• 环境准备
  • consul client
  • consul server
  • docker环境
• registrator
• 几个常用API
  • deregister
• consul template
• 附supervisor(centos 6可用该方法)
  • pip install

环境准备

client agent:node1 192.168.0.11 server agent:node2 192.168.0.12

consul client

node1 192.168.0.11

• /etc/default/consul :

   CONSUL_FLAGS="-data-dir=/opt/consul/data -config-dir=/opt/consul/conf -pid-file=/opt/consul/run/consul.pid -client=0.0.0.0 -bind=192.168.0.11 -node=consul-node-1 -retry-join '192.168.0.12'"
  

• /usr/lib/systemd/system/consul.service

  [Unit]
  Description=Consul service discovery agent
  Requires=network-online.target
  After=network-online.target
  [Service]
  User=consul
  Group=consul
  EnvironmentFile=-/etc/default/consul
  Environment=GOMAXPROCS=2
  Restart=on-failure
  ExecStartPre=[ -f "/opt/consul/run/consul.pid" ] && /usr/bin/rm -f /opt/consul/run/consul.pid
  ExecStart=/usr/bin/consul agent $CONSUL_FLAGS
  ExecReload=/bin/kill -HUP $MAINPID
  KillSignal=SIGTERM
  TimeoutStopSec=5
  [Install]
  WantedBy=multi-user.target
  

• /usr/bin/consul
• /opt/consul/{data,run,conf}
• useradd consul

consul server

192.168.0.12 node2

• /etc/default/consul

  CONSUL_FLAGS="-server -ui -bootstrap-expect=1 -data-dir=/opt/consul/data -config-dir=/opt/consul/conf -pid-file=/opt/consul/run/consul.pid -client=0.0.0.0 -bind=192.168.0.12 -node=consul-server"
  

• /usr/lib/systemd/system/consul.service

  [Unit]
  Description=Consul service discovery agent
  Requires=network-online.target
  After=network-online.target
  [Service]
  User=consul
  Group=consul
  EnvironmentFile=-/etc/default/consul
  Environment=GOMAXPROCS=2
  Restart=on-failure
  ExecStartPre=[ -f "/opt/consul/run/consul.pid" ] && /usr/bin/rm -f /opt/consul/run/consul.pid
  ExecStart=/usr/bin/consul agent $CONSUL_FLAGS
  ExecReload=/bin/kill -HUP $MAINPID
  KillSignal=SIGTERM
  TimeoutStopSec=5
  [Install]
  WantedBy=multi-user.target
  

• /usr/bin/consul
• /opt/consul/{data,run,conf}
• useradd consul

docker环境

搭建简单web。https://hub.docker.com/r/crccheck/hello-world/

$ docker run -d -P crccheck/hello-world
$ curl localhost:$port  #port为自动暴露的宿主机端口
Hello World

registrator

client端装registator，结合docker API 实现服务自动发现、注册及注销，consul注册地址请注意填写agent地址，请勿直接注册进catalog。https://github.com/kaizamm/registrator

$ docker run -d \
    --name=registrator \
    --net=host \
    --volume=/var/run/docker.sock:/tmp/docker.sock \
    gliderlabs/registrator:latest \
      consul://192.168.0.11:8500

几个常用API

deregister

{
  "Datacenter": "dc1",
  "Node": "foobar"
}
{
  "Datacenter": "dc1",
  "Node": "foobar",
  "CheckID": "service:redis1"
}
{
  "Datacenter": "dc1",
  "Node": "foobar",
  "ServiceID": "redis1"
}

如：

#删除这个该Node的及上面的所有service/heath check/
curl -X PUT -d '{"Datacenter":"dc1","Node":"consul-node-1"}' 172.30.33.4:8500/v1/catalog/deregister

consul template

• download地址: https://releases.hashicorp.com/consul-template/0.19.4/
• github地址：https://github.com/kaizamm/consul-template

consul-template -template "in.tpl:out.txt"   #根据in.tpl的模版文件生成out.txt，consult-template以daemon方式运行
consul-template -template "in.tpl:out.txt" -once   #非daemon方式
consul-template -template "in.tpl:out.conf:service nginx -s reload"  #第三个参数为要执行的动作

根据in.tpl生成out.conf

#in.tpl
upstream hello-world {
  {{ range service "hello-world"}}
  server {{ .Address }}:{{ .Port }}; {{ end }}
}

server {
  listen 8080;
  location /{
    proxy_pass http://hello-world;
  }
}

运行以上consul-template，查看out.conf

upstream hello-world {

  server 192.168.0.12:7777;
  server 192.168.0.12:8888;
}

server {
  listen 8080;
  location /{
    proxy_pass http://hello-world;
  }
}

到此为止，结合consul agent + consul template + consul registrator 就能实现服务发现与自动扩容

附supervisor(centos 6可用该方法)

对于redhat7可以采用systemctl对服务控制，对于centos6,则可以考虑用附supervisor对其进程进行管理 http://supervisord.org/installing.html

pip install

wget https://bootstrap.pypa.io/get-pip.py --no-check-cetificate
python get-pip.py install

如：

#cat /etc/supervisor/django.conf
[program:django]
directory = /usr/local/cmdb ;
command = python manage.py runserver 0.0.0.0:7990 ;
stdout_logfile = /opt/logs/supervisor/django_out.log ;
stderr_logfile = /opt/logs/supervisor/django_err.log ;
autostart = true ;
startsecs = 5 ;
autorestart = true ;
startretries = 3 ;
user = root ;