nginx-- 利用set_by_lua進行優化

背景

服務是采用nginx+lua實作的，在nginx的配置中存在多處(共20多處)正則判斷，期望進行優化

location ~* /test.gif {
    rewrite_by_lua_file 'lua/edit.lua';
    if ($query_string ~* "pd=8(&|$)") {
        set $req_host inner.a.com;
        proxy_pass http://127.0.0.1:8481;
    }
    if ($query_string ~* "pd=3(&|$)") {
        set $req_host inner.b.com;
        proxy_pass http://127.0.0.1:8481;
    }
    if ($query_string ~* "ffs=.*(\{|%7B).*(%22|\")flag(%22|\")(:|%3A)(%22|\")?1(%22|\")+.*(\}|%7D)") {
            set $req_host inner.c.com;
        proxy_pass http://127.0.0.1:8481;
    }
}
           

改進方法

1、在nginx中定義pd、flag字段用來存儲pd、flag的值

set $pd 0;
set $flag 0;
           

2、在set_by_lua_file中使用正則進行提取pd、flag的值

set_by_lua_file:

local args = ngx.req.get_uri_args()
if args['action'] == 'test' then
    ngx.var.pd = '1'
else
    ngx.var.pd = '2'
end

local encodeRegex = "flow%22%3A%22([0-9]+)%22"
local normalRegex = 'flow":"([0-9]+)'
local str = 'logExtra=%7B%22st%22%3A%22other%22%2C%22rid%22%3A%22%22%2C%22pos%22%3A%220%22%2C%22flow%22%3A%2212%22%2C%22extra%22%3A%22%7B%7D%22%2C%22actionType%22%3A%22refresh_bottom%22%7D&r=l1562578644706'
local str1 = '&logExtra={"st":"other","rid":"","pos":"0","flow":"12","extra":"{}","actionType":"refresh_bottom"}&r=l1562578644706'
local normalFlow = ngx.re.match(str1, normalRegex)
local encodeFlow = ngx.re.match(str, encodeRegex)
if encodeFlow ~= nil and encodeFlow[1] ~= nil then
    ngx.var.flag = encodeFlow[1]
end
if normalFlow ~= nil and normalFlow[1] ~= nil then
    ngx.var.flag = normalFlow[1]
end
           

3、在test.gif中直接使用$pd $flag進行判斷

nginx.conf

set $flag 0;
        set $pd 0;

        location / {
            location /tcbox {
                set_by_lua_file $a '/test/set.lua';
                if ($flag = 1) {
                    content_by_lua_file '/test/caseone.lua';
                }
                if ($flag = 2) {
                    content_by_lua_file '/test/casetwo.lua';
                }
            }
        }