You may add any number of public cloud providers (using API keys or tokens) to your Nova organization. This allows Nova to deploy into your cloud, as well as read information about backends (your virtual machines).
This lets you configure your Nova ADCs to automatically send traffic to matching tags, or AMI IDs on the cloud. Aside from making management easier, it also makes to easy to utilize services like AutoScaling.
AWS backends currently support service discovery on EC2 Instances by AMI ID and Tag.
Visit Security Credentials and select "Access Keys (access key ID and secret access key".
Click "Create New Access Key" and take the Key ID and Secret Key to use when adding the cloud in Nova.
Also make sure to select the right AWS Region for your Instances. You can add multiple AWS accounts if needed with Nova.
Digital Ocean backends currently support service discovery on droplets by tag.
Visit API Management and select "Generate New Token".
Take the token to use when adding the cloud in Nova.
You can install Nova on any Linux system, so if you have an unsupported Cloud just run Nova for Linux, or Docker!