The haproxy systemd service file is not pulling in options from the sysconfig file. The haproxy package installs file /etc/sysconfig/haproxy which contains an empty list of options that a user can define as needed that will then used by the systemd service file:


% 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=""


However the service file is not using the OPTIONS:


%cat /usr/lib/systemd/system/haproxy.service 
[Unit]
Description=HAProxy Load Balancer
After=network.target

[Service]
Environment="CONFIG=/etc/haproxy/haproxy.cfg" "PIDFILE=/run/haproxy.pid"
ExecStartPre=/usr/sbin/haproxy -f $CONFIG -c -q
ExecStart=/usr/sbin/haproxy -Ws -f $CONFIG -p $PIDFILE
ExecReload=/usr/sbin/haproxy -f $CONFIG -c -q
ExecReload=/bin/kill -USR2 $MAINPID
SuccessExitStatus=143
KillMode=mixed
Type=notify

[Install]
WantedBy=multi-user.target


For comparison, haproxy in RHSCL does correctly use the OPTIONS:


% cat haproxy.service 
[Unit]
Description=HAProxy Load Balancer
After=network.target

[Service]
Environment="CONFIG=/etc/haproxy/haproxy.cfg" "PIDFILE=/run/haproxy.pid"
EnvironmentFile=/etc/sysconfig/haproxy
ExecStartPre=/usr/sbin/haproxy -f $CONFIG -c -q $OPTIONS
ExecStart=/usr/sbin/haproxy -Ws -f $CONFIG -p $PIDFILE $OPTIONS
ExecReload=/usr/sbin/haproxy -f $CONFIG -c -q $OPTIONS
ExecReload=/bin/kill -USR2 $MAINPID
KillMode=mixed
Type=notify

[Install]
WantedBy=multi-user.target