Configure Haproxy as a load balancer for Openshift 4.16

I set up an OpenShift 4.16 cluster using UPI on top of VMware. The cluster has 3 Masters, 3 Worker Nodes, and 3 InfraNodes. The infra nodes were necessary to install IBM Storage Fusion.

After the setup, I needed to create a load balancer in front of the OpenShift cluster. There are several options, and one of them is HAProxy.

I just installed an RHEL 9 server, added 3 ips to the network card and setup the haproxy.

Prerequisites

• A system running RHEL 9
• Root or sudo privileges
• A basic understanding of networking and load balancing

Step 1: Install HAProxy

First, update your system packages:

sudo dnf update -y

Then, install HAProxy using the package manager:

sudo dnf install haproxy -y

Verify the installation:

haproxy -v

Step 2: Configure HAProxy

The main configuration file for HAProxy is located at /etc/haproxy/haproxy.cfg. Open the file in a text editor:

sudo nano /etc/haproxy/haproxy.cfg

The configuration bellow was used for my cluster. Change the IP adresses to match

#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
    # to have these messages end up in /var/log/haproxy.log you will
    # need to:
    #
    # 1) configure syslog to accept network log events.  This is done
    #    by adding the '-r' option to the SYSLOGD_OPTIONS in
    #    /etc/sysconfig/syslog
    #
    # 2) configure local2 events to go to the /var/log/haproxy.log
    #   file. A line like the following can be added to
    #   /etc/sysconfig/syslog
    #
    #    local2.*                       /var/log/haproxy.log
    #
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats

    # utilize system-wide crypto-policies
    #ssl-default-bind-ciphers PROFILE=SYSTEM
    #ssl-default-server-ciphers PROFILE=SYSTEM

#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
    mode                    tcp
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000

#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------

frontend api
    bind 192.168.252.171:6443
    default_backend controlplaneapi

frontend apiinternal
    bind 192.168.252.171:22623
    bind 192.168.252.171:22624
    default_backend controlplaneapiinternal

frontend secure
    bind 192.168.252.170:443
    default_backend secure

frontend insecure
    bind 192.168.252.170:80
    default_backend insecure

#---------------------------------------------------------------------
# static backend
#---------------------------------------------------------------------

backend controlplaneapi
    balance source
    server master-01  192.168.252.5:6443 check
    server master-02  192.168.252.6:6443 check
    server master-03  192.168.252.7:6443 check


backend controlplaneapiinternal
    balance source
    server master-01  192.168.252.5:22623 check
    server master-02  192.168.252.6:22623 check
    server master-03  192.168.252.7:22623 check
    server master-01  192.168.252.5:22624 check
    server master-02  192.168.252.6:22624 check
    server master-03  192.168.252.7:22624 check

backend secure
    balance source
    server worker-01  192.168.252.8:443 check
    server worker-02  192.168.252.9:443 check
    server worker-03  192.168.252.10:443 check
    server  worker-04   192.168.252.11:443 check
    server  worker-05   192.168.252.12:443 check
    server  worker-06   192.168.252.13:443 check

backend insecure
    balance roundrobin
    server worker-01  192.168.252.8:80 check
    server worker-02  192.168.252.9:80 check
    server worker-03  192.168.252.10:80 check
    server worker-04   192.168.252.11:80 check
    server worker-05   192.168.252.12:80 check
    server worker-06  192.168.252.13:80 check