Created question in FIWARE Q/A platform on 14-08-2023 at 21:08
Please, ANSWER this question AT https://stackoverflow.com/questions/76902281/fiware-iot-agent-json-connection-to-mongodb-with-authentication

Question:
Fiware IoT Agent JSON connection to MongoDB with authentication

Description:
I'm trying to configure the Fiware IOT Agent Json connection to MongoDB with authentication, but I always get the Authentication Failed error.
I'm running the services via docker-compose, and in the Fiware IOT Agent JSON I have the environment variables IOTA_MONGO_USER and IOTA_MONGO_PASSWORD defined, which correspond to the mongodb username and password.
Here I put some parts of my docker-compose:
iot-agent:
image: fiware/iotagent-json:latest
hostname: iot-agent
container_name: fiware-iot-agent
depends_on:

• mongo-db
  networks:
• fiware
  ports:
• "4041:4041"
• "7896:7896"
  environment:
• IOTA_MONGO_HOST=mongo-db
• IOTA_MONGO_PORT=$ {MONGO_DB_PORT}
  - IOTA_MONGO_USER=${MONGO_USER}
  - IOTA_MONGO_PASSWORD=${MONGO_PWD}
  - IOTA_MONGO_DB=iotagentul
  mongo-db:
  image: mongo:${MONGO_DB_VERSION}
  hostname: mongo-db
  container_name: db-mongo
  expose:
  - "${MONGO_DB_PORT}

  "
  ports:

• "$ {MONGO_DB_PORT}:${MONGO_DB_PORT}

  " # localhost:27017
  networks:

• fiware
  volumes:
• ./volumes/mongo-db/db:/data/db
  environment:
• MONGO_INITDB_ROOT_USERNAME=$ {MONGO_USER}
• MONGO_INITDB_ROOT_PASSWORD=$ {MONGO_PWD}

The error log is this:
(Note: the user and password in the fields below appears fine, I removed it from the post for security)

subsrv=n/a | msg=Attempting to connect to MongoDB instance with url "mongodb://mongo-db:27017/iotagentul" and options {"auth":{"user":"","password":""}}. Attempt 1 | comp=IoTAgent
(node:1) [MONGODB DRIVER] Warning: Current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option

to the MongoClient constructor.
(Use node --trace-warnings ... to show where the warning was created)
(node:1) [MONGODB DRIVER] Warning: Warning: no saslprep library specified. Passwords will not be sanitized

time=2023-08-14T21:12:11.543Z | lvl=ERROR | corr=9ad5f04f-8b95-4292-837e-54c57de0461d | trans=9ad5f04f-8b95-4292-837e-54c57de0461d | op=IoTAgentNGSI.DbConn | from=n/a | srv=n/a | subsrv=n/a | msg=MONGODB-001: Error trying to connect to MongoDB: MongoNetworkError: failed to connect to server [mongo-db:27017] on first connect [MongoError: Authentication failed.
at Connection.messageHandler (/opt/iotagent-json/node_modules/mongodb/lib/core/connection/connection.js:364:19)
at Connection.emit (node:events:513:28)
at Connection.emit (node:domain:552:15)
at processMessage (/opt/iotagent-json/node_modules/mongodb/lib/core/connection/connection.js:456:10)
at Socket. (/opt/iotagent-json/node_modules/mongodb/lib/core/connection/connection.js:625:15)
at Socket.emit (node:events:513:28)
at Socket.emit (node:domain:552:15)
at addChunk (node:internal/streams/readable:315:12)
at readableAddChunk (node:internal/streams/readable:289:9)
at Socket.Readable.push (node:internal/streams/readable:228:10)
at TCP.onStreamRead (node:internal/stream_base_commons:190:23)
at TCP.callbackTrampoline (node:internal/async_hooks:130:17) {
ok: 0,
code: 18,
codeName: 'AuthenticationFailed'
}]

Does anyone know what could be going wrong?
Thanks