Enable Sticky Sessions in HAProxy

blog20220516-01.cfg

frontend mywebapp
  bind :80
  mode http
  default_backend webservers

backend webservers
  mode http
  balance roundrobin
  cookie SERVER insert indirect nocache
  server web1 192.168.56.20:80 check cookie web1
  server web2 192.168.56.21:80 check cookie web2

blog20220516-02.cfg

frontend mywebapp
  bind :80
  mode http
  default_backend webservers

resolvers mydns
  nameserver dns1 192.168.56.30:53
  accepted_payload_size 8192

backend webservers
  mode http
  balance roundrobin
  cookie SERVER insert indirect nocache dynamic
  dynamic-cookie-key mysecretphrase
  server-template web 10 myservice.example.local:80 check resolvers mydns init-addr libc,none

blog20220516-03.cfg

frontend mywebapp
  bind :80
  mode http
  default_backend webservers

peers sticktables
 bind :10000

 # On the next line, 'loadbalancer1' 
 # is the HAProxy server's hostname
 server loadbalancer1
 table sticky-sessions type ip size 1m

backend webservers
  mode http
  balance roundrobin
  stick match src table sticktables/sticky-sessions
  stick store-request src table sticktables/sticky-sessions
  server web1 192.168.56.20:80 check
  server web2 192.168.56.21:80 check