使用 Nginx 的 image_filter 模块来构建动态缩略图服务器

$ nginx -V

# CentOS / RHEL
$ sudo yum -y install gd-devel

# Ubuntu / Debian
$ sudo apt-get install libgd2-xpm-dev

$ sudo wget http://nginx.org/download/nginx-1.15.0.tar.gz
$ sudo tar xzvf nginx-1.15.0.tar.gz
$ cd nginx-1.15.0/
$ sudo ./configure --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-cc-opt='-g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie' --with-http_image_filter_module
$ make && make install

$ nginx -V
nginx version: nginx/1.15.0
built by gcc 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4)
built with OpenSSL 1.0.2g  1 Mar 2016
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-cc-opt='-g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie' --with-http_image_filter_module

# 关闭模块
image_filter off;  

# 确保图片是 JPEG、GIF、PNG、或者 WebP，否则返回 415 错误    
image_filter test;  

# 输出有关图像的 json 格式，例如 { "img" : { "width": 100, "height": 100, "type": "gif" } } ，如果出错显示：{}  
image_filter size;  

# 将图像旋转指定度数，参数可以包括变量。单独或一起与 resize crop 一起使用。  
image_filter rotate 90|180|270;
 
# 按比例减少图像到指定大小，要减少一个维度，可以将另一个维度指定为 "-" 来表示, 出错返回 415 错误。参数值可包含变量，可以与 rotate 一起使用。  
image_filter resize width height;  

# 按比例将图像缩小到较大的一侧，并在另一侧产生无关边缘。其它和 rotate 一样。
image_filter crop width height;

# 设置读取图像缓冲的最大大小，超过则报 415 错误。
image_filter_buffer 10M;
  
# 如果启用，最终图像将交错。对于JPEG，最终图像将采用 "逐行JPEG" 格式。
image_filter_interlace on;

# 设置转换的 JPEG 图像的质量。可接受的值是从 1 到 100 的范围内。较小的值通常意味着图像质量越低，以达到减少数据传输。推荐的最大值为 95，参数值可以包含变量。  
image_filter_jpeg_quality 95;

# 增加最终图像的清晰度，锐度百分比可以超过 100。零值将禁用锐化。参数值可以包含变量。 
image_filter_sharpen 100;
 
# 定义在使用调色板指定的颜色转换 GIF 图像或 PNG 图像时是否应保留透明度。透明度的降低会导致质量更好的图像，PNG 中 的 alpha 通道透明度始终保留。
image_filter_transparency on;

$ sudo vim nginx.conf

...
server {
  listen 80 default_server;
  listen [::]:80 default_server;
  server_name www.hi-linux.com;
 
  location ~ ^/([0-9]+)/(.*)$ {
    set $width $1;
    set $path $2;
    set $EXPIRE_TIME 1d;
    set $JPG_QUALITY 95;
    rewrite ^ /$path break;
    image_filter resize $width -;
    image_filter_buffer 100M;
    image_filter_jpeg_quality ${JPG_QUALITY};
    expires ${EXPIRE_TIME};
  }
}
...

$ sudo nginx -s reload

$ sudo vim nginx.conf
...

proxy_cache_path /data keys_zone=cache_zone:10m;

server {
  # Internal image resizing server.
  server_name localhost;
  listen 8888;

  location ~ ^/([0-9]+)/(.*)$ {
    set $width $1;
    set $path $2;
    set $JPG_QUALITY 95;
    rewrite ^ /$path break;
    #proxy_pass ${IMAGE_HOST};
    image_filter resize $width -;
    image_filter_buffer 100M;
    image_filter_jpeg_quality ${JPG_QUALITY};
  }
}

server {
  listen 80 default_server;
  listen [::]:80 default_server;
  server_name www.hi-linux.com;

  location ~ ^/([0-9]+)/(.*)$ {
    set $width $1;
    set $path $2;
    set $EXPIRE_TIME 1d;
    rewrite ^ /$path break;
    proxy_pass http://127.0.0.1:8888/$width/$path;
    proxy_cache cache_zone;
    proxy_cache_key $uri;
    proxy_cache_valid 200 302 24h;
    proxy_cache_valid 404 1m;
    # expire time for browser
    expires ${EXPIRE_TIME};
  }
}

$ vim docker-compose.yml

version: '2'

services:
  minio:
    image: minio/minio
    container_name: minio
    ports:
      - "9000:9000"
    volumes:
      - minio-data:/data
    environment:
      MINIO_ACCESS_KEY: YOUR_MINIO_ACCESS_KEY
      MINIO_SECRET_KEY: YOUR_MINIO_SECRET_KEY
    command: server /data
 
  image-resizer:
    image: appleboy/nginx-image-resizer
    container_name: image-resizer
    ports:
      - "80:80"
    environment:
      IMAGE_HOST: http://minio:9000
      NGINX_HOST: localhost
 
volumes:
  minio-data:

$ docker-compose up -d