ps看haproxy用的就是 /etc/haproxy/haproxy.cfg， /etc/sysconfig/haproxy 是空的，
root 38226 1 0 Jul12 ? 00:00:00 /usr/sbin/haproxy-systemd-wrapper -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid
pirate 38227 38226 0 Jul12 ? 00:00:00 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -Ds
pirate 38228 38227 1 Jul12 ? 00:18:51 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -Ds
cat /etc/sysconfig/haproxy
# Add extra options to the haproxy daemon here. This can be useful for
# specifying multiple configuration files with multiple -f options.
# See haproxy(1) for a complete list of options.
OPTIONS=""