Apache httpd 2.4 反向代理不压缩

Question

使用 Apache httpd 2.2，可以设置反向代理并使用 mod_deflate 来压缩代理内容，遵循 Accept-Encoding: gzip header 。

此配置足以使其正常工作:

    LoadModule deflate_module modules/mod_deflate.so
    LoadModule filter_module modules/mod_filter.so
    SetOutputFilter DEFLATE

    LoadModule proxy_module modules/mod_proxy.so
    LoadModule proxy_http_module modules/mod_proxy_http.so
    ProxyRequests Off
    ProxyPass        /tomcat http://localhost:8880/
    ProxyPassReverse /tomcat http://localhost:8880/
    ProxyPass        /other  http://localhost:8001/
    ProxyPassReverse /other  http://localhost:8001/

现在升级到 2.4(Windows 上为 2.4.29)后，接受相同的配置，并且它确实压缩了 DocumentRoot 提供的静态内容。但当通过 ProxyPass 检索时，会返回未压缩的相同内容。

我知道我可以配置 Tomcat 来进行压缩，但还有另一个服务器只是忽略 Accept-Encoding header 。

如何设置反向代理并压缩代理内容？

编辑:

以下是返回的 header ，表明代理内容未被 2.4 服务器压缩:

----- Retrieving uncompressed from DocumentRoot ---------------------------------

C:\Temp>curl -I http://localhost/test.txt 
HTTP/1.1 200 OK
Date: Tue, 09 Jan 2018 17:11:59 GMT
Server: Apache/2.4.29 (Win64) OpenSSL/1.1.0g
Last-Modified: Fri, 05 Jan 2018 12:58:40 GMT
ETag: "75441-5620701eb471c"
Accept-Ranges: bytes
Content-Length: 480321
Vary: Accept-Encoding
Content-Type: text/plain

----- The same from Tomcat ------------------------------------------------------

C:\Temp>curl -I http://localhost:8880/rr/test.txt 
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"480321-1515157120042"
Last-Modified: Fri, 05 Jan 2018 12:58:40 GMT
Content-Type: text/plain
Content-Length: 480321
Date: Tue, 09 Jan 2018 17:11:59 GMT

----- 2.4.29: Retrieving compressed from DocumentRoot ---------------------------

C:\Temp>curl -I -H "Accept-Encoding: gzip" http://localhost/test.txt 
HTTP/1.1 200 OK
Date: Tue, 09 Jan 2018 17:11:59 GMT
Server: Apache/2.4.29 (Win64) OpenSSL/1.1.0g
Last-Modified: Fri, 05 Jan 2018 12:58:40 GMT
ETag: "75441-5620701eb471c-gzip"
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 48265
Content-Type: text/plain

----- 2.4.29: Not getting any compression for proxied Tomcat content ------------

C:\Temp>curl -I -H "Accept-Encoding: gzip" http://localhost/tomcat/rr/test.txt 
HTTP/1.1 200 OK
Date: Tue, 09 Jan 2018 17:11:59 GMT
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"480321-1515157120042"
Last-Modified: Fri, 05 Jan 2018 12:58:40 GMT
Content-Type: text/plain
Content-Length: 480321

----- 2.2.14: Retrieving compressed from DocumentRoot ---------------------------

C:\Temp>curl -I -H "Accept-Encoding: gzip" http://localhost:81/test.txt 
HTTP/1.1 200 OK
Date: Tue, 09 Jan 2018 17:11:59 GMT
Server: Apache/2.2.14 (Win32)
Last-Modified: Fri, 05 Jan 2018 12:58:40 GMT
ETag: "90000000e7463-75441-5620701eb471c"
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 48265
Content-Type: text/plain

----- 2.2.14: Proxied Tomcat content comes compressed ---------------------------

C:\Temp>curl -I -H "Accept-Encoding: gzip" http://localhost:81/tomcat/rr/test.txt 
HTTP/1.1 200 OK
Date: Tue, 09 Jan 2018 17:11:59 GMT
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"480321-1515157120042"
Last-Modified: Fri, 05 Jan 2018 12:58:40 GMT
Content-Type: text/plain
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 20

所有这些都是在从 ApacheHaus 下载的普通 2.4.29 安装上进行测试的。 。上述配置已添加到httpd.conf中，其他没有改变。这同样适用于 2.2.14 安装(2009 年从 Apache 下载)，但该版本另外更改为端口 81。

Answer 1

我已经成功重现了您描述的 curl + apache/tomcat 行为

这就是我复制它的方式(OS X El Capitan):

Tomcat :

docker run -it --rm -p 8880:8080 tomcat:6.0

Apache

httpd -v

Server version: Apache/2.4.18 (Unix)
Server built:   Feb 20 2016 20:03:19

httpd -l
Compiled in modules:
  core.c
  mod_so.c
  http_core.c
  prefork.c

Apache 配置(完整):

Listen 80                                                                       

LoadModule authz_user_module libexec/apache2/mod_authz_user.so                  
LoadModule authz_core_module libexec/apache2/mod_authz_core.so                  
LoadModule access_compat_module libexec/apache2/mod_access_compat.so            
LoadModule filter_module libexec/apache2/mod_filter.so                          
LoadModule deflate_module libexec/apache2/mod_deflate.so                        
LoadModule mime_module libexec/apache2/mod_mime.so                              
LoadModule log_config_module libexec/apache2/mod_log_config.so                  
LoadModule headers_module libexec/apache2/mod_headers.so                        
LoadModule version_module libexec/apache2/mod_version.so                        
LoadModule proxy_module libexec/apache2/mod_proxy.so                            
LoadModule proxy_http_module libexec/apache2/mod_proxy_http.so                  
LoadModule unixd_module libexec/apache2/mod_unixd.so                            

<IfModule unixd_module>                                                         
User _www                                                                       
Group _www                                                                      

</IfModule>                                                                     

<IfModule mime_module>                                                          
    TypesConfig /private/etc/apache2/mime.types                                 
</IfModule>                                                                     

LogLevel debug                                                                  

<IfModule log_config_module>                                                    
    LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
    LogFormat "%h %l %u %t \"%r\" %>s %b" common                                

    <IfModule logio_module>                                                     
      # You need to enable mod_logio.c to use %I and %O                         
      LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio
    </IfModule>                                                                 
    CustomLog "/private/var/log/apache2/access_log" common                      
</IfModule>                                                                     

ErrorLog "/private/var/log/apache2/error_log"                                   
TraceEnable off                                                                 

SetOutputFilter  DEFLATE                                                        

ProxyRequests    Off                                                            
ProxyPass        /tomcat http://localhost:8880/                                 
ProxyPassReverse /tomcat http://localhost:8880/                                 
ProxyPass        /other  http://localhost:8001/                                 
ProxyPassReverse /other  http://localhost:8001/                                 
DocumentRoot    /Library/WebServer/Documents 

检查

curl -I -H 'Accept-Encoding: gzip'  'http://localhost/tomcat' 
HTTP/1.1 200 OK
Date: Sat, 13 Jan 2018 13:35:14 GMT
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"7454-1491118183000"
Last-Modified: Sun, 02 Apr 2017 07:29:43 GMT
Content-Type: text/html
Content-Length: 7454

curl -I -H 'Accept-Encoding: gzip'  'http://localhost/index.html.en' 
HTTP/1.1 200 OK
Date: Sat, 13 Jan 2018 13:35:25 GMT
Server: Apache/2.4.18 (Unix)
Last-Modified: Tue, 09 Jan 2018 04:51:20 GMT
ETag: "45-56250aa712200-gzip"
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 65
Content-Type: text/html

如您所见，输出与您的示例非常匹配

这是有趣的部分

如果我使用常规的GET请求而不是HEAD(通过浏览器或不带-I的curl) tomcat 的响应确实被压缩了

curl -D - -H 'Accept-Encoding: gzip'  'http://localhost/tomcat' 2>/dev/null | strings
HTTP/1.1 200 OK
Date: Sat, 13 Jan 2018 13:37:19 GMT
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"7454-1491118183000-gzip"
Last-Modified: Sun, 02 Apr 2017 07:29:43 GMT
Content-Type: text/html
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 2526
(some junk)

不知道为什么会发生这种情况，看起来像是 Apache 在 HEAD 请求上的 + mod_proxy/defate 错误行为。如果你说它在 Apache 2.2 中没问题，我猜它可能与此 adjustment 有某种关系。

mod_deflate will now skip compression if it knows that the size overhead added by the compression is larger than the data to be compressed.

因此，我会检查您的情况下 GET 请求的问题是否仍然存在。如果是 - 提供有关您的设置的更多详细信息，以便您的环境可以 100% 复制 - 用于 apache 和 tomcat 的有效 Dockerfile 来隔离可能的环境差异就可以了