docker下的consul集群策略

约定不等于承诺〃 2021-12-05 19:43 264阅读 0赞

最近在弄微服务项目的docker化，为了实现consul的高可用，考虑在每一个docker容器中都集成一个consul-client，通过统一注册到外部集群的服务器上的consul-server上，实现服务的高可用，及单个consul挂掉不会导致全部服务的宕机。

这里简单演示下实现步骤，这里我们在宿主机中搭建consul-server，在每个docker中搭建consul-client。

# consul-server #

新建文件夹`mkdir -pv /etc/consul.d/ && mkdir -pv /data/consul/ && mkdir -pv /data/consul/shell`

编写server.json文件`vim /etc/consul.d/server.json`

{ 
      "datacenter": "dc1",
      "data_dir": "/data/consul",
      "log_level": "INFO",
      "node_name": "consul-server01",
      "server": true,
      "bootstrap_expect": 1,
      "bind_addr": "10.xx.xx.90",
      "client_addr": "10.xx.xx.90",
      "ui":true,
      "retry_join": ["10.xx.xx.90","10.xx.xx.91"],
      "retry_interval": "10s",
      "enable_debug": false,
      "rejoin_after_leave": true,
      "start_join": ["10.xx.xx.90","10.xx.xx.91"],
      "enable_syslog": true,
      "syslog_facility": "local0"
    }

这里ip脱敏了，大家应该都能看出来。。。另外这里配置的是两台server机的写法表述server集群的写法，本文其实只配了一台90，去掉后面的91即可。

# consul-client #

首先构建Dockerfile文件，同级目录下准备好解压好的consul。文件目录：

[root@localhost consul-client]# ll
    total 104404
    -rw-r--r-- 1 root root       269 Jul 17 14:46 Dockerfile
    -rwxr-xr-x 1 root root 106903403 Jul 17 14:43 consul

Dockerfile内容：

FROM centos7.3-jdk8:1.0.0  # 项目运行的基础环境
    MAINTAINER herobin1995@163.com
    LABEL Description="This is a consul-client:test image " Vendor="Tisp base project" Version="V1.0.0"
    USER root
    WORKDIR /project
    COPY consul /project/

构建镜像：`docker build -t consul-client:test -f Dockerfile .`  
启动容器：`docker run -ti -p 8501:8500 consul-client:test`

进入容器中后，获取本机ip写入环境变量。

export localip=$(ifconfig | grep 'inet'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $2}' )
    source /etc/profile

编写并执行consul-client脚本自动生成写入client.json配置文件，这里脚本方式写入是为了能够动态获取上面写入环境变量的本机ip。  
`vi consul-client.sh`

mkdir -pv /etc/consul.d/
    mkdir -pv /data/consul/
    mkdir -pv /data/consul/shell
    cd /etc/consul.d
    echo "{" > client.json
    echo "\"data_dir\": \"/data/consul\"," >> client.json
    echo "\"enable_script_checks\": true," >> client.json
    echo "\"bind_addr\": \"$localip\"," >> client.json
    echo "\"client_addr\": \"$localip\"," >> client.json
    echo "\"retry_join\": [\"10.xx.xx.90\"]," >> client.json
    echo "\"retry_interval\": \"30s\"," >> client.json
    echo "\"rejoin_after_leave\": true," >> client.json
    echo "\"start_join\": [\"10.xx.xx.90\"] ," >> client.json
    echo "\"node_name\": \"node1\"" >> client.json
    echo "}" >> client.json

执行脚本生成consul-client的json文件：`sh consul-client.sh`，可以通过命令查看内容`cat /etc/consul.d/client.json`.

[root@c0b549757da0 project]# cat /etc/consul.d/client.json 
    { 
    "data_dir": "/data/consul",
    "enable_script_checks": true,
    "bind_addr": 172.17.0.2,
    "retry_join": ["10.xx.xx.90"],
    "retry_interval": "30s",
    "rejoin_after_leave": true,
    "start_join": ["10.xx.xx.90"] ,
    "node_name": "node1"
    }

# 验证 #

*  启动consul-server：在宿主机启动server节点`nohup consul agent -config-dir=/etc/consul.d > /data/consul/consul.log &`
 *  启动consul-client：在容器汇总启动client节点`nohup ./consul agent -config-dir=/etc/consul.d > /data/consul/consul.log &`  
    **注意**这里要加上**-client-dev**。`nohup ./consul agent -dev -client $localip -config-dir=/etc/consul.d > /data/consul/consul.log &`
 *  查看consul成员：`consul members -http-addr='10.xx.xx.90:8500'`
    
        [root@e992cc5dcae5 project]# ./consul members -http-addr='10.xx.xx.90:8500'
        Node             Address            Status  Type    Build  Protocol  DC   Segment
        consul-server01  10.xx.xx.90:8301  alive   server  1.2.2  2         dc1  <all>
        node1            172.17.0.2:8301    alive   client  1.5.2  2         dc1  <default>
 *  访问consulserver的web页面：`http://10.xx.xx.90:8500/ui/`