Instalar HA Proxy en CentOS 7:

yum -q -y install wget gcc pcre-static pcre-devel

cd /usr/src
wget http://www.haproxy.org/download/1.6/src/haproxy-1.6.11.tar.gz
tar xzf haproxy-1.6.11.tar.gz
cd haproxy-1.6.11
make TARGET=custom CPU=native USE_PCRE=1 USE_LIBCRYPT=1 USE_LINUX_SPLICE=1

make install
cp /usr/local/sbin/haproxy /usr/sbin/

cp examples/haproxy.init /etc/init.d/haproxy
chmod 755 /etc/init.d/haproxy
mkdir -p /etc/haproxy
mkdir -p /run/haproxy
mkdir -p /var/lib/haproxy
touch /var/lib/haproxy/stats
useradd -r haproxy

haproxy -v

service haproxy start
chkconfig haproxy on

Configuración para encapsular Netdata o cualquier otro backend con HAProxy, usuario: myuser password: mypassword

global
    log         127.0.0.1 local2
    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

defaults
    mode        http
    log         global
    option      dontlognull
    option      httpclose
    option      httplog
    option      forwardfor
    option      redispatch
    timeout connect 10000 # default 10 second time out if a backend is not found
    timeout client 300000
    timeout server 300000
    maxconn     60000
    retries     3

userlist netdata_users
    group admin users myuser
    user myuser insecure-password mypassword

frontend http-netdata
        bind *:19998
        default_backend netdata-server
        acl auth_ok http_auth(netdata_users)
        http-request auth unless auth_ok

backend netdata-server
        server serverhttpd 127.0.0.1:19999 maxconn 64