High available OpenVPN server using HAproxy and keepalived

Hi, I have two ubuntu 16.04 server. On the first server I have installed OpenVPN and easy-rsa. I have configured HA using HAProxy and keepalived. now I want to install openvpn on the second server too. So if the first one goes down that can handle my client. So my question is, how should I configure the second server to authenticate my existing client? can I use same CA. If then how? If not then how to embed the keys in the single ovpn file. thanks