I've been successful in creating a Virtual Network, adding subnets and security groups to different levels of our infrastructure, and installing OpenVPN on a VM and establishing a connection to it (even giving myself a static IP). Unfortunately, this is where my knowledge ends.
For my client, I'm interested in "pulling" in multiple subnets so I can access our servers (API Gateway management GUI, database server, etc. ) through a VPN connection.
For clients I will add in the future (our support team), I am interested in giving them access to only one azure subnet, which will sequester our back office application. I do not want this endpoint exposed to the public internet and I don't want to manually add everyone's IP Addresses at home, grandma's house, etc. A VPN seems correct.
Things I've Tried
I only somewhat understand how User Defined Routes work in Azure, especially as they relate to my use case.
I have been able to enable IP Forwarding for my VM running OpenVPN.
I've created a dedicated OpenVPN client config file for me.
I'm not using the built-in Point 2 Site Gateway in Azure because it does not support OSX and I would rather not force myself and everyone else to run Parallels.
I've also used this guide to help me along some even though
Firewall !== VPN Server. I'm not quite connecting the dots though.
EDIT: Not sure if this makes a difference, but let's go ahead and assume I'll switch from OpenVPN to OpenVPN Access Server in the near future.