openresty 学习笔记五:访问RabbitMQ消息队列
之前通过比较选择，决定采用RabbitMQ这种消息队列来做中间件，目的舒缓是为了让整个架构的瓶颈环节。这里是做具体实施，用lua访问RabbitMQ消息队列。
RabbitMQ消息队列有几个比较重要的概念：生产者Producer,消费者Consumer,交换器Exchanges,队列Queues
我的简单理解
生产者，发布消息入队的用户。
消费者，订阅队列获取消息的用户。
交换器，消息可以不指定某个具体队列，而是发送给交换器，通过不同类型交换器的规则和router key分配到具体的队列。
队列，消息队列载体，每个消息都会被投入到一个或多个队列。
lua 要访问 RabbitMQ 目前只找到一个通过STOMP协议连接的库lua-resty-rabbitmqstomp，前面已经介绍了这个STOMP，RabbitMQ也需要安装适配器才可以。该库我查不到声明exchange和queues并进行绑定的方法，只可以实现发送消息到指定交换器和订阅指定队列。文章来源地址:https://www.yii666.com/article/758093.html
二次封装
根据自己的业务需要，先稍微做了个二次封装，主要是封装连接步骤和send的方法，同时规范返回值网址:yii666.com
local rabbitmq = require "resty.rabbitmqstomp"
local _M = {}
_M._VERSION = '0.01'
local mt = { __index = _M }
function _M.new(self, opts)
opts = opts or {}
return setmetatable({
mq_host = opts.host or '127.0.0.1',
mq_port = opts.port or 61613,
mq_timeout = opts.timeout or 10000,
mq_user = opts.username or 'guest',
mq_password = opts.password or 'guest',
mq_vhost = opts.vhost or "/"}, mt)
end
function _M.get_connect(self)
local mq, err = rabbitmq:new({ username = self.mq_user,
password = self.mq_password,
vhost = self.mq_vhost })
if not mq then
return false,err
end
mq:set_timeout(self.mq_timeout)
local ok, err = mq:connect(self.mq_host,self.mq_port)
if not ok then
return false,err
end
return true,mq
end
function _M.send(self , destination, msg)
local ret, client = self:get_connect()
if not ret then
return false,client
end
local send_receipt_id = ngx.now()*1000
local headers = {}
headers["destination"] = destination
headers["receipt"] = send_receipt_id
headers["app-id"] = "luaresty"
headers["persistent"] = "true"
headers["content-type"] = "application/json"
local ok, err = client:send(msg, headers)
if not ok then
return false,err
end
local _,str_start = string.find(ok, "receipt%-id", 1)
local str_end = string.find(ok, "\n\n", 1)
if str_start == nil or str_end == nil then
return false,"send receipt not receive"
end
local receipt_id = string.sub(ok, str_start + 2 ,str_end - 1)
if receipt_id ~= send_receipt_id then
return false,"receipt id not right"
end
local ok, err = client:set_keepalive(10000, 10000)
return true,send_receipt_id
end
return _M
文章地址https://www.yii666.com/article/758093.html
使用示例
local rabbitmq = require ("myRabbitmq")
local mq = rabbitmq:new(config)
local ok , err = mq:send(destination,data)
if not ok then
ngx.log(ngx.ERR, "failed to send mq :", err)
end