openresty lua 使用

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简单例子

打印请求头

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server {
  listen       8000;
  client_max_body_size 512m;
  access_log /data/logs/extsvc.log nginxlog_extsvc_json;
  set $req_header "";
        header_filter_by_lua '
            local h = ngx.req.get_headers()
            for k, v in pairs(h) do
            ngx.var.req_header=ngx.var.req_header..k..": "..v.."; "
            end
        ';

  location / {
    proxy_pass http://service:8080/;
    # 配置缓存大小
    proxy_buffers 256 4k;
    # 关闭磁盘缓存读写减少i/o
    proxy_max_temp_file_size 0;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_connect_timeout 1200;
    proxy_send_timeout 1200;
    proxy_read_timeout 1200;
  }
}

连接mysql

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--1) 定义数据库连接属性
local props = {
    host = "xxxx",
    port = 3306,
    database = "xxx",
    user = "xxx",
    password = "xxxx",
    charset = 'utf8mb4',
    max_packet_size = 1024 * 1024
}
-- 2) 自定义close函数
local function close_db(db)
    if not db then
        return
    end
      
    --  连接池机制：不调用close,选择keepalive 确保性能
    local pool_max_idle_time = 10000 --毫秒  
    local pool_size = 100 --连接池大小  
    local ok, err = db:set_keepalive(pool_max_idle_time, pool_size)  
    if not ok then  
        -- ngx.say("set keepalive error : ", err)  
        ngx.log(ngx.ERR, "set keepalive error : ", err)
    end 
end
-- 3) 引入mysql实例
local mysql = require("resty.mysql")
-- 4) 创建实例
local db, err = mysql:new()
if not db then
    -- ngx.say("new mysql error : ", err)
    ngx.log(ngx.ERR, "new mysql error : ", err)
    return
end
 
--4) 设置超时时间
db:set_timeout(10000)
 
-- 6) 建立连接
local res,err,errno,sqlstate = db:connect(props)
-- 备注：异常判断,异常消息统一处理
if not res then
    ngx.log(ngx.ERR, "connect to mysql error:", err,", errno:", errno,", sqlstate:", sqlstate)
    return close_db(db)
end
ngx.say("connectd")
-- 获取access_token
ngx.say(ngx.var.arg_access_token)
ngx.log(ngx.INFO, ngx.var.arg_access_token)
-- 7) sql 语句操作 -->过程省略

local select_sql = "show PROCESSLIST"
res, err, errno, sqlstate = db:query(select_sql)
if not res then
    ngx.say("select table error :", err,", errno", errno, ", sqlstate : ",sqlstate)
    return close_db(db)
end
ngx.say(sqlstate)

-- 多条'结果集'的处理
for i, row in ipairs(res) do
    -- ngx.say(row.username, row.phone)
    for key,value in pairs(row) do
        ngx.say("select row", i," : ", key, " = ", value)
    end
    ngx.say("<br/>===================")
end

-- 8) 关闭连接 -->由于使用连接池,不需要每次都使用密码
close_db(db)

修改响应体

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location / {
    root   html;
    index  index.html index.htm;
    default_type text/plain;
    set $qw_corp_id "";
    #content_by_lua_file /usr/local/openresty/nginx/lua/init.lua; 
    rewrite_by_lua_file /usr/local/openresty/nginx/lua/init.lua;
    #body_filter_by_lua '
#           local str = ngx.arg[1]
#           str = string.gsub(str, "CHANGE_URL", ngx.var.host)
#           ngx.arg[1] = str
#           ';
    #sub_filter_types *;
    #sub_filter_once off;
    #sub_filter 'CHANGE_URL'  $host;
    #proxy_set_header X-My-Header $qw_corp_id;
    #proxy_pass http://xxxx;

}

打印响应体

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server {
listen 800;
location / {
        default_type text/html;
        lua_need_request_body on;
            set $resp_body "";
            body_filter_by_lua_block {
                local cjson = require("cjson")
                local resp_body = ngx.arg[1]
                ngx.ctx.buffered = (ngx.ctx.buffered or "") .. resp_body
                if ngx.arg[2] then
                    ngx.var.resp_body = ngx.ctx.buffered
                    ngx.log(ngx.ERR, ngx.var.resp_body)
                    if ngx.var.resp_body == "ret_body" then
                        ngx.log(ngx.ERR,"判断正确\n")
                    else
                        ngx.log(ngx.ERR,"其他内容\n")
                    end

                    local success, response_json = pcall(cjson.decode, ngx.var.resp_body)
                    if success then
                        -- 打印JSON内容
                        local response_json_str = cjson.encode(response_json)
                        ngx.log(ngx.ERR, "打印JSON内容" .. response_json_str .. "\n")
                    else
                        -- 打印原始响应内容
                        ngx.log(ngx.ERR, "打印原始响应内容:" .. ngx.var.resp_body .. "\n")
                    end

                end
            }
        proxy_pass http://127.0.0.1:801;
    }
}