-node-data:/home/azureuser/my-dir
     - ./Mydir:/Mydir
    command: node ./Mydir/bin/www


  openmrs-referenceapplication:
    restart: "always"
    image: openmrs/openmrs-reference-application-distro:2.8.0
    depends_on:
      - openmrs-referenceapplication-mysql
    ports:
      - "8001:8080"
    links:
      - openmrs-referenceapplication-mysql
    environment:
      DB_DATABASE: ${MYSQL_DB:-openmrs}
      DB_HOST: openmrs-referenceapplication-mysql
      DB_USERNAME: ${MYSQL_USER:-openmrs_user}
      DB_PASSWORD: ${MYSQL_PASSWORD:-my-pass}
      DB_CREATE_TABLES: 'true'
      DB_AUTO_UPDATE: 'true'
      MODULE_WEB_ADMIN: 'true'
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:8080/openmrs/"]
      timeout: 20s
    volumes:
      - openmrs-referenceapplication-data:/usr/local/tomcat/.OpenMRS/
      - /usr/local/tomcat/.OpenMRS/modules/ # do not store modules in data
      - /usr/local/tomcat/.OpenMRS/owa/ # do not store owa in data
      - ./webservices.rest-2.29.0.omod://usr/local/tomcat/.OpenMRS/modules/webservices.rest-2.29.0.omod
      - /var/lib/tomcat8/webapps/ROOT.war:/usr/local/tomcat/webapps/ROOT
     
volumes:
   openmrs-referenceapplication-mysql-data:
   openmrs-referenceapplication-data:
   openmrs-referenceapplication-node-data:

Any idea what am I missing?

Thanks

Answer 1

Ey !

Your container can be reached with the service name (and only this). So if you want to reach your node container from another one you have to enter this adress: http://openmrs-referenceapplication-node/<sub_path> . To reach your service outside your container (on your local machine), you just have to go to: localhost:3009 , in your case.

The best way to tackle conectivity issues is to enter the container and try to ping the container you target. Moreover you should use a more recent version of compose with networks instead of links .