I am hosting a couple of web sites on couple Linux boxes and OWA on a Windows box in my office. Currently http is forwarded to Host_W and https is forwarded to Host_M. Host_W serves pages for www.site-m.biz, www.site-d.net, and www.site-f.com while it forwards requests for host_l.site-s.org and www.site-s.org to Host_L. The current structure looks like this:
What I want to do is forward both http and https to Host_W while serving the same three sites and forward https requests for mail.site-m.biz to Host_M and requests for site-s.org to Host_L. The structure would look something like:
I have attached sanitized copies of what I think are the relevant config files.
The port forward is not a problem, simple change on the firewall. Installing Let's Encrypt certificate on both Nginx and Apache2 are heavily documented and a Godaddy certificate for mail.site-m.biz is already installed on Host-M.
What I don't have a handle on is the changes needed on the Apache2 on Host_W. I think it would be just to add something to the site-m.biz.conf like (and something similar to site-l.org.conf):
<VirtualHost *:443> ServerName mail.site-m.biz SSLEngine On SSLProxyEngine On ProxyRequests Off SSLProxyCheckPeerCN off SSLProxyCheckPeerName off SSLProxyCheckPeerExpire off SSLInsecureRenegotiation on SSLProxyVerify none SSLVerifyClient none ProxyPass / https://mail.site-m.biz/ ProxyPassReverse / https://mail.site-m.biz/ <Location "/"> Require all granted </Location></VirtualHost>