serf-web-load-balancer

original https://github.com/hashicorp/serf/tree/master/demo/web-load-balancer

refs https://github.com/kentaro/serf-hosts

Usage

Load Balancer Node

install command.

export SERF_ROLE=lb
sh ./setup_load_balancer.sh
sh ./setup_serf.sh

stop agent command.

stop serf

start agent command.

start serf

Web Node

require apache or nginx.

install command.

export SERF_ROLE=web
export LB_IP="xxx.xxx.xxx.xxx"
sh ./setup_serf.sh

As a result,

web is now also a member of cluster.
member-join event is occurred.
web is added into /etc/haproxy/haproxy.cfg on lb node.

[root@lb001 ~]# cat /etc/haproxy/haproxy.cfg
global
    daemon
    maxconn 256

defaults
    mode http
    timeout connect 5000ms
    timeout client 50000ms
    timeout server 50000ms

listen stats
    bind *:9999
    mode http
    stats enable
    stats uri /
    stats refresh 2s

listen http-in
    bind *:80
    balance roundrobin
    option http-server-close
    server web001.foo.com 192.168.xxx.xxx check
    server web002.foo.com 192.168.xxx.xxx check

stop agent and leave command.

sudo stop serf

start agent and join command.

sudo start serf
sudo start serf-join

see the members of the Serf cluster

serf members

Web Node Leaves

stop web. Then member-leave event is propagated to lb and the handler script is fired.

sudo stop serf