Docker mongo and mongo-express connection issue

Question

When I'm trying to connect to mongo-express I'm getting a connection issue, kind of error

version: "3"
services:
  mongodb:
    image: mongo
    ports:
      - "27017:27017"
    environment:
      - MONGO_INITDB_ROOT_USERNAME=anirban
      - MONGO_INITDB_ROOT_PASSWORD=mypass
  mongo-express:
    image: mongo-express
    ports: 
      - "8081:8081"
    restart: always
    environment:
      - ME_CONFIG_MONGODB_SERVER=mongodb
      - ME_CONFIG_MONGODB_ADMINUSERNAME=anirban
      - ME_CONFIG_MONGODB_ADMINPASSWORD=mypass

The above is my docker-compose.yaml

so after this, in my docker desktop > mongo-express process I'm getting this page, Running container

Then after 1 minute approx, I'm getting the localhost:8081 up and running in my browser,

2024-01-21 13:15:53 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:15:53 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:15:59 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:15:59 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:05 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:05 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:15:48 Waiting for mongo:27017...
2024-01-21 13:15:54 Sun Jan 21 07:45:54 UTC 2024 retrying to connect to mongo:27017 (2/10)
2024-01-21 13:16:00 Sun Jan 21 07:46:00 UTC 2024 retrying to connect to mongo:27017 (3/10)
2024-01-21 13:16:06 Sun Jan 21 07:46:06 UTC 2024 retrying to connect to mongo:27017 (4/10)
2024-01-21 13:16:11 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:11 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:12 Sun Jan 21 07:46:12 UTC 2024 retrying to connect to mongo:27017 (5/10)
2024-01-21 13:16:17 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:17 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:18 Sun Jan 21 07:46:18 UTC 2024 retrying to connect to mongo:27017 (6/10)
2024-01-21 13:16:23 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:23 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:24 Sun Jan 21 07:46:24 UTC 2024 retrying to connect to mongo:27017 (7/10)
2024-01-21 13:16:29 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:29 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:30 Sun Jan 21 07:46:30 UTC 2024 retrying to connect to mongo:27017 (8/10)
2024-01-21 13:16:35 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:35 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:36 Sun Jan 21 07:46:36 UTC 2024 retrying to connect to mongo:27017 (9/10)
2024-01-21 13:16:41 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:41 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:42 Sun Jan 21 07:46:42 UTC 2024 retrying to connect to mongo:27017 (10/10)
2024-01-21 13:16:47 /docker-entrypoint.sh: line 15: mongo: Try again
2024-01-21 13:16:47 /docker-entrypoint.sh: line 15: /dev/tcp/mongo/27017: Invalid argument
2024-01-21 13:16:48 No custom config.js found, loading config.default.js
2024-01-21 13:16:48 Welcome to mongo-express 1.0.2
2024-01-21 13:16:48 ------------------------
2024-01-21 13:16:48 
2024-01-21 13:16:48 
2024-01-21 13:16:49 Server is open to allow connections from anyone (0.0.0.0)
2024-01-21 13:16:49 basicAuth credentials are "admin:pass", it is recommended you change this in your config.js!
2024-01-21 13:16:49 Mongo Express server listening at http://0.0.0.0:8081

Is it normal that it's taking much time to load, or there's some issue because there are many invalid arguments in the Running Container picture.

I've been getting this since the beginning, I just started Docker

Answer 1

Is it like your mongo container was not started yet and mongo express already trying to connect it? Then you should try to add dependency like this:

mongo-express:
 ...
 depends_on:
      - mongodb