lua-zlib模块安装、使用

妖狐艹你老母 2021-06-22 15:38 624阅读 0赞

github：[https://github.com/brimworks/lua-zlib][https_github.com_brimworks_lua-zlib]

在nginx上对gzip数据进行解压需要使用lua，借助一个库：lua-zlib， lua是一个和C语言结合紧密的脚本语言，实际上lua-zlib就是一个C语言编写的库，我们现在需要做的就是将其编译成一个动态链接库zlib.so，让lua来引用。

注：lua-zlib这个库可以对gzip解压，无法压缩成gzip，只能压缩成deflate。

编译该库时需要lua环境，由于安装了openresty（内置了lua环境），所以无需单独安装lua环境。编译时通过LUA\_INCLUDE\_DIR、LUA\_LIBRARIES指定openresty中的lua路径即可。

**1、安装：**

根据官网说明，需要确认安装zlib、并且需要使用cmake编译。

1.1）检查centos上是否安装zlib：

$ rpm -qa zlib
    zlib-1.2.3-29.el6.x86_64

如果没有，需要先安装zlib。

1.2）安装cmake：

首先检查gcc、g++、make是否安装；

gcc -v
    g++ -v
    make -v

如果没有通过如下命令安装：yum install -y gcc gcc-c++ make automake

然后，安装cmake：

cd /usr/local
    wget http://www.cmake.org/files/v2.8/cmake-2.8.10.2.tar.gz
    tar -xvzf cmake-2.8.10.2.tar.gz
    cd cmake-2.8.10.2
    ./bootstrap
    gmake
    gmake install
    
    检查cmake是否安装成功：
    $ cmake --version
    cmake version 2.8.10.2

1.3）lua-zlib安装：

1）下载：

cd /usr/local
    wget https://github.com/brimworks/lua-zlib/archive/master.zip
    unzip lua-zlib-master.zip

2）编译：

cd /usr/local/lua-zlib-master
    cmake -DLUA_INCLUDE_DIR=/usr/local/openresty/luajit/include/luajit-2.1 -DLUA_LIBRARIES=/usr/local/openresty/luajit/lib -DUSE_LUAJIT=ON -DUSE_LUA=OFF

注：编译时指定openresty中的lua环境

make
    cp zlib.so /usr/local/openresty/lualib/zlib.so

参考：[https://www.bbsmax.com/A/1O5E8PnbJ7/][https_www.bbsmax.com_A_1O5E8PnbJ7]

[https://groups.google.com/forum/\#!topic/openresty/MrBCqVn19lE][https_groups.google.com_forum_topic_openresty_MrBCqVn19lE]

**2、使用lua-zlib：**

2.1）在lua脚本中使用：

更多示例可以参考github。

local src_dir, build_dir = ...
    src_dir = src_dir or "./"
    build_dir = build_dir or "/usr/local/openresty/lualib/"
    package.path  = src_dir .. "?.lua;" .. package.path
    package.cpath = build_dir .. "?.so;" .. package.cpath
    
    local lz    = require("zlib")
    
    local test_string = "aaaaaaaaaaaaaaaaa"
    --压缩
    local deflated = lz.deflate()(test_string, "finish")
    print(deflated)
    
    --解压
    local inflated = lz.inflate()(deflated, "finish")
    print(inflated)

运行

$ lua test.lua 
    xKLD 
    aaaaaaaaaaaaaaaaa

2.2）在openresty中使用lua-zlib：

worker_processes  8;
    
    events {
        worker_connections  1024;
    }
    
    http {
        include       mime.types;
        default_type  text/html;
    
        log_format  main  '$remote_addr [$time_local] "$request" '
                          '"$http_x_forwarded_for"';
    
        access_log  /data/logs/nginx/access.log  main;
        error_log   /data/logs/nginx/error.log warn;
        underscores_in_headers on;
        server {
            listen       80;
            server_name  localhost;
            access_log  /data/logs/nginx/access.log  main;
    
            location /test {
              echo "hello, world!";
              content_by_lua '
                local zlib = require "zlib"
    	    local stream = zlib.deflate()("123456","finish")
                ngx.say(stream)
    	  ';
            }
        }
    }

注：在openresty中遇到的问题：

guard:12: writing a global lua variable ('zlib') which may lead to race conditions between concurrent requests, so prefer the use of 'local' variables

解答：[https://github.com/openresty/openresty/issues/510][https_github.com_openresty_openresty_issues_510]

[https_github.com_brimworks_lua-zlib]: https://github.com/brimworks/lua-zlib
[https_www.bbsmax.com_A_1O5E8PnbJ7]: https://www.bbsmax.com/A/1O5E8PnbJ7/
[https_groups.google.com_forum_topic_openresty_MrBCqVn19lE]: https://groups.google.com/forum/#!topic/openresty/MrBCqVn19lE
[https_github.com_openresty_openresty_issues_510]: https://github.com/openresty/openresty/issues/510