consul的基本使用

### 安装
[centos7上consul的安装](http://www.cnblogs.com/wang2650/p/5473881.html)

wget https://releases.hashicorp.com/consul/0.6.4/consul_0.6.4_linux_amd64.zip
consul -v
json格式化
```shell
yum -y install epel-release
yum install jq -y

consul agent -server -bootstrap-expect 2 -data-dir /tmp/consul -node=n1 -bind=192.168.139.194 -dc=dc1
consul agent -server -bootstrap-expect 2 -data-dir /tmp/consul -node=n2 -bind=192.168.139.218 -dc=dc1
consul agent -server -bootstrap-expect 2 -data-dir /tmp/consul -node=n2 -bind=192.168.139.193 -dc=dc1
consul agent -server -bootstrap-expect 2 -data-dir /tmp/consul -node=n2 -bind=192.168.139.161 -dc=dc1
```
在第一个节点上

consul join 192.168.139.218


#######################################
如果发现集群有问题，就 rm -rf /tmp/consul
mkdir /tmp/consul
#####################################
[consul入门](http://blog.csdn.net/viewcode/article/details/45915179)
[服务发现系统consul介绍](http://www.codeweblog.com/%E6%9C%8D%E5%8A%A1%E5%8F%91%E7%8E%B0%E7%B3%BB%E7%BB%9Fconsul%E4%BB%8B%E7%BB%8D/)
# 例子1
mkdir /etc/consul.d/
echo '{"service": {"name": "web", "tags": ["rails"], "port": 80}}' >/etc/consul.d/web.json
consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul -bind=192.168.139.218 -config-dir /etc/consul.d

dig @127.0.0.1 -p 8600 web.service.consul
dig @127.0.0.1 -p 8600 web.service.consul SRV
curl http://localhost:8500/v1/catalog/service/web |jq

curl http://localhost:8500/v1/catalog/nodes |python -m json.tool
dig @127.0.0.1 -p 8600 mcompute616.node.consul

健康检查
echo '{"check": {"name": "ping", "script": "ping -c1 www.baidu.com >/dev/null", "interval": "30s"}}' >/etc/consul.d/ping.json
echo '{"service": {"name": "web", "tags": ["rails"], "port": 80 ,"check": {"script": "curl localhost:80 >/dev/null 2>&1", "interval": "10s"}}}' >/etc/consul.d/web.json
curl -s http://localhost:8500/v1/health/state/any | python -m json.tool

查看所有
curl -v http://127.0.0.1:8500/v1/kv/?recurse | python -m json.tool

curl -X PUT -d 'test' http://127.0.0.1:8500/v1/kv/web/key1
curl -X PUT -d 'test' http://127.0.0.1:8500/v1/kv/web/key2?flags=42
curl -X PUT -d 'test' http://127.0.0.1:8500/v1/kv/web/web/sub/key3

查看一个
curl -s http://127.0.0.1:8500/v1/kv/web/key1|python -m json.tool
删除所有
curl -X DELETE http://127.0.0.1:8500/v1/kv/web/sub?recurse

修改（不好使呀）
curl -X PUT -d 'newval' http://127.0.0.1:8500/v1/kv/web/key1?cas=106
curl -X PUT -d 'newval' http://127.0.0.1:8500/v1/kv/web/key1?cas=106
curl -s http://127.0.0.1:8500/v1/kv/web/key1|python -m json.tool


### 例子2
consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul -node=agent-one -bind=192.168.139.218
#consul agent -data-dir /tmp/consul -node=agent-one -bind=192.168.139.218
consul agent -server -data-dir /tmp/consul
consul agent -data-dir /tmp/consul -node=agent-two -bind=192.168.139.194
consul agent -data-dir /tmp/consul -node=agent-three -bind=192.168.139.193

第一个节点
consul join 192.168.139.194 192.168.139.193
consul members
consul info

### 例子3
consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul -bind=192.168.139.218 -config-dir /etc/consul.d
consul agent -data-dir /tmp/consul -join=192.168.139.218 -bind=192.168.139.194


### 三台机器的测试
https://blog.coding.net/blog/intro-consul?type=hot
http://www.bubuko.com/infodetail-800623.html
consul agent -server -bootstrap -data-dir /tmp/consul -bind=192.168.139.218
consul agent -server -data-dir /tmp/consul -bind=192.168.139.194
consul agent -server -data-dir /tmp/consul -bind=192.168.139.193
第一个节点
consul join 192.168.139.194 192.168.139.193
ctl+c 断开第一个节点，之后
consul agent -server -data-dir /tmp/consul -bind=192.168.139.218
consul join 192.168.139.194 192.168.139.193

curl -X PUT -d '{"Datacenter": "dc1", "Node": "mysql-1", "Address": "mysql-1.node.consul","Service": {"Service": "mysql", "tags": ["master","v1"], "Port": 3306}}' http://127.0.0.1:8500/v1/catalog/register
curl -X PUT -d '{"Datacenter": "dc1", "Node": "mysql-2", "Address": "mysql-2.node.consul","Service": {"Service": "mysql", "tags": ["slave","v1"], "Port": 3306}}' http://127.0.0.1:8500/v1/catalog/register

curl http://127.0.0.1:8500/v1/catalog/service/mysql
curl http://127.0.0.1:8500/v1/catalog/service/mysql|python -m json.tool
curl 127.0.0.1:8500/v1/catalog/nodes |python -m json.tool
dig @127.0.0.1 -p 8600 mysql.service.consul SRV

### 健康检查
kill掉一个节点，consul members处于fail状态
curl http://localhost:8500/v1/health/state/critical

### K/V存储
curl -v http://localhost:8500/v1/kv/?recurse |python -m json.tool
curl -X PUT -d 'test' http://localhost:8500/v1/kv/mysql/key2?flags=43
curl -X DELETE http://localhost:8500/v1/kv/mysql/key2?recurse
curl -X PUT -d 'newval' http://localhost:8500/v1/kv/mysql/key1?flags=100

更新index：
curl "http://localhost:8500/v1/kv/mysql/key1?index=101&wait=5s"

##################################

consul agent -atlas-join -atlas=ATLAS_USERNAME/infrastructure -atlas-token="YOUR_ATLAS_TOKEN"

curl https://mysql.service.consul/v1/kv/my-key

{"service": {"name" : "test","port" : 9999,"check":{ "tcp": "127.0.0.1:9999", "interval": "10s" }} }

[consul-template入门篇](http://blog.csdn.net/daiyudong2020/article/details/53559008)

docker run -d --name=consul --net=host gliderlabs/consul-server -bootstrap -bind=192.168.0.149
docker run -d --name=registrator --net=host --volume=/var/run/docker.sock:/tmp/docker.sock gliderlabs/registrator:latest consulkv://localhost:8500/hello

consul-template -consul 127.0.0.1:8500 -template /root/nginx_web.ctmpl:/usr/local/nginx/conf/nginx.conf:"/usr/local/nginx/sbin/nginx -s reload"


curl -X PUT -d 'test' http://localhost:8500/v1/kv/hello/hehe?flags=43
curl -v http://localhost:8500/v1/kv/?recurse |python -m json.tool


### nginx的例子 ###
模板语言https://book-consul-guide.vnzmi.com/11_consul_template.html

删除所有
curl -X DELETE http://127.0.0.1:8500/v1/kv/?recurse
curl --request PUT --data "192.168.139.161" http://localhost:8500/v1/kv/myserver/mcontroller605
curl --request PUT --data "192.168.139.193" http://localhost:8500/v1/kv/myserver/mcompute605
curl -s http://localhost:8500/v1/kv/myserver?recurse | jq

consul-template -consul-addr 127.0.0.1:8500 -template /root/nginx_web.ctmpl:/usr/local/nginx/conf/nginx.conf:"/usr/local/nginx/sbin/nginx -s reload" -once
consul-template -config ./tmpl.json -once

nginx_web.ctmpl
```go
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
upstream app {
{{range ls "myserver/" }}
server {{.Value}} weight=5;{{end}}
}
server {
listen 80;
server_name localhost;
location / {
proxy_pass http://app;
}
}
}
```
tmpl.json
```javascript
consul = "127.0.0.1:8500"
template {
source = "./nginx_web.ctmpl"
destination = "/usr/local/nginx/conf/nginx.conf"
command = "/usr/local/nginx/sbin/nginx -s reload"
}
```
### consul-template 的helloword:
ls
config.ctmpl tmpl.json

tmpl.json
```javascript
consul = "127.0.0.1:8500"
template {
source = "./config.ctmpl"
destination = "./config.py"
command = "python ./config.py"
}
···
config.ctmpl
```python
#!/usr/bin/python
#coding:utf-8

#bottle
iplist = [ {{range service "web"}} "{{.Address}}",{{end}} ]
port = 8080

for ip in iplist:
print ip
```
consul-template -config ./tmpl.json -once
生成config.py
```shell
cat /etc/consul.d/web.json
{"service": {"name": "web", "tags": ["rails"], "port": 80 ,"check": {"script": "curl localhost:80", "interval": "10s"}}}

curl http://127.0.0.1:8500/v1/catalog/service/web|python -m json.tool
```

### kv的例子 ###
https://python-consul.readthedocs.io/en/latest/#consul-status

yum install python-virtualenv
virtualenv mysite
source mysite/bin/activate
pip install python-consul

a.py
```python
import consul

c = consul.Consul()

# poll a key for updates
index = None
while True:
index, data = c.kv.get('foo', index=index)
print data['Value']

# in another process
c.kv.put('foo', 'bar')
```
### 基本使用 ###
curl -v 是显示详细， -s是只显示结果
设置值
curl --request PUT --data "hello" http://localhost:8500/v1/kv/my-key
查所有值
curl -v http://localhost:8500/v1/kv/?recurse |python -m json.tool
查某个值
curl -v http://localhost:8500/v1/kv/my-key |python -m json.tool
显示值的value
curl -s http://127.0.0.1:8500/v1/kv/my-key| jq -r .[0]'.Value'|base64 -d
curl -s http://127.0.0.1:8500/v1/kv/foo| jq -r .[0]'.Value'|base64 -d
删除所有
curl -X DELETE http://127.0.0.1:8500/v1/kv/?recurse