初识Consul

$ wget https://releases.hashicorp.com/consul/0.8.5/consul_0.8.5_linux_amd64.zip
$ unzip consul_0.8.5_linux_amd64.zip
$ mv consul /usr/local/bin/

$ consul
usage: consul [--version] [--help] <command> [<args>]
Available commands are:
  agent          Runs a Consul agent
  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

consul agent -dev

dev@ubuntu ~$ consul members
Node    Address         Status  Type    Build  Protocol  DC
ubuntu  127.0.0.1:8301  alive   server  0.7.2  2         dc1

dev@ubuntu ~$ curl localhost:8500/v1/catalog/nodes
[    {
       "Node": "ubuntu",
       "Address": "127.0.0.1",
       "TaggedAddresses": {
             "lan": "127.0.0.1",
             "wan": "127.0.0.1"        },
        "CreateIndex": 4,
       "ModifyIndex": 5    }]

cd ~/consul// 创建etc 目录用于存放配置文件mkdir etc// 创建web.json 配置文件echo '{"service": {"name": "web", "tags": ["nginx"], "port": 80}}' | tee ~/consul/etc/web.json// 重启consul，并指定配置文件目录consul agent -dev -config-dir=/home/dev/consul/etc

# 创建配置目录$ mkdir /etc/consul.d# 创建一个服务定义配置文件，假设有一个名为web服务，它运行在80端口。$ echo '{"service": {"name": "web", "tags": ["rails"], "port": 80}}' >/etc/consul.d/web.json

$ consul agent -dev -bind=192.168.50.210 -config-dir /etc/consul.d/
==> Starting Consul agent...
==> Consul agent running!

$ dig @127.0.0.1 -p 8600  rails.web.service.consul
; <<>> DiG 9.10.3-P4-Ubuntu <<>> @127.0.0.1 -p 8600 rails.web.service.consul
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44287;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;rails.web.service.consul.    IN    A
;; ANSWER SECTION:
rails.web.service.consul. 0    IN    A    192.168.2.210;; Query time: 0 msec
;; SERVER: 127.0.0.1#8600(127.0.0.1);; WHEN: Tue May 09 10:58:16 CST 2017;; MSG SIZE  rcvd: 58

$ curl http://localhost:8500/v1/catalog/service/web[    {        "ID": "b76ff298-accd-05ff-8c64-5d79d866dfa9",        "Node": "dev-master-01",        "Address": "192.168.50.210",        "TaggedAddresses": {
           "lan": "192.168.50.210",
           "wan": "192.168.50.210"        },
       "NodeMeta": {},
       "ServiceID": "web",
       "ServiceName": "web",
       "ServiceTags": [
           "rails"        ],
       "ServiceAddress": "",
       "ServicePort": 80,
       "ServiceEnableTagOverride": false,
       "CreateIndex": 7,
       "ModifyIndex": 7    }]