How to create a DB for MongoDB container on start up?

Question

I am working with Docker and I have a stack with PHP, MySQL, Apache and Redis. I need to add MongoDB now so I was checking the Dockerfile for the latest version and also the docker-entrypoint.sh file from the MongoDB Dockerhub but I couldn't find a way to setup a default DB, admin user/password and possibly auth method for the container from a docker-compose.yml file.

In MySQL you can setup some ENV variables as for example:

db:
    image: mysql:5.7
    env_file: .env
    environment:
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
      MYSQL_DATABASE: ${MYSQL_DATABASE}
      MYSQL_USER: ${MYSQL_USER}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD}

And this will setup the DB and the user/password as the root password.

Is there any way to achieve the same with MongoDB? Anyone has some experience or workaround?

Answer 1

Here another cleaner solution by using docker-compose and a js script.

This example assumes that both files (docker-compose.yml and mongo-init.js) lay in the same folder.

docker-compose.yml

version: '3.7'

services:
    mongodb:
        image: mongo:latest
        container_name: mongodb
        restart: always
        environment:
            MONGO_INITDB_ROOT_USERNAME: <admin-user>
            MONGO_INITDB_ROOT_PASSWORD: <admin-password>
            MONGO_INITDB_DATABASE: <database to create>
        ports:
            - 27017:27017
        volumes:
            - ./mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro

mongo-init.js

db.createUser(
        {
            user: "<user for database which shall be created>",
            pwd: "<password of user>",
            roles: [
                {
                    role: "readWrite",
                    db: "<database to create>"
                }
            ]
        }
);

Then simply start the service by running the following docker-compose command

docker-compose up --build -d mongodb 

Note: The code in the docker-entrypoint-init.d folder is only executed if the database has never been initialized before.