Cannot connect to MongoDB outside the docker - mongodb

Question

I've got the following docker compose file with MongoDB container:
version: '3.6'
services:
mongo:
image: mongo
volumes:
- ./keyfile.txt:/data/keyfile.txt
entrypoint:
- bash
- -c
- |
cp /data/keyfile.txt /data/replica.key
chmod 400 /data/replica.key
chown 999:999 /data/replica.key
exec docker-entrypoint.sh $$#
command: "--bind_ip_all --replSet rs0 --keyFile /data/replica.key"
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: example
healthcheck:
test: test $$(echo "rs.initiate().ok || rs.status().ok" | mongo -u root -p example --quiet) -eq 1
interval: 10s
retries: 3
network_mode: host
I have to get rid of network_mode: host, so I changed it to
ports:
- "27017:27017"
After that change, I'm not able to connect to the mongo outside of the docker network.
I'm trying to connect to the database using Compass with the following URI:
mongodb://root:example#localhost:27017/?authMechanism=DEFAULT
How to fix that?

Answer 1

This is fully working example.
I'm recommending to create custom DB and custom user instead of using root user.
Use special path of auto-executing queries and create one or multiple databases.
mongodb:
image: mongo:latest
restart: always
ports:
- "27017:27017"
volumes:
- ./var/mongodb:/data/db
- ./mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: pass
mongo-init.js
db = db.getSiblingDB('SOME_DB');
db.createUser({
user: 'some_db_user',
pwd: '12345',
roles: [{ role: 'readWrite', db: 'SOME_DB' }],
});
db = db.getSiblingDB('SOME_OTHER_DB');
db.createUser({
user: 'some_other_db_user',
pwd: '12345',
roles: [{ role: 'readWrite', db: 'SOME_OTHER_DB' }],
});
db.createCollection('test');