MongoDB - Configure an instance to accept incoming connections – Support Guides

Learn how to configure your MongoDB instance to accept incoming connections.

Cloud Databases allow you to focus on building and deploying cloud applications while OVHcloud takes care of the database infrastructure and maintenance in operational conditions.

Requirements

A Public Cloud project in your OVHcloud account
Access to the OVHcloud Control Panel
A MongoDB database running on your OVHcloud Cloud Databases (this guide can help you to meet this requirement)

Instructions

Configure your MongoDB instance to accept incoming connections

Before making a connection, we must verify that our MongoDB instance is correctly configured.

Step 1: Verify your user roles and password

Select the Users tab. Verify that you have a user with sufficient rights and a configured password. If you don't remember the user's password, you can either create a new user or regenerate the password of an existing user. Be careful! By doing so, you will need to update all the places where you already use this user/password pair.

To create a new user, click + Add user.

We provide official MongoDB built-in roles. Please read the official MongoDB documentation to select the right roles for your use case.

In our example, we will create a new user called foo with the role userAdmin on the bar database and the role readWriteAnyDatabase on any database (admin).

Click Create User.

Once created or updated, note the password. After a few seconds, check to verify the user has a "Ready" status in the OVHcloud Control Panel.

Step 2: Authorize incoming connections from the MongoDB client

In this step, select the Configuration tab, add the IP(s) you wish to authorize, and click the add + button. By default, a Cloud Database does not accept any form of connection from the outside world. This way, we can help prevent intrusive connection attempts.

Select Save changes when you are finished.

If you want to allow any connections from the outside, you can enter the IP 0.0.0.0/0. Please use it carefully. Every IP will be authorized.

Get your connection information (URI)

Select the Dashboard tab. In the Connection information section, copy the Service URI.

You can specify the MongoDB connection string using either:

Service -> mongoDB for the Standard Connection String format (soon deprecated).
Service -> mongodbSrv for the DNS Seed List Connection String format.

MongoDB 3.6 introduced the concept of a seed list that is specified using DNS records, specifically SRV and TXT records. This allows a client to connect to a replica set even if one of the nodes that the client specifies is unavailable.
The use of SRV records eliminates the requirement for every client to pass in a complete set of state information for the cluster. Instead, a single SRV record identifies all the nodes associated with the cluster (and their port numbers) and an associated TXT record defines the options for the URI.
Learn more here.

mongodb

It should be similar to this when you have a single node:

mongodb://<username>:<password>@<hostname>/admin?tls=true

And like this when you have a MongoDB cluster with multiple nodes, called a replica set:

mongodb://<username>:<password>@<hostname node1>,<hostname node 2>,<hostname node 3>/admin?replicaSet=replicaset&tls=true

mongodbSrv

It should be similar to this:

mongodb+srv://<username>:<password>@mongodb-xxxxxxxx-xxxxxxxxx.database.cloud.ovh.us/admin?replicaSet=replicaSet=replicaset&tls=true

DNS Seed List Connection Format

Introduced since MongoDB 3.6, this new connection string URI format brings convenience and ease.

Instead of listing all the hosts one by one, MongoDB introduced the concept of DNS-based lists. This method is recommended for drivers > 3.6.

Using DNS to construct the list of available servers allows more flexibility in deployment and the ability to modify the hosts without reconfiguring clients.

Without the SRV record, configuration clients must list several nodes in their connection string.

The use of SRV records eliminates the requirement for clients to pass in a complete set of state information for the cluster. Instead, a single SRV record identifies all the nodes associated with the cluster.

The DNS seed list connection string has the following format:

mongodb+srv://<username>:<password>@server.example.com/[/[defaultauthdb][?options]]

As an example, it may look like this with Public Cloud Databases, even with three nodes:

mongodb+srv://<username>:<password>@mongodb-d2a6c535-o099ad5c9.database.cloud.ovh.us/admin?replicaSet=replicaset&tls=true

The corresponding DNS configuration (SRV records) is specified at the instantiation of the MongoDB service and might resemble:

Record                                                          TTL  Class    Priority Weight Port  Target
_mongodb._tcp.mongodb-d2a6c535-o099ad5c9.database.cloud.ovh.us. 1440 IN SRV   0        5      27017 node1-2d57ab70d2a6c535.database.cloud.ovh.us.
_mongodb._tcp.mongodb-d2a6c535-o099ad5c9.database.cloud.ovh.us. 1440 IN SRV   0        5      27017 node2-2d57ab70d2a6c535.database.cloud.ovh.us.
_mongodb._tcp.mongodb-708c0af6-o1b33fa01.database.cloud.ovh.us. 1440 IN SRV   0        5      27017 node3-2d57ab70d2a6c535.database.cloud.ovh.us.

Select the Users tab to get the username or reset a user password (more options ..., then Reset password).

Go further

Visit the GitHub examples repository to find out how to connect to your database with several languages.

For more information and tutorials, please see our other Managed Databases & Analytics or Platform as a Service guides. You can also explore the guides for other OVHcloud products and services.

If you need training or technical assistance to implement our solutions, contact your sales representative or click on this link to get a quote and ask our Professional Services experts for a custom analysis of your project.