docker tomcat connection database problem

Question

Have docker tomcat application on first docker container. And can't connect to mongo in another container. Pls Help!

Tomcat application dataSource:

spring:
  data:
    mongodb:
      host: mongo1
      port: 27017
      database: open-data

Docker-compose file:

version: '3.3'
services:
  mongo:
    image: mongo
    container_name: mongo1
    environment:
      MONGO_INITDB_DATABASE: open-data
    ports:
      - 27017:27017

Answer 1

In docker documentation I can't see that container_name is used to define host name of service in the docker-compose network.

You must use mongo instead of mongo1 as it's the name of your service.

spring:
  data:
    mongodb:
      host: mongo
      port: 27017
      database: open-data

All you need about networking is here :
https://docs.docker.com/compose/networking/

version: '3.3'
services:
  mongo: # <= this is used to define host name

If you did provide your entire docker compose file, you must add tomcat container definition in the same docker-compose with mongo for them to be in the same network.