consul是什么？

consul概念：

consul是用来做注册中心的他和eureka是一样的注册中心一般都是集群的形式存在
保证高可用 consul像是一个nosql 存储着键值对可以做存储
consul是c/s架构的其客户端负责和用户进行通讯没有实际的意义真正工作的是后端的服务端存储数据也是在服务端存储

环境：

主机	ip
consul-1	192.168.10.20
consul-2	192.168.10.30
consul-3	192.168.10.40
client客户端	192.168.10.10

在第一、二台consul主机和第四台client主机上安装jdk和maven环境
安装jdk

[root@localhost ~]# java -version

openjdk version "1.8.0_102"

OpenJDK Runtime Environment (build 1.8.0_102-b14)

OpenJDK 64-Bit Server VM (build 25.102-b14, mixed mode)

[root@localhost ~]# rm -rf /usr/bin/java #删除原本主机上的Java程序

[root@localhost ~]# java -version

-bash: /usr/bin/java: 没有那个文件或目录

[root@localhost ~]# tar -zxf jdk-8u201-linux-x64.tar.gz

[root@localhost ~]# mv jdk1.8.0_201/ /usr/local/java

添加环境变量（通常情况我们使用第二种方法）

[root@localhost bin]# vim /etc/profile

#末尾添加

export JAVA_HOME=/usr/local/java

export JRE_HOME=/usr/local/java/jre

export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib

export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

[root@localhost bin]# source /etc/profile

[root@localhost bin]# echo $PATH

/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/java/bin:/usr/local/java/jre/bin

[root@localhost bin]# java -version

java version "1.8.0_201"

Java(TM) SE Runtime Environment (build 1.8.0_201-b09)

Java HotSpot(TM) 64-Bit Server VM (build 25.201-b09, mixed mode)

安装maven

[root@localhost ~]# tar -zxf apache-maven-3.6.0-bin.tar.gz

[root@localhost ~]# mv apache-maven-3.6.0 /usr/local/maven

[root@localhost ~]# vim /etc/profile

export PATH=$PATH:/usr/local/maven/bin

[root@localhost ~]# source /etc/profile

[root@localhost ~]# mvn -v

Apache Maven 3.6.0 (97c98ec64a1fdfee7767ce5ffb20918da4f719f3; 2018-10-25T02:41:47+08:00)

Maven home: /usr/local/maven

Java version: 1.8.0_201, vendor: Oracle Corporation, runtime: /usr/local/java/jre

Default locale: zh_CN, platform encoding: UTF-8

OS name: "linux", version: "3.10.0-514.el7.x86_64", arch: "amd64", family: "unix"

安装consul服务（四台都要安）

[root@localhost ~]# unzip consul_1.4.0_linux_amd64.zip -d /usr/bin/

Archive:  consul_1.4.0_linux_amd64.zip

  inflating: /usr/bin/consul

[root@localhost ~]# mkdir -p /opt/consul/{data,config,logs}

参数释义：
data：存放数据的目录
config：存放配置信息的目录
logs：存放日志

consul没有配置文件，所以直接通过启动命令来配置称为集群

consul-1

[root@localhost ~]# systemctl stop firewalld

[root@localhost ~]# setenforce 0

[root@localhost ~]# consul agent -server -node=consul1 -data-dir /opt/consul/data/ -config-dir /opt/consul/config/ -bind 192.168.10.20 -client 0.0.0.0 -enable-script-checks=true  -datacenter=kgc -bootstrap-expect=2

参数释义：
consul 命令
agent 启动一个代理
-server 以服务端启动
-node=consul1 当前节点在集群中名称
-data-dir /opt/consul/data/ 数据文件的目录
-config-dir /opt/consul/config/ 配置文件的目录
-bind 192.168.2.10 监听的ip
-client 0.0.0.0 指定的客户端代表所有的客户端
-enable-script-checks=true 开启心跳连接
-datacenter=kgc 数据中心的名称
-bootstrap-expect=2 至少两个节点形成集群

consul-2

[root@localhost ~]# systemctl stop firewalld

[root@localhost ~]# setenforce 0

[root@localhost ~]# consul agent -server -ui -node=consul2 -data-dir /opt/consul/data/ -config-dir /opt/consul/config/ -bind 192.168.10.30 -client 0.0.0.0 -enable-script-checks=true -datacenter=kgc -join 192.168.10.20

参数释义：
-ui ：图形化界面
-join：加入集群

consul-3

[root@localhost ~]# systemctl stop firewalld

[root@localhost ~]# setenforce 0

[root@localhost ~]# consul agent -server -ui -node=consul3 -data-dir /opt/consul/data/ -config-dir /opt/consul/config/ -bind 192.168.10.40 -client 0.0.0.0 -enable-script-checks=true -datacenter=kgc -join 192.168.10.20

client客户端

[root@localhost ~]# systemctl stop firewalld

[root@localhost ~]# setenforce 0

[root@localhost ~]# consul agent  -node=client -data-dir /opt/consul/data/ -config-dir /opt/consul/config/ -bind 192.168.10.10 -client 0.0.0.0 -enable-script-checks=true -datacenter=kgc -join 192.168.10.20

执行完后所有的主机都会阻塞终端，可以在第一台consul主机上另开一个终端去查看一下集群是否构建成功

[root@localhost ~]# consul members

Node     Address             Status  Type    Build  Protocol  DC   Segment

consul1  192.168.10.20:8301  alive   server  1.4.0  2         kgc  <all>

consul2  192.168.10.30:8301  alive   server  1.4.0  2         kgc  <all>

consul3  192.168.10.40:8301  alive   server  1.4.0  2         kgc  <all>

client   192.168.10.10:8301  alive   client  1.4.0  2         kgc  <default>

[root@localhost ~]# curl http://192.168.10.20:8500/v1/status/leader

"192.168.10.20:8300"

[root@localhost ~]# curl http://192.168.10.20:8500/v1/status/peers

["192.168.10.20:8300","192.168.10.30:8300","192.168.10.40:8300"]

[root@localhost ~]# consul info #查看集群的信息

agent:

	check_monitors = 0

	check_ttls = 0

	checks = 0

	services = 0

build:

	prerelease =

	revision = 0bddfa23

	version = 1.4.0

consul:

	acl = disabled

	bootstrap = false

	known_datacenters = 1

	leader = true

	leader_addr = 192.168.10.20:8300

	server = true

……………………

[root@localhost ~]# curl http://192.168.10.20:8500/v1/catalog/nodes?pretty #查看所有的节点，并且转换为json格式

[

    {

        "ID": "e280d23d-58b1-72b4-1c93-5a240f0ee1cd",

        "Node": "client",

        "Address": "192.168.10.10",

        "Datacenter": "kgc",

        "TaggedAddresses": {

            "lan": "192.168.10.10",

            "wan": "192.168.10.10"

        },

        "Meta": {

            "consul-network-segment": ""

        },

        "CreateIndex": 23,

        "ModifyIndex": 24

    },

………………

访问第二台consul-2的ip和端口（因为第一台是没有图形化界面的，只有第二台和第三台有，所以这儿我们可以去访问验证查看一下）

consul的基础命令

nosql 存储数据添加数据

1、创建或者更新数据

[root@localhost ~]# consul kv put redis/config/one 1 #添加数据到集群

Success! Data written to: redis/config/one

[root@localhost ~]# consul kv get redis/config/one  #查看

1

2、获取值

[root@localhost ~]# consul kv get -detailed redis/config/one

CreateIndex      379

Flags            0

Key              redis/config/one

LockIndex        0

ModifyIndex      379

Session          -

Value            1

3、查看详情

[root@localhost ~]# consul kv get -detailed redis/config/one

CreateIndex      379

Flags            0

Key              redis/config/one

LockIndex        0

ModifyIndex      379

Session          -

Value            1

4、删除

[root@localhost ~]# consul kv delete redis/config/one #删除

Success! Deleted key: redis/config/one

[root@localhost ~]# consul kv get redis/config/one

Error! No key exists at: redis/config/one

5、递归删除

[root@localhost ~]# consul kv put redis/config/one 1

Success! Data written to: redis/config/one

[root@localhost ~]# consul kv put redis/config/two 2

Success! Data written to: redis/config/two

[root@localhost ~]# consul kv delete -recurse redis

Success! Deleted keys with prefix: redis

[root@localhost ~]# consul kv get redis/two

Error! No key exists at: redis/two

6、列出指定前缀的内容

[root@localhost ~]# consul kv put redis/config/one 1

Success! Data written to: redis/config/one

[root@localhost ~]# consul kv put redis/config/two 2

Success! Data written to: redis/config/two

[root@localhost ~]# consul kv get -keys redis/config/

redis/config/one

redis/config/two

7、列出所有的键

[root@localhost ~]# consul kv get -keys

redis/

consul作为注册中心的功能

consul-1、consul-2、client客户端
注：另开终端执行

root@localhost ~]# git clone https://github.com/luojunyong/spring-cloud-examples.git

正克隆到 'spring-cloud-examples'...

remote: Enumerating objects: 700, done.

remote: Total 700 (delta 0), reused 0 (delta 0), pack-reused 700

接收对象中: 100% (700/700), 66.07 KiB | 0 bytes/s, done.

处理 delta 中: 100% (216/216), done.

consul-1 生产者

[root@localhost ~]# cd /root/spring-cloud-examples/spring-cloud-consul/spring-cloud-consul-producer

[root@localhost spring-cloud-consul-producer]# vim src/main/resources/application.properties

 3 spring.cloud.consul.host=192.168.10.40 #这儿写的是第三台consul-3的ip（也就是没有安装maven的那台主机）

[root@localhost spring-cloud-consul-producer]# source /etc/profile

[root@localhost spring-cloud-consul-producer]# mvn spring-boot:run

consul-2 生产者

[root@localhost ~]# cd /root/spring-cloud-examples/spring-cloud-consul/spring-cloud-consul-producer-2/

[root@localhost spring-cloud-consul-producer-2]# vim src/main/resources/application.properties

3 spring.cloud.consul.host=192.168.10.40

[root@localhost spring-cloud-consul-producer-2]# source /etc/profile

[root@localhost spring-cloud-consul-producer-2]# mvn spring-boot:run

client 消费者

[root@localhost ~]# cd /root/spring-cloud-examples/spring-cloud-consul/spring-cloud-consul-consumer/

[root@localhost spring-cloud-consul-consumer]# vim src/main/resources/application.properties

spring.cloud.consul.host=192.168.10.40

[root@localhost spring-cloud-consul-consumer]# source /etc/profile

[root@localhost spring-cloud-consul-consumer]# mvn spring-boot:run

第四台client另开一个终端去访问

[root@localhost ~]# curl 192.168.10.10:8503/call

helle consul

[root@localhost ~]# curl 192.168.10.10:8503/call

helle consul two

再次去图形化界面查看验证