用nginx-lua搭的服務需要寫日志,一般采用nginx自帶的accesslog加logrotate腳本來實現,但是無法滿足一次請求需要寫多條日志的需求
之前用C和GO實現過類似的代碼,思路是主進程寫管道,子進程讀管道並交由apache-rotatelogs寫日志
這裡用Lua也實現了一下--
-- Rlog is an non-blocking logging based on pipe.
-- Rotatelogs of Apache is recommanded to be the output of pipe.
-- Before using Rlog, you should install luaposix.
--
local posix = require("posix")
local os = require("os")
-- input of pipe
local pipe_in
-- init rlog
-- @param pipe_cmd pipe operator and the reveiver command.
-- e.g. "| rotatelogs -l %Y%m%d%H.logfile 3600"
-- @return true when success, false when fail
local function init(pipe_cmd)
-- if already inited, do nothing
if pipe_in then return true end
-- if pipe_cmd is not start with pipe operator, return false
if string.sub(pipe_cmd, 1, 1) ~= "|" then return false end
-- create pipe
local pout, pin = posix.pipe()
-- fork process to execute cmd
if posix.fork() == 0 then
-- close stdin
io.close(io.stdin)
-- set output of pipe as stdin
posix.dup2(pout, posix.fileno(io.stdin))
-- close input and output of pipe
posix.close(pout)
posix.close(pin)
-- execute cmd
os.execute(string.sub(pipe_cmd, 2, -1))
end
-- get input of pipe
pipe_in = pin
-- close output of pipe
posix.close(pout)
return true
end
-- write log
local function log(log_str)
-- write log into pipe
posix.write(pipe_in, log_str .. "\n")
end
return {
init = init,
log = log
}
下邊是它的測試程序
local rlog = require("rlog")
-- init
ret = rlog.init("| rotatelogs -l %Y%m%d%H.log 3600")
if not ret then
print("init fail")
end
-- log
rlog.log("Hello Rlog")
由於posix.write寫管道是原子的,所以無須擔心多進程或多線程寫混亂的問題
不過這段代碼依賴luaposix庫,使用前需要安裝一下。
Lua 語言 15 分鐘快速入門 http://www.linuxidc.com/Linux/2013-06/86582.htm
Lua程序設計(第2版)中文 PDF http://www.linuxidc.com/Linux/2013-03/81833.htm
Lua程序設計(第二版)閱讀筆記 http://www.linuxidc.com/Linux/2013-03/81834.htm
NetBSD 將支持用 Lua 腳本開發內核組件 http://www.linuxidc.com/Linux/2013-02/79527.htm
CentOS 編譯安裝 Lua LuaSocket http://www.linuxidc.com/Linux/2011-08/41105.htm
Programming In Lua 高清PDF中文版 http://www.linuxidc.com/Linux/2015-05/117362.htm
如何配置一套優雅的Lua開發環境 http://www.linuxidc.com/Linux/2015-10/124397.htm
Lua 的詳細介紹:請點這裡
Lua 的下載地址:請點這裡