Instruction from https://serverfault.com/questions/1002144/install-haproxy-2-on-centos-7

Steps

Choose the haproxy branch

The 1st step defines the branch you are going to install, If you want latest of 2.0 just modify the URL to the branch you want, you'll have to repeat that change in every step you see an URL:

LATEST_HAPROXY=$(wget -qO-  http://www.haproxy.org/download/2.4/src/ | egrep -o "haproxy-2\.[0-9]+\.[0-9]+" | head -1)

Download and install the package:

cd /usr/src/
wget http://www.haproxy.org/download/2.4/src/${LATEST_HAPROXY}.tar.gz
tar xzvf ${LATEST_HAPROXY}.tar.gz
yum install gcc-c++ openssl-devel pcre-static pcre-devel systemd-devel -y
cd /usr/src/${LATEST_HAPROXY}
make TARGET=linux-glibc USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1 USE_CRYPT_H=1 USE_LIBCRYPT=1 USE_SYSTEMD=1  USE_PROMEX=1    
mkdir /etc/haproxy
make install

Create a systemd service /usr/lib/systemd/system/haproxy.service

cat > /usr/lib/systemd/system/haproxy.service << 'EOL'

[Unit]
Description=HAProxy Load Balancer
After=syslog.target network.target


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


[Install]
WantedBy=multi-user.target
EOL

Create /etc/haproxy/haproxy.cfg

cat > /etc/haproxy/haproxy.cfg << 'EOL'

global
 log /dev/log local0
 log /dev/log local1 notice
 daemon


defaults
 log global
 option dontlognull
 timeout connect 50000
 timeout client  50000
 timeout server  50000


listen ListenName
        bind *:80
        mode tcp
        server YourServer 127.0.0.1:80
EOL

Restart HAProxy and verify bash

systemctl start haproxy
systemctl status haproxy

Install BIRD Daemon

https://skyenet.tech/bird/

Set up HAProxy in External Mode

In general, the instruction is at https://www.haproxy.com/documentation/kubernetes/latest/installation/community/external-mode/.

However, since we've already install calico using Kubespray, we don't need to follow every step. The steps to use are

Install Kubernetes

6. Copy admin.conf to the server, remember to change server address to the actual master node address
7. Create a file named calico-bgp.yaml, remember the asNumber
8. Just follow instruction
9. Just follow instruction

Install Haproxy Ingress Controller