AWS EC2 connection failing, could not find user

MongoDB Atlas
,
#1

I’m trying to connect to atlas cluster from an ec2, but either if I try by code (nodejs) or by cli, I get this error:

MongoError: Could not find user "arn:aws:sts::030800513199:assumed-role/designspecs-staging-design-Api-1U4X5W-InstanceRole-1TTX7XR8B1D7N/*" for db "$external"

It is the right role, the problem is that the registered arn on atlas is the one of the role:
arn:aws:iam::030800513199:role/designspecs-staging-design-Api-1U4X5W-InstanceRole-1TTX7XR8B1D7N

And I cannot register the STS one because atlas says it is an invalid arn.

This is the instance role which mongodb should retrive. If I put in a .env file the keys of a iam user and I make that user a database user for Atlas it works (because the retrived arn is correct).

Am I missing something? How can I connect the EC2 to atlas without using passwords?

#2

For completeness I should say that I am not assuming any role explicitly, this is the connection code:

const remoteDb = `${MONGO_DATABASE_HOST}/${MONGO_DATABASE_NAME}?authSource=%24external&authMechanism=MONGODB-AWS&retryWrites=true&w=majority`;
const localDb = `mongodb://${MONGO_DATABASE_USERNAME}:${MONGO_DATABASE_PASSWORD}@${MONGO_DATABASE_HOST}:27017/${MONGO_INITDB_DATABASE}`;

const mongoURL = process.env.END !== 'dev' ? remoteDb : localDb;

const connect = () =>
	mongoose
		.connect(mongoURL, config)
		.then(() => {
			console.log('[MongoDB] CONNECTED!');
		})
		.catch(err => {
			console.error(err);
			console.error(`[MongoDB] ERRROR: NON CONNECTED! -> ${mongoURL}`);
		});

connect();

module.exports = mongoose.connection;

Where MONGO_DATABASE_HOST is the srv connection string when I am on remote

#3

I found that it was a problem given by the atals user scope. The user used to exist, the problem was that he didn’t have the right to see the specific cluster I wanted to connect to. This mistake was given by the fact that I used the aws quickstart template to deploy mongodb, which limits the scope of the user to some resources, removing that part now it works.

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#4

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#7

Hi @Emanuele_Caruso - Welcome to the community and thank you for posting the solution!

This mistake was given by the fact that I used the aws quickstart template to deploy mongodb, which limits the scope of the user to some resources, removing that part now it works.

To see if any improvements could be made, could you provide more information regarding the Quick Start guide you have followed? Would it be the MongoDB Atlas on the AWS Cloud Quick Start Reference Deployment? If so, could you also advise the template used?

but either if I try by code (nodejs) or by cli

Additionally, for testing purposes, does the “cli” mentioned above refer to mongo shell?

Look forwrad to hearing from you.

Regards,
Jason

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