I recently had to figure out the IP address of my Mongo Atlas services. I needed to whitelist the IP address of the service in order to connect to the database from a VPN subnet router.

I spent far too much time trying to figure this out. It turns out it is actually in their documentation here but I missed it.

In order to get the IP address/range of the service, you can do the following:

1. Find your cluster hostnames from the Mongo Atlas dashboard. They can be found on the Metrics tab of the database. They look something like this: cluster0-shard-00-00-abcde.mongodb.net
2. Preform an nslookup on the hostname. For example: nslookup cluster0-shard-00-00-abcde.mongodb.net. This will return the IP address of the service. Example output Address: 18.200.32.136.
3. If you are looking to allow access from the entire cluster, you would need to perform the above steps on each node in the cluster.

Done!