HAProxy and Consul with DNS for Service Discovery

blog20180405-01.sh

consul agent -server -ui -bootstrap-expect=1 -data-dir=/var/lib/consul \
	-node=server -bind=0.0.0.0 -config-dir=/etc/consul.d -client=0.0.0.0 \
	-http-port=80 -domain=consul.itchy.local

blog20180405-02.json

{
  "dns_config": {
    "enable_truncate": true,
    "udp_answer_limit": 100
  }
}

blog20180405-03.json

{
  "service": {
    "ID": "consul-server",
    "Name": "gui",
    "Address": "dashboard.consul.itchy.local",
    "Port": 80,
    "check": {
      "http": "http://dashboard.consul.itchy.local",
      "interval": "10s",
      "timeout": "1s"
     }
   }
}

blog20180405-04.sh

consul agent -data-dir=/var/lib/consul -node=$HOSTNAME -node-id=$(uuidgen) \
	-bind=0.0.0.0 -config-dir=/etc/consul.d \
	-retry-join <IP addr or hostname of consul agent server>

blog20180405-05.sh

consul-template -template="/haproxy.conf.tmpl:/haproxy.conf:/haproxy_reload.sh" -log-level=debug

blog20180405-06.cfg

resolvers consul
  nameserver consul 127.0.0.1:8600
  accepted_payload_size 8192

blog20180405-07.cfg

{{range services}}{{$servicename := .Name}}{{$nbsrvkeyname := printf "service/haproxy/backend/%s/nbsrv" $servicename}}
backend b_{{$servicename}}.{{key "service/haproxy/domainname"}}
  server-template {{$servicename}} {{keyOrDefault $nbsrvkeyname "10"}} _{{$servicename}}._tcp.service.consul resolvers consul resolve-prefer ipv4 check
{{end}}

blog20180405-08.sh

consul agent -data-dir=/var/lib/consul -node=$HOSTNAME -node-id=$(uuidgen) \
	-bind=0.0.0.0 -config-dir=/etc/consul.d \
	-retry-join <IP addr or hostname of consul agent server>

blog20180405-09.json

{
  "service": {
    "ID": "<your server hostname>",
    "Name": "<the name of the service delivered by this server>",
    "Address": "<local IP address where the service is available>",
    "Port": 80,
    "check": {
      "http": "http://<local IP address where the service is available>:80",
      "interval": "10s",
      "timeout": "1s"
     }
   }
}

blog20180405-10.cfg

use_backend b_%[req.hdr(Host),lower,word(1,:)]

blog20180405-11.cfg

{{range services}}{{$servicename := .Name}}
backend b_{{$servicename}}.{{key "service/haproxy/domainname"}}
[...]
{{end}}

thank you nice tutorial