Should you use Let's Encrypt for internal hostnames?

We have an internal certificate authority for internal domains at my job. We add the root CA certificate to each desktop or server through an endpoint agent that runs on every machine. That agent is used for monitoring, provisioning users, and even running arbitrary commands.

The article mentions BYOD (bring your own device) but we don't allow personal devices to connect to internal services, so this isn't an issue for us.

You can use something like EasyRSA to set up an internal certificate authority and generate server certificates signed by that certificate authority. I started using plain old OpenSSL for generating certificates, which EasyRSA uses under the hood, but I would have liked to start by using EasyRSA in the first place.

By the way, EasyRSA still isn't that easy, but it's better than using OpenSSL directly.