consul 介绍
Consul是HashiCorp公司推出的开源工具，用于实现分布式系统的服务发现与配置。与其他分布式服务注册与发现的方案，比如 Airbnb的SmartStack等相比，Consul的方案更“一站式”，内置了服务注册与发现框 架、分布一致性协议实现、健康检查、Key/Value存储、多数据中心方案，不再需要依赖其他工具（比如ZooKeeper等）。使用起来也较 为简单。Consul用Golang实现，因此具有天然可移植性(支持Linux、windows和Mac OS X)；安装包仅包含一个可执行文件，方便部署，与Docker等轻量级容器可无缝配合。
gitHub: https://github.com/hashicorp/consul
官网：https://www.consul.io/
官方说明：https://www.consul.io/docs/index.html
go api: https://godoc.org/github.com/hashicorp/consul/api
golang API 代码位置:https://github.com/hashicorp/consul/tree/master/api
consul 目录或文件说明
/tmp/consul: 数据存储
/Users/fox/bin/:程序安装目录
fox : mac系统用户的用户名
server 和 client 说明
本部分来自 https://blog.csdn.net/buxiaoxia/article/details/69788114#t2
CLIENT
CLIENT表示consul的client模式，就是客户端模式。是consul节点的一种模式，这种模式下，所有注册到当前节点的服务会被转发到SERVER，本身是不持久化这些信息。
简单的说，client 处理健康检查，注册服务等，但是这个注册只是转发到server中，如果有成千上万的服务，分别启动多个client,可以减少server 压力
SERVER
SERVER表示consul的server模式，表明这个consul是个server，这种模式下，功能和CLIENT都一样，唯一不同的是，它会把所有的信息持久化的本地，这样遇到故障，信息是可以被保留的。
SERVER-LEADER
中间那个SERVER下面有LEADER的字眼，表明这个SERVER是它们的老大，它和其它SERVER不一样的一点是，它需要负责同步注册的信息给其它的SERVER，同时也要负责各个节点的健康监测。
consul 安装
打开 https://www.consul.io/intro/getting-started/install.html ，在 Install Consul 下面有 binary package ，点击 这个 binary package （它是个超链接 https://www.consul.io/downloads.html），选择你要下载的版本
创建目录
mkdir -p /Users/fox/bin/打开这个目录 /Users/fox/bin/,然后下载consul
解压缩后 只有一个 单文件 consul
执行脚本
./consul输出
Usage: consul [--version] [--help] <command> [<args>]
Available commands are:
agent Runs a Consul agent
catalog Interact with the catalog
event Fire a new event
exec Executes a command on Consul nodes
force-leave Forces a member of the cluster to enter the "left" state
info Provides debugging information for operators.
join Tell Consul agent to join cluster
keygen Generates a new encryption key
keyring Manages gossip layer encryption keys
kv Interact with the key-value store
leave Gracefully leaves the Consul cluster and shuts down
lock Execute a command holding a lock
maint Controls node or service maintenance mode
members Lists the members of a Consul cluster
monitor Stream logs from a Consul agent
operator Provides cluster-level tools for Consul operators
reload Triggers the agent to reload configuration files
rtt Estimates network round trip time between nodes
snapshot Saves, restores and inspects snapshots of Consul server state
validate Validate config files/directories
version Prints the Consul version
watch Watch for changes in Consul设置环境配置
sudo vim /etc/paths.d/user_fox内容输入如下
/Users/fox/bin应用生效
source /etc/profile测试，在任何目录中，输入
consul输出
Usage: consul [--version] [--help] <command> [<args>]
Available commands are:
agent Runs a Consul agent
catalog Interact with the catalog
event Fire a new event
exec Executes a command on Consul nodes
force-leave Forces a member of the cluster to enter the "left" state
info Provides debugging information for operators.
join Tell Consul agent to join cluster
keygen Generates a new encryption key
keyring Manages gossip layer encryption keys
kv Interact with the key-value store
leave Gracefully leaves the Consul cluster and shuts down
lock Execute a command holding a lock
maint Controls node or service maintenance mode
members Lists the members of a Consul cluster
monitor Stream logs from a Consul agent
operator Provides cluster-level tools for Consul operators
reload Triggers the agent to reload configuration files
rtt Estimates network round trip time between nodes
snapshot Saves, restores and inspects snapshots of Consul server state
validate Validate config files/directories
version Prints the Consul version
watch Watch for changes in Consulconsul 参数说明
-dev 开发者模式 该节点的启动不能用于生产环境，因为该模式下不会持久化任何状态
该启动模式仅仅是为了快速便捷的启动单节点consul
该节点处于server模式
该节点是leader
该节点是一个健康节点
-ui 启动自有主机的界面
-bootstrap-expect 1 集群节点，表示等待多少个节点再启动，这里是1个，一个就启动
-bind=127.0.0.1 绑定IP ，本机IP地址，内网IP
-advertise-wan=10.23.123.12 绑定外网ip
-node=node1 节点名称，如果没有，默认是主机名
-server 设置为服务端
-data-dir /tmp/consul 数据存储目录为 /tmp/consul
-datacenter=dc1 数据中心
更多请看
https://www.consul.io/docs/agent/options.html
consul agent server client
agent可以运行在server或者client模式
consul agent server 服务端
consul agent server 服务端启动
consul agent -dev -server -bootstrap-expect 1 -data-dir /tmp/consul -node=node1停止
Ctrl+C #按键如果你按错了那么使用强制停止
ps -ef |grep consul输出
501 831 813 0 1:12下午 ttys001 0:02.37 consul agent -dev -config-dir /Users/fox/bin/consul.d/
501 890 813 0 1:16下午 ttys001 0:00.00 grep consul第一行就是要停止的进程
kill -9 831查看成员
consul members服务操作
创建一个 服务
新建目录
mkdir -p /Users/fox/bin/consul.d创建web服务和service2服务
echo '{"service": {"name": "web", "tags": ["rails"], "port": 801}}' >/Users/fox/bin/consul.d/web.json
echo '{"service": {"name": "service2", "tags": ["rails"], "port": 802}}' >/Users/fox/bin/consul.d/service2.json启动代理(你要先关闭之前开启的那个代理哦)
consul agent -dev -config-dir /Users/fox/bin/consul.d/查询服务
DNS 查询
服务的DNS名称是 NAME.service.consul
service2:服务名称
web:服务名称
dig @127.0.0.1 -p 8600 service2.service.consul输出
; <<>> DiG 9.9.7-P3 <<>> @127.0.0.1 -p 8600 service2.service.consul
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56742
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;service2.service.consul. IN A
;; ANSWER SECTION:
service2.service.consul. 0 IN A 127.0.0.1
;; Query time: 0 msec
;; SERVER: 127.0.0.1#8600(127.0.0.1)
;; WHEN: Thu Jan 18 13:29:46 CST 2018
;; MSG SIZE rcvd: 68HTTP API 查询
curl http://localhost:8500/v1/catalog/service/service2输出
[
{
"ID": "e3e23dc4-f3c7-24bb-e35a-53ae6bcae58a",
"Node": "fox",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"wan": "127.0.0.1"
},
"NodeMeta": {
"consul-network-segment": ""
},
"ServiceID": "service2",
"ServiceName": "service2",
"ServiceTags": [
"rails"
],
"ServiceAddress": "",
"ServicePort": 802,
"ServiceEnableTagOverride": false,
"CreateIndex": 6,
"ModifyIndex": 6
}
]查询健康
curl 'http://localhost:8500/v1/health/service/service2?passing'输出
[
{
"Node": {
"ID": "e3e23dc4-f3c7-24bb-e35a-53ae6bcae58a",
"Node": "fox",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"wan": "127.0.0.1"
},
"Meta": {
"consul-network-segment": ""
},
"CreateIndex": 5,
"ModifyIndex": 6
},
"Service": {
"ID": "service2",
"Service": "service2",
"Tags": [
"rails"
],
"Address": "",
"Port": 802,
"EnableTagOverride": false,
"CreateIndex": 6,
"ModifyIndex": 6
},
"Checks": [
{
"Node": "fox",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "Agent alive and reachable",
"ServiceID": "",
"ServiceName": "",
"ServiceTags": [],
"Definition": {},
"CreateIndex": 5,
"ModifyIndex": 5
}
]
}
]
Consul Web界面
加入 -ui 参数， 启动自有主机的界面
启动代理(你要先关闭之前开启的那个代理哦)
consul agent -dev -ui -config-dir /Users/fox/bin/consul.d/等待一会，浏览器中输入如下，就可以看到UI界面了
http://localhost:8500/uiConsul 集群 docker版
请打开网址查看
http://blog.csdn.net/fenglailea/article/details/79098246
Consul 集群
稍后添加
A&Q
Error starting agent: Failed to start Consul server: Failed to start RPC layer: listen tcp 127.0.0.1:8300: bind: address already in use
原因：你已经启动一个了，要么关闭它，要么继续使用已经启动过得
用这个命令查看
ps -ef |grep consulhttps://segmentfault.com/a/1190000005005227
https://www.jianshu.com/p/28c6bd590ca0
http://tonybai.com/2015/07/06/implement-distributed-services-registery-and-discovery-by-consul/
https://www.cnblogs.com/newP/p/6349316.html