Syslog support
--------------
Upstream recommends using syslog over UDP to log from HAProxy processes, as
this allows seamless logging from chroot'ed processes without access to
/dev/log. However, many syslog implementations do not enable UDP syslog by
default.

The default HAProxy configuration in Debian uses /dev/log for logging and
ships an rsyslog snippet that creates /dev/log in HAProxy's chroot and logs all
HAProxy messages to /var/log/haproxy.log. To take advantage of this, you must
restart rsyslog after installing this package. For other syslog daemons you
will have to take manual measures to enable UDP logging or create /dev/log
under HAProxy's chroot:
a. For sysklogd, add SYSLOG="-a /var/lib/haproxy/dev/log" to
   /etc/default/syslog.
b. For inetutils-syslogd, add SYSLOGD_OPTS="-a /var/lib/haproxy/dev/log" to
   /etc/default/inetutils-syslogd.

Prometheus exporter
-------------------
HAProxy is shipped with a builtin Prometheus exporter. To enable it,
you need to configure the Prometheus endpoint:

    frontend stats
        bind *:8404
        http-request use-service prometheus-exporter if { path /metrics }
        stats enable
        stats uri /stats
        stats refresh 10s
