http://help.directadmin.com/item.php?id=191
If you want to add any extra modules to apache, they'll need to be compiled in. Any module that needs to be compiled in will have a --with-module type flag which will need to be used. To add this flag, run the following:
cd /usr/local/directadmin/customapache
vi configure.apache_ssl
＃将--with-module行添加到文件的末尾，其中--with-module将替换为要安装的模块的必需条目。 查看你的模块文档。
＃并确保该字符存在于除最后一行之外的所有行的末尾。
./build clean
./build apache_mod_ssl
然后重新启动apache：
FreeBSD：
/sbin/service httpd restart
FreeBSD：
/usr/local/etc/rc.d/httpd restart
如果遇到问题，您可能还需要重新编译php：
./build php
然后重新启动apache。
