set load-balancing reverse-proxy service foo port '4443'
set load-balancing reverse-proxy service foo rule 10 set backend 'bk01'
set load-balancing reverse-proxy service foo rule 10 url-path end '/local'
set load-balancing reverse-proxy backend bk01 server s1 address '192.0.2.1'
set load-balancing reverse-proxy backend bk01 server s1 port '4443'

cat /run/haproxy/haproxy.cfg


# Frontend
frontend foo
    bind :::4443 v4v6  
    # rule 10


# Backend
backend bk01
    balance roundrobin
    option forwardfor
    http-request set-header X-Forwarded-Port %[dst_port]
    http-request add-header X-Forwarded-Proto https if { ssl_fc }
    server s1 192.0.2.1:4443