1.产生的背景
随着互联网的快速发展、需求频繁变更、内容数量的俱增、时间的持续增长,图片数量也会越来越多。在实际需求中,会出现在若干个页面或同一个页面不同位置,展示同一条信息以及其缩略图。在这时,如果使用 CSS 控制图片显示的大小,对于那些与该位置不成比例的图片,缩小后就会出现图片变形。也不可能让编辑人员,对所有的图片进行 PS,这时候就产生了强烈的自动化裁剪、缩放图片的需求,来适应不同规格的缩略图。
Nginx 虽然有自带的 image filter module 也能实现此功能,但是有弊端:
image filter module 使用的是 GD,GD 性能、效率、处理后的图片质量不如 GraphicsMagick
image filter module 没法真正生成裁剪/缩放后的图片,而是通过 Nginx 直接输出的,这样每次请求或缓存过期后都需要重新裁剪/缩放,这样无疑会增加 Nginx 负担
2.准备安装的软件
操作系统是:centos7 linux
Tengine:https://github.com/alibaba/tengine
详细过程如图:
Lua:http://www.lua.org/download.html
LuaJIT:http://luajit.org/download.html
所需的依赖包:
libjpeg、libjpeg-devel
libpng、libpng-devel
giflib、giflib-devel
freetype、freetype-devel
GraphicsMagick:http://sourceforge.net/projects/graphicsmagick/files/graphicsmagick/
3.安装软件
3.1Lua的安装
注意:readline&readline-devel(Lua 所需)
# yum install readline
# yum install readline-devel
详细的安装步骤,请参考: centos7下安装lua-5.3.4
3.2LuaJIT的安装
下载、解压、编译
$ wget http://luajit.org/download/LuaJIT-2.0.5.tar.gz
$ tar -xzf LuaJIT-2.0.5.tar.gz
//切换到root用户下执行编译
# make && make install
出现如图所示,证明成功:
3.3Tengine的安装
解压、安装命令如下:
$ wget http://tengine.taobao.org/download/tengine-2.2.0.tar.gz
$ tar -xzf tengine-2.2.0.tar.gz
进入 Tengine 源码目录
$ cd tengine-2.2.0$ ./configure --prefix=/usr/local/tengine --dso-path=/usr/local/tengine/modules --with-http_realip_module --with-http_gzip_static_module --with-http_stub_status_module --with-http_concat_module --with-http_lua_module --http-proxy-temp-path=/var/tmp/Tengine/proxy_temp --http-fastcgi-temp-path=/var/tmp/Tengine/fastcgi_temp --http-uwsgi-temp-path=/var/tmp/Tengine/uwsgi_temp --http-scgi-temp-path=/var/tmp/Tengine/cgi_temp --http-client-body-temp-path=/var/tmp/Tengine/client_body_temp --http-log-path=/var/log/Tengine/access.log --error-log-path=/var/log/Tengine/error.log
切换到root用户,执行编译
# make && make install
如果报有下面错误:
src/http/modules/lua/ngx_http_lua_log.c: 在函数‘ngx_http_lua_ngx_log’中:
src/http/modules/lua/ngx_http_lua_log.c:40: 错误:‘LUA_GLOBALSINDEX’未声明(在此函数内第一次使用)
src/http/modules/lua/ngx_http_lua_log.c:40: 错误:(即使在一个函数内多次出现,每个未声明的标识符在其
src/http/modules/lua/ngx_http_lua_log.c:40: 错误:所在的函数内也只报告一次。)
src/http/modules/lua/ngx_http_lua_log.c: 在函数‘ngx_http_lua_print’中:
src/http/modules/lua/ngx_http_lua_log.c:81: 错误:‘LUA_GLOBALSINDEX’未声明(在此函数内第一次使用)
时,是因为使用了不兼容的 Lua 的头文件,configure 需要加上
--with-ld-opt="-Wl,-rpath,$LUAJIT_LIB"
或者
--with-luajit-inc=PATH set LuaJIT headers path (where lua.h/lauxlib.h/... are located)
--with-luajit-lib=PATH set LuaJIT library path (where libluajit-5.1.{a,so} are located)
如果在启动或者执行 Tengine 任意命令时,出现以下错误,那么就是,无法找到动态库 libluajit-5.1.so.2 ,64位系统貌似是去 /lib64 目录中寻找动态库的。
那么解决办法就是,将 /usr/local/lib/libluajit-5.1.so.2 软连接到 /lib64 目录下:
ln -s /usr/local/lib/libluajit-5.1.so.2 /lib64/libluajit-5.1.so.2
3.4安装依赖
yum -y install libjpeg libjpeg-devel libpng libpng-devel giflib giflib-devel freetype freetype-devel
3.5GraphicsMagick的安装
下载、解压
$ wget https://sourceforge.net/projects/graphicsmagick/files/graphicsmagick/1.3.26/GraphicsMagick-1.3.26.tar.gz/download
$ tar -xzf GraphicsMagick-1.3.26.tar.gz
进入 Tengine 源码目录,指定安装路径
$ cd GraphicsMagick-1.3.26
$ ./configure --prefix=/usr/local/gm --enable-shared
切换到root用户编译安装
# make && make install
在root用户下执行:cd /usr/local/gm/bin/
执行
# ./gm version
看到如下图所示,证明安装成功
4. 修改tengine配置文件
在root用户下执行:
# cd /usr/local/tengine/conf/
# cp nginx.conf nginx.conf.bak
# cd nginx.conf
修改nginx.conf文件
#user nobody;
user root;
worker_processes 1;#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;#pid logs/nginx.pid;events {worker_connections 1024;
}# load modules compiled as Dynamic Shared Object (DSO)
#
#dso {
# load ngx_http_fastcgi_module.so;
# load ngx_http_rewrite_module.so;
#}http {include mime.types;default_type application/octet-stream;#log_format main '$remote_addr - $remote_user [$time_local] "$request" '# '$status $body_bytes_sent "$http_referer" '# '"$http_user_agent" "$http_x_forwarded_for"';#access_log logs/access.log main;sendfile on;#tcp_nopush on;#keepalive_timeout 0;keepalive_timeout 65;#gzip on;server {listen 80;server_name localhost;#charset koi8-r;#access_log logs/host.access.log main;location / {root /home/hadoop/images;index index.html index.htm;}location /lua/ {default_type 'text/html';content_by_lua 'ngx.say("<h1>hello, ttlsa lua</h1>")';}location ~* ^(.+\.(jpg|jpeg|gif|png))_(\d+)x(\d+)\.(jpg|jpeg|gif|png)$ {root /home/hadoop/images; if (!-f $request_filename) { lua_code_cache off; set $request_filepath /home/hadoop/images/$1; set $width $3; set $height $4; set $ext $5; content_by_lua_file /usr/local/tengine/lua/ImageResizer.lua;}} #error_page 404 /404.html;# redirect server error pages to the static page /50x.html#error_page 500 502 503 504 /50x.html;location = /50x.html {root html;}# proxy the PHP scripts to Apache listening on 127.0.0.1:80##location ~ \.php$ {
# proxy_pass http://127.0.0.1;#}# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000##location ~ \.php$ {
# root html;# fastcgi_pass 127.0.0.1:9000;# fastcgi_index index.php;# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;# include fastcgi_params;#}# deny access to .htaccess files, if Apache's document root# concurs with nginx's one##location ~ /\.ht {
# deny all;#}}# another virtual host using mix of IP-, name-, and port-based configuration##server {
# listen 8000;# listen somename:8080;# server_name somename alias another.alias;# location / {
# root html;# index index.html index.htm;# }#}# HTTPS server##server {
# listen 443 ssl;# server_name localhost;# ssl_certificate cert.pem;# ssl_certificate_key cert.key;# ssl_session_cache shared:SSL:1m;# ssl_session_timeout 5m;# ssl_ciphers HIGH:!aNULL:!MD5;# ssl_prefer_server_ciphers on;# location / {
# root html;# index index.html index.htm;# }#}}
修改之处如下图所示:
5.编译脚本
在root用户下,执行
# cd /usr/local/tengine/
# mkdir lua
# cd lua/
# vi ImageResizer.lua
在ImageResizer.lua文件里添加
local command = "/usr/local/gm/bin/gm convert " .. ngx.var.request_filepath .. " -resize " .. ngx.var.width .. "x" .. ngx.var.height .. " +profile \"*\" " .. ngx.var.request_filepath .. "_" .. ngx.var.width .. "x" .. ngx.var.height .. "." .. ngx.var.ext;
os.execute(command);
ngx.exec(ngx.var.request_uri);
6.测试脚本
# cd /usr/local/tengine/sbin/
# ./nginx
第一次启动会出现,如下的错误:
nginx: [emerg] mkdir() "/var/tmp/Tengine/client_body_temp" failed (2: No such file or directory)
解决的办法:
# mkdir -p /var/tmp/Tengine/client_body_temp
筛选当前正在执行nginx的进程: ps -aux | grep nginx
# ./nginx -t #查看编译是否成功
# ./nginx -s reload #重启nginx
在WEB浏览器上输入自己的IP+你图片的名字,效果如下:
设置自己图片的大小后的效果:
笔者推荐链接:
http://blog.csdn.net/xiaolang85/article/details/41675315
https://my.oschina.net/eduosi/blog/169606
http://www.ttlsa.com/nginx/nginx-modules-ngx_lua/
https://my.oschina.net/eduosi/blog/169606