HaProxy

This is not a tutorial of how haproxy works, this is just some notes on a config i did, and some of the options i used that made it stable for what i needed.

In the example bellow you will find a acceptable cipher, how to add a cookie sessions on HA, SSL offloading, xforward's, ha stats, good timeout vaules, and a httpchk.

global
        log 127.0.0.1 local0 warning
        maxconn 10000
        user haproxy
        group haproxy
        daemon
        spread-checks 5
        tune.ssl.default-dh-param 2048
        ssl-default-bind-ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA

defaults
        log     global
        option  dontlognull
        retries 3
        option redispatch
        maxconn 10000
        mode http
        option dontlognull
        option httpclose
        option httpchk
        timeout connect 5000ms
        timeout client 150000ms
        timeout server 30000ms
        timeout check 1000
        
listen  lb_stats
        bind    {PUBLIC IP}:80
        balance roundrobin
        server  lb1 127.0.0.1:80
        stats   uri /
        stats   realm "HAProxy Stats"
        stats   auth admin:FsoqyNpJAYuD

frontend frontend_{PUBLIC IP}_https
       mode 		   tcp
       bind            {PUBLIC IP}:443 ssl crt /etc/haproxy/ssl/domain.com.pem no-sslv3
       reqadd X-Forwarded-Proto:\ https
       http-request add-header X-CLIENT-IP %[src]
       option          forwardfor
       default_backend backend_cluster_http_web1_web2

frontend frontend_{PUBLIC IP}_http
       bind            {PUBLIC IP}:80
       reqadd X-Forwarded-Proto:\ https
       http-request add-header X-CLIENT-IP %[src]
       option          forwardfor
       default_backend backend_cluster_http_web1_web2

frontend frontend_www_custom
       bind            {PUBLIC IP}:666
       option          forwardfor
       default_backend backend_cluster_http_web1_web2

 backend backend_cluster_http_web1_web2
        option httpchk HEAD /
        server  web1 10.1.2.100:80 weight 1 check cookie web1 inter 1000 rise 5 fall 1
        server  web2 10.1.2.101:80 weight 1 check cookie web2 inter 1000 rise 5 fall 1

Enable xforward on httpd.conf on the web servers

LogFormat "%{X-Forwarded-For}i %h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\ " combine
LogFormat "%{X-Forwarded-For}i %h %l %u %t \"%r\" %s %b \"%{Referer}i\" \"%{User-agent}i\"" combined-forwarded

It is also possible to use the session cookie provided by the backend server.

backend www
        balance roundrobin
        mode http
        cookie PHPSESSID prefix indirect nocache
        server web1 10.1.2.100:80 check cookie web1
        server web2 10.1.2.101:80 check cookie web2

In this example we will intercept the PHP session cookie and add / remove the reference of the backend server.

The prefix keyword allows you to reuse an application cookie and prefix the server identifier,
then delete it in the following queries.

Default name of cookies by type of feeder backend:
Java : JSESSIONID
ASP.Net : ASP.NET_SessionId
ASP : ASPSESSIONID
PHP : PHPSESSID

Active/Passive config

backend backend_web1_primary
        option httpchk HEAD /
        server  web1 10.1.2.100:80 check
        server  web2 10.1.2.101:80 check backup

backend backend_web2_primary
        option httpchk HEAD /
        server  web2 10.1.2.100:80 check
        server  web1 10.1.2.101:80 check backup
Test config file:
haproxy -c -V -f /etc/haproxy/haproxy.cfg

Hapee Check syntax

Hapee VRRP

# /etc/hapee-1.7/hapee-vrrp.cfg

vrrp_script chk_hapee {
    script "pidof hapee-lb"
    interval 2
}

vrrp_instance vrrp_1 {
  interface eth0             
  virtual_router_id 51         
  priority 101                 
  virtual_ipaddress_excluded {
          eth0          
          eth1          
  }
  track_interface {
          eth0 weight -2       
          eth1 weight -2
  }
  track_script {
          chk_hapee
  }
}

vrrp_instance vrrp_2 {
  interface eth1       
  virtual_router_id 51       
  priority 101                 
  virtual_ipaddress_excluded {
          X.X.X.X
  }
  track_interface {
          eth0 weight -2       
          eth1 weight -2
  }
  track_script {
          chk_hapee
  }
}

Doc

https://cbonte.github.io/haproxy-dconv/