Mongodb replica set with authentication enabled

[milindagashe]

Versions

• NodeJS: 16
• mongodb-memory-server-*: 8.4.2
• mongodb(the binary version):
• mongodb(the js package): 4.5.0
• mongoose: 6.2.10
• system: Windows, Linux

package: mongo-memory-server

What is your question?

I am using below piece of code to create a replica set and it works fine with I am accessing the mongodb from the same server. From the different server, it says connection refused. I understand we have to add authentication to be able to gain access to mongodb from another server. Could you please suggest how to do it? I tried various things, but somehow all my attempts failed.

const replset = await MongoMemoryReplSet.create({
      instanceOpts: [{
        port: 57398
      }],
      replSet: {
        count: 1,
        dbName: 'TestDB'
      }
    })
    const uri = replset.getUri()

[hasezoey]

i think your problem is 1 or 2 of the following 2 options:

• you are not keeping the server alive long enough (the instance that MMS handles will only be alive when the nodejs process did not exit and .stop has not been called)
• if you want to access it from "not the local machine", you will have to bind its ip, which can be easily done in MMS

for replsets:

const replset = await MongoMemoryReplSet.create({
  replSet: {
    ip: "0.0.0.0" // change this ip to something more secure if wanted, see linked documentation for more
  }
});

for single instances:

const instance = await MongoMemoryServer.create({
  instance: {
    ip: "0.0.0.0" // change this ip to something more secure if wanted, see linked documentation for more
  }
});

PS: i will move this issue to a discussion

[milindagashe]

Hello, I checked both above things. Nodejs process which creates replica set does exist while other process tries to access the DB.
I also used '0.0.0.0' as suggested above, but in vain.
To give some more info, I am facing this issue when I am using docker-compose. In docker compose, every service is given a unique IP address which can be accessed only within the network that docker-compose creates by default. In docker-compose config, there are 2 services, one which is responsible for creating a mongo memory server replicaset and the other which is using this replicaset. Both the processes are up and running. After inspecting the logs I found below:
service 1 (which creates db replicaset): IP address: 172.18.0.9
service 2(which consumes the db): IP address: 172.18.0.7
Service 1 is delayed by 20 seconds, so it means it only creates a db replicaset after 20 seconds after it starts. Service 2 starts to connect to the db right after it starts. So I am expecting "no connection" for the first 20 seconds and later Service 2 should establish the connection.
Service 2 logs look like below:
For the first 20 seconds, it says: error: MongooseServerSelectionError: connect ECONNREFUSED 172.18.0.9:57398
Strangely, after 20 seconds (when the db is actually up and running) it says: error: MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:57398

Don't understand why IP address is changing to 127.0.0.1 after db is up and running.

[hasezoey]

Don't understand why IP address is changing to 127.0.0.1 after db is up and running.

i also have no clue, maybe it is just a display error, because i have also observed this behavior in other issues, but still have not found a reason for it

service 1 (which creates db replicaset): IP address: 172.18.0.9
service 2(which consumes the db): IP address: 172.18.0.7

if i remember correctly, you dont need to deal with ip addresses, just use the container names (works like DNS)

in this case if your container name for the db container is service-db, then in the second instead of the IP, but in service-db (like mongodb://service-db:57398)

To give some more info, I am facing this issue when I am using docker-compose

if your "problems" is just about startup then you should be able to use docker-compose config option depends_on which basically only starts the container that this field is on when all containers in the array are in state "running"

---

if it still does not work, maybe check if the wanted port is actually exposed in the docker-compose config (like ports: - 57398:57398)