docker-compose -f stack.yml up

mongo_1          | Successfully added user: {
mongo_1          |     "user" : "root",
mongo_1          |     "roles" : [
mongo_1          |         {
mongo_1          |             "role" : "root",
mongo_1          |             "db" : "admin"
mongo_1          |         }
mongo_1          |     ]
mongo_1          | }

$ mongo -u root -p
MongoDB shell version v3.6.3
Enter password: 
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 4.0.5
2019-02-05T15:36:35.846+0300 E QUERY    [thread1] Error: Authentication failed. :
DB.prototype._authOrThrow@src/mongo/shell/db.js:1608:20
@(auth):6:1
@(auth):1:2
exception: login failed

019-02-05T15:39:14.729+0300 E QUERY    [thread1] Error: couldn't add user: command createUser requires authentication :

$ mongo -u root -p

$ mongo  --host mongo -u root -p

$ cat docker-compose.yml
version: '3.1'
services:
  mongo:
    image: 'mongo:latest'
    volumes:
      - './etc/mongo/mongod.conf:/etc/mongo.conf'
      - './data/db:/data/db'
    ports:
      - '27017:27017'
    environment:
      - MONGO_DATA_DIR=/data/db
      - MONGO_INITDB_ROOT_USERNAME=root
      - MONGO_INITDB_ROOT_PASSWORD=12345678

$ cat ./etc/mongo/mongod.conf 
# mongod.conf

# for documentation of all options, see:
#    http://docs.mongodb.org/manual/reference/configuration-options/ 

# Where and how to store data.
storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true
#  engine:
#  mmapv1:
#  wiredTiger:

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongod.log

# network interfaces
net:
  port: 27017
  bindIp: 0.0.0.0


# how the process runs
processManagement:
  timeZoneInfo: /usr/share/zoneinfo

security:
  authorization: enabled

#operationProfiling:

#replication:

#sharding:

## Enterprise-Only Options:

#auditLog:

#snmp: