Automatically checks certs for all Azure Application Gateways.
To get started, create an .env file copied from .env.example.
If needed, you can generate an Azure service principal with the following command:
az login
az ad sp create-for-rbac --name ServicePrincipalName --skip-assignment true
You can use the values provided in your .env file, and then assign the service principal
to all appropriate Application Gateways.