Configure HAProxy to include host headers for different backends

I'm not sure if the following will work, and can't test right now, but maybe this is still helpful. (I'll have a look again later with some more time):

Solution 1:

backend nodes
    mode http
    balance roundrobin
    option forwardfor
    http-request set-header Host node1.myapp.mycompany.com if { srv_id 1 }
    http-request set-header Host node2.myapp.mycompany.com if { srv_id 2 }
    server web01 node1.myapp.mycompany.com:80
    server web02 node2.myapp.mycompany.com:80

Solution 2:

backend nodes
    mode http
    balance roundrobin
    option forwardfor
    http-send-name-header Host
    server node1.myapp.mycompany.com node1.myapp.mycompany.com:80
    server node1.myapp.mycompany.com node2.myapp.mycompany.com:80