docker-compose mongodb fresh instance not working - mongodb

Question

Trying to bring docker-compose up with the following:
version: '3.1'
services:
mongo:
image: mongo
container_name: mongo-db
networks:
- mongo
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: ${MONGO_ROOT_USER}
MONGO_INITDB_ROOT_PASSWORD: ${MONGO_ROOT_PASSWORD}
MONGO_INITDB_DATABASE: ${MONGO_INITDB_DATABASE}
ports:
- 27017:27017
volumes:
- ./mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro
mongo-express:
image: mongo-express:latest
container_name: mongo-express
restart: always
networks:
- mongo
depends_on:
- mongo
ports:
- 8081:8081
environment:
ME_CONFIG_MONGODB_SERVER: mongo
ME_CONFIG_MONGODB_PORT: 27017
ME_CONFIG_MONGODB_ADMINUSERNAME: ${MONGO_ROOT_USER}
ME_CONFIG_MONGODB_ADMINPASSWORD: ${MONGO_ROOT_PASSWORD}
The entry point js file as below:
db.createUser(
{
user: "dba",
pwd: "dba",
roles: [
{
role: "readWrite",
db: "mydb"
}
]
}
);
The variables are defined in .env file as below:
MONGO_ROOT_USER=root
MONGO_ROOT_PASSWORD=root
MONGO_INITDB_DATABASE=mydb
MONGOEXPRESS_LOGIN=dev
MONGOEXPRESS_PASSWORD=dev
When I login to mongo-express, I don't see the user or the db that is created by mongo-init.js
Also, I can't login if I try to connect using:
docker exec -it mongo-db mongo --username dba
However, if I use the following I can connect but still don't see mydb when I run show dbs:
docker exec -it mongo-db mongo --username root
What's happening here?
Thanks in advance

Answer 1

I think you need to change the env to:
MONGO_INITDB_ROOT_USERNAME
MONGO_INITDB_ROOT_PASSWORD
These variables, used in conjunction, create a new user and set that
user's password. This user is created in the admin authentication
database and given the role of root, which is a "superuser" role.
see the Docs
another note:
if you do not insert data with your JavaScript files, then no database is created.
MONGO_INITDB_DATABASE
This variable allows you to specify the name of a database to be used
for creation scripts in /docker-entrypoint-initdb.d/*.js (see
Initializing a fresh instance below). MongoDB is fundamentally
designed for "create on first use", so if you do not insert data with
your JavaScript files, then no database is created.