If you are using the official mongo image, you can check it's source in github here.

The default command used is mongod, which can be overriden with the --auth switch;

docker run -d ... mongodb:latest mongo --auth

If you need to create the user, then we have to override the /entrypoint.sh startup script.

docker run -d ... -v $PWD/new_entrypoint.sh:/entrypoint.sh mongodb:latest

Docker Compose

mongo:
    image: mongo:latest
    command: ["mongod", "--auth"]
    expose: "27017"
    ports: "27017:27017"
    volumes:
        - $(cwd)/new_entrypoint.sh:/entrypoint.sh

Execute file

http://stackoverflow.com/questions/4881208/how-to-put-username-password-in-mongodb

Start mongo with auth:

$ mongod --auth

Access admin database, execute file:

$ mongod admin 'create_user.js'

db.createUser({user:"admin_name", pwd:"1234",roles:["readWrite","dbAdmin"]})

Entrypoint

The entrypoint script:

#!/bin/bash
set -e

if [ "${1:0:1}" = '-' ]; then
	set -- mongod "$@"
fi

if [ "$1" = 'mongod' ]; then
	chown -R mongodb /data/db

	numa='numactl --interleave=all'
	if $numa true &> /dev/null; then
		set -- $numa "$@"
	fi

	exec gosu mongodb "$@"
fi

exec "$@"

We need to create a user and password:

#!/bin/bash
mongo
use admin
db.createUser({user:"$MONGO_ADMIN_USERNAME", pwd:"$MONGO_ADMIN_PASSWORD", roles:["root", "admin"]});

http://stackoverflow.com/questions/34559557/how-to-enable-authentication-on-mongodb-through-docker http://stackoverflow.com/questions/35772977/authentication-issue-in-docker-mongodb