log_by_lua ---------- **语法:** *log_by_lua &lt;lua-script-str&gt;* **环境:** *http, server, location, location if* **阶段:** *log* 在 `log` 请求处理阶段执行内嵌在`<lua-script-str>`的 Lua 代码。它不替代当前access的日志，而是在其后执行。 注意，当前环境中以下 API 函数当前是被禁用的： * 输出API函数类（例如：[ngx.say](#ngxsay) 和 [ngx.send_headers](#ngxsend_headers)） * 控制API函数类（例如：[ngx.exit](#ngxexit) 和 [ngx.exec](#ngxexec)） * 子请求函数类（例如：[ngx.location.capture](#ngxlocationcapture) 和 [ngx.location.capture_multi](#ngxlocationcapture_multi)） * cosocket 函数类（例如：[ngx.socket.tcp](#ngxsockettcp) 和 [ngx.req.socket](#ngxreqsocket)） 这是一个收集 [$upstream_response_time](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#var_upstream_response_time) 平均处理的例子： ```nginx lua_shared_dict log_dict 5M; server { location / { proxy_pass http://mybackend; log_by_lua ' local log_dict = ngx.shared.log_dict local upstream_time = tonumber(ngx.var.upstream_response_time) local sum = log_dict:get("upstream_time-sum") or 0 sum = sum + upstream_time log_dict:set("upstream_time-sum", sum) local newval, err = log_dict:incr("upstream_time-nb", 1) if not newval and err == "not found" then log_dict:add("upstream_time-nb", 0) log_dict:incr("upstream_time-nb", 1) end '; } location = /status { content_by_lua ' local log_dict = ngx.shared.log_dict local sum = log_dict:get("upstream_time-sum") local nb = log_dict:get("upstream_time-nb") if nb and sum then ngx.say("average upstream response time: ", sum / nb, " (", nb, " reqs)") else ngx.say("no data yet") end '; } } ``` 该指令在`v0.5.0rc31`版本被首次引入。 [返回目录](#directives) > English source: log_by_lua ---------- **syntax:** *log_by_lua &lt;lua-script-str&gt;* **context:** *http, server, location, location if* **phase:** *log* Run the Lua source code inlined as the `<lua-script-str>` at the `log` request processing phase. This does not replace the current access logs, but runs after. Note that the following API functions are currently disabled within this context: * Output API functions (e.g., [ngx.say](#ngxsay) and [ngx.send_headers](#ngxsend_headers)) * Control API functions (e.g., [ngx.exit](#ngxexit)) * Subrequest API functions (e.g., [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi)) * Cosocket API functions (e.g., [ngx.socket.tcp](#ngxsockettcp) and [ngx.req.socket](#ngxreqsocket)). Here is an example of gathering average data for [$upstream_response_time](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#var_upstream_response_time): ```nginx lua_shared_dict log_dict 5M; server { location / { proxy_pass http://mybackend; log_by_lua ' local log_dict = ngx.shared.log_dict local upstream_time = tonumber(ngx.var.upstream_response_time) local sum = log_dict:get("upstream_time-sum") or 0 sum = sum + upstream_time log_dict:set("upstream_time-sum", sum) local newval, err = log_dict:incr("upstream_time-nb", 1) if not newval and err == "not found" then log_dict:add("upstream_time-nb", 0) log_dict:incr("upstream_time-nb", 1) end '; } location = /status { content_by_lua ' local log_dict = ngx.shared.log_dict local sum = log_dict:get("upstream_time-sum") local nb = log_dict:get("upstream_time-nb") if nb and sum then ngx.say("average upstream response time: ", sum / nb, " (", nb, " reqs)") else ngx.say("no data yet") end '; } } ``` This directive was first introduced in the `v0.5.0rc31` release. [Back to TOC](#directives)