I would like to install the OpenVPN client with the OpenWRT image but the standard way of using the Software selection from the GUI is yielding the following:
Only install openvpn-openssl and luci-app-openvpn packages, skip installing easy rsa package and generate key on a linux computer, then upload them to the router. I have Archer C20 with 8MB flash and openvpn + mwan 3 fits into it.
In addition to what kukulo said about not installing any RSA certificate tools (openssl-util and easyrsa), use openvpn-wolfssl, since the wolfssl library is already present in the default build and won't need to be installed again. Openssl by itself is huge.
I use xca to generate and manage certificates on a PC. It exists for Linux and Windows. If you are only interested in running a VPN client to connect to someone else's service, they will provide you the certificates.
I can't find an "Online" Image Builder. However, I did manage to following this YouTube video to get local build system up and running: https://www.youtube.com/watch?v=m9uWM6QUnpM.
Now, I'm a little confused on how to isolate what packages I need and those I don't. I couldn't find any explicit guidance on how to determine this. So, I figured I would try to determine what's installed on the default OpenWRT firmware distro for my router, but I can't find any explicit guidance on this either.
So, my question is...how do I ensure I have all the packages I actually need vs. those I don't?
I found that site during my initial review of info. Maybe I missed something, but the links for custom stuff for general router use (i.e. non-mesh node) seem dead or unsupported.