nginx通过lua-nginx-module自定义转发请求

nginx通过lua-nginx-module自定义转发请求。
！！！注意事项：
1.当请求body大于 client_body_buffer_size 默认值8k或16k时，请求报文将会被nginx缓存到硬盘，此时 ngx.req.get_body_data() 无法获取到body正文。请修改nginx client_body_buffer_size 128k，或者更大。典型案例：如果是转发multipart/form-data类型，不去修改大小，就会转发失败。
2.Web 应用服务器-OpenResty

zdy_proxy.lua

local cookie = require "resty.cookie"
local http = require "resty.http"
local upload = require "resty.upload"
local json = require "cjson"
local resp = require "ngx.resp"
local redis = require "resty.redis"

-- redis
local function redis_func(key, value, expires_in)
    local rds = redis:new()
    if not rds then
        error("rds is nil")
    end
    rds:set_timeout(1000) -- 设置超时时间为 1000 毫秒

    local ok, err = rds:connect("127.0.0.1", 6379) -- 连接 Redis 服务器
    if not ok then
        rds:close() -- 连接失败需要及时关闭释放连接
        error("failed to connect : " .. err)
    end

    local res, err = rds:auth("123456") -- 身份认证
    if not res then
        error("failed to authenticate: " .. err)
    end

    ngx.log(ngx.DEBUG, "SET " .. key .. " " .. value .. " EX " .. expires_in)
    ok, err = rds:set(key, value, "EX", expires_in) -- 向 Redis 写入数据
    if not ok then
        error("failed to set dog: " .. err)
    end
    ngx.log(ngx.DEBUG, "set result: ", ok)

    rds:close() -- 关闭连接
    return ok
end

-- 输入响应内容，ngx.exit退出
local function response_func(resp_status, resp_headers, resp_body)
    ngx.status = resp_status
    --ngx.header = resp_headers -- ！！！这种方式无法设置响应头，暂时未找到bug原因
    for v, m in pairs(resp_headers) do
        resp.add_header(v, m)
    end
    ngx.flush(true) -- 同步输出
    ngx.print(resp_body)
    ngx.exit(ngx.HTTP_OK)
end

-- 代理转发
local function proxy_func(proxy_url)
    local client = http.new()
    if not client then
        error("client is nil")
    end
    client:set_timeout(30 * 1000)

    local request_header = ngx.req.get_headers()
    local request_method = ngx.req.get_method()
    ngx.req.read_body()
    local request_body = ngx.req.get_body_data() -- 当请求body大于 client_body_buffer_size 默认值8k或16k时，请求报文将会被nginx缓存到硬盘，此时 ngx.req.get_body_data() 无法获取到body正文。请修改nginx client_body_buffer_size 128k，或者更大。！！！典型案例：如果是转发multipart/form-data类型，不去修改大小，就会转发失败

    ngx.log(ngx.DEBUG, "request_url ", proxy_url)
    ngx.log(ngx.DEBUG, "request_method ", request_method)
    ngx.log(ngx.DEBUG, "request_header ", json.encode(request_header))
    ngx.log(ngx.DEBUG, "request_body ", request_body)

    local ok, err =
        client:request_uri(
        proxy_url,
        {
            method = request_method,
            headers = request_header,
            body = request_body,
            ssl_verify = false -- 验证SSL证书是否与主机名匹配
        }
    )

    ngx.log(ngx.DEBUG, "ok type is ", type(ok))
    ngx.log(ngx.DEBUG, "err type is ", type(err))

    if not ok then -- 检查请求是否成功
        error("failed to request : " .. err)
    end

    local response_body = ok.body
    local response_headers = ok.headers
    local response_status = ok.status

    ngx.log(ngx.DEBUG, "response_status ", json.encode(response_status))
    ngx.log(ngx.DEBUG, "response_headers ", json.encode(response_headers))
    ngx.log(ngx.DEBUG, "response_body ", json.encode(response_body))

    return response_status, response_headers, response_body
end

-- 主函数
local function mian_func()
    local request_url = ngx.var.request_uri
    ngx.log(ngx.DEBUG, "request_url=", request_url)

    if string.find(request_url, "api/test/", 1, true) ~= nil then -- api/test开头的就要通过解析参数转发
        ngx.log(ngx.DEBUG, "=============== start countyCode proxy ===============")

        local countyCode = nil

        -- 解析参数，获取countyCode begin
        local args = ngx.req.get_uri_args() -- 先分析url参数，如：/test?foo=bar&bar=baz&countyCode=1111
        if type(args) == "table" and _G.next(args) ~= nil then -- 排除args是空的table
            countyCode = args["countyCode"]
        else -- 从body的内容获取
            ngx.req.read_body()
            args = ngx.req.get_body_data()
            args = json.decode(args)
            countyCode = args["reqBody"]["countyCode"]
        end
        ngx.log(ngx.DEBUG, "args ", json.encode(args))
        -- end

        if countyCode ~= nil and string.len(countyCode) > 0 then
            if countyCode == "1001" then -- 根据 countyCode 进行转发
                local resp_status, resp_headers, resp_body = proxy_func("http://127.0.0.1:8045" .. request_url)
                response_func(resp_status, resp_headers, resp_body)
            else
                local resp_status, resp_headers, resp_body = proxy_func("http://127.0.0.1:8002" .. request_url)
                response_func(resp_status, resp_headers, resp_body)
            end
        else
            error("failed get param countyCode") -- 参数解释失败抛出异常
        end
    elseif string.find(request_url, "/oauth2/get/token", 1, true) ~= nil then -- 统一身份认证
        local resp_status, resp_headers, resp_body = proxy_func("http://127.0.0.1:8045" .. request_url)
        -- 设置缓存 begin
        local res_data = json.decode(resp_body)
        if not res_data["error"] then -- 成功获取到了token
            local key = "Cache@" .. res_data["access_token"]
            local value = '{"TypeName":"string","Value":' .. json.encode(resp_body) .. "}"
            local expires_in = tonumber(res_data["expires_in"])
            redis_func(key, value, expires_in)
        end
        -- end
        response_func(resp_status, resp_headers, resp_body)
    else
        -- 转发正常请求
        local resp_status, resp_headers, resp_body = proxy_func("http://127.0.0.1:8011" .. request_url)
        response_func(resp_status, resp_headers, resp_body)
    end
end

-- runing......
mian_func()

nginx.conf

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
error_log  logs/error.log  debug;

pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       8011;
        server_name  localhost;
        
        lua_http10_buffering off;


        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        #location / {
        #    root   html;
        #    index  index.html index.htm;
        #}

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

        # proxy the PHP scripts to Apache listening on 127.0.0.1:80
        #
        #location ~ \.php$ {
        #    proxy_pass   http://127.0.0.1;
        #}

        # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
        #
        #location ~ \.php$ {
        #    root           html;
        #    fastcgi_pass   127.0.0.1:9000;
        #    fastcgi_index  index.php;
        #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
        #    include        fastcgi_params;
        #}

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #    deny  all;
        #}

        #==========================================================
		location / {
			default_type 'text/plain';
            charset 'utf-8';
            #指定由lua解析
			content_by_lua_file lua/zdy_proxy.lua;
            client_body_buffer_size 50M;
		}
		#==========================================================
    }


    # another virtual host using mix of IP-, name-, and port-based configuration
    #
    #server {
    #    listen       8000;
    #    listen       somename:8080;
    #    server_name  somename  alias  another.alias;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}


    # HTTPS server
    #
    #server {
    #    listen       443 ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

}

参考文献
openresty/lua-nginx-module
LuatOS
OpenResty