proxy_cache_path /tmp/ngx_cache/proxy_cache_dir levels=1:2 keys_zone=ngx_cache:10m inactive=30m max_size=500m;
proxy_temp_path  /tmp/ngx_cache/proxy_temp_dir;

server {
    proxy_cache ngx_cache;
    proxy_cache_valid 10m;
    add_header  Nginx-Cache "$upstream_cache_status";

    set $no_cache '';
    set_by_lua $cache_key "
        local no_cache = false
        if ngx.var.http_cookie and string.find(ngx.var.http_cookie, 'user') then
            # 带 cookie 的请求(比如登录用户)忽略缓存
            no_cache = true
        end

        if ngx.var.uri == '/api/test' then
        	  #某些 URL 的请求强制缓存，不管是否有 cookie
            no_cache = false
        end

        if no_cache then
            #确定忽略缓存就不再计算 cache_key
            ngx.var.no_cache = 'true'

            return ngx.var.uri
        end

        local uri_args = ngx.req.get_uri_args()
        local args = {}
        for k, v in pairs(uri_args) do
            if k and v and type(v) == 'string' then
                if k == 'count' or k == 'sort' or k == 'page' then
                    #过滤掉非法请求参数
                    args[#args+1] = k .. '=' .. v
                end
            end
        end

        if #args > 0 then
            table.sort(args)
            return ngx.var.uri .. '?' .. table.concat(args, '&')
        else
            return ngx.var.uri
        end
    ";
    
    proxy_cache_key $cache_key;
    proxy_no_cache $no_cache;
    proxy_cache_bypass $no_cache;
    
    location / {
	     proxy_pass http://localhost:8080;
    }
}