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

The official mongo image has merged a PR to include the functionality to create users and databases at startup.

The database initialisation will run when there is nothing populated in the /data/db directory.

Admin User Setup

The environment variables to control "root" user setup are

• MONGO_INITDB_ROOT_USERNAME
• MONGO_INITDB_ROOT_PASSWORD

Example

docker run -d \
  -e MONGO_INITDB_ROOT_USERNAME=admin \
  -e MONGO_INITDB_ROOT_PASSWORD=password \
  mongod

You don't need to/can't use --auth on the command line as the docker entrypoint.sh script adds this in when the environment variables exist.

Database Initialisation

The image also provides the /docker-entrypoint-initdb.d/ path to deploy custom .js or .sh setup scripts that will be run once on database initialisation. .js scripts will be run against test by default or MONGO_INITDB_DATABASE if defined in the environment.

COPY mysetup.sh /docker-entrypoint-initdb.d/

or

COPY mysetup.js /docker-entrypoint-initdb.d/

A simple initialisation mongo shell javascript file that demonstrates setting up the container collection with data, logging and how to exit with an error (for result checking).

let error = true

let res = [
  db.container.drop(),
  db.container.createIndex({ myfield: 1 }, { unique: true }),
  db.container.createIndex({ thatfield: 1 }),
  db.container.createIndex({ thatfield: 1 }),
  db.container.insert({ myfield: 'hello', thatfield: 'testing' }),
  db.container.insert({ myfield: 'hello2', thatfield: 'testing' }),
  db.container.insert({ myfield: 'hello3', thatfield: 'testing' }),
  db.container.insert({ myfield: 'hello3', thatfield: 'testing' }),
  db.other.
]

printjson(res)

if (error) {
  print('Error, exiting')
  quit(1)
}