X-sendfile on Apache

[drola]

Q	A
Bug report?	yes
Feature request?	yes
BC Break report?	no
RFC?	yes
Symfony version	3.3

Description of the problem:
Documentation states that BinaryFileResponse will automatically make use of x-sendfile on Apache and Nginx. However, according to this line it requires presence of X-Sendfile-Type header. This header is not present by just enabling mod_xsendfile on Apache and mod_xsendfile documentation states nothing about configuring Apache to inject that header. This means that BinaryFileResponse will fallback to sending file through PHP for most Apache users even with mod_xsendfile installed and enabled.

Suggested solution:
Detecting configuration of mod_xsendfile on apache doesn't seem to be possible. We need to know whether mod_xsendfile is enabled for specific script and we need to know whether we are trying to send a file from one of whitelisted paths. Apart from presence of mod_xsendfile I cannot see above mentioned details in phpinfo() which means they probably cannot be autodetected.

I propose adding two config options:

xsendfile_header: "X-Sendfile"
xsendfile_whitelist: ["/var/www/static"]

BinaryFileResponse needs to decide whether to use xsendfile based both on the availability of mod_xsendfile and the whitelist.

[kiler129]

@drola Is the mod_xsendfile even supported?

It seems abandoned: https://github.com/nmaier/mod_xsendfile

[drola]

It is still in at least in Ubuntu, Debian and CentOS repositories. It's code is rather short because it just defers handling of the file to httpd's static file handling logic. That might be the reason it didn't need updates in the last 5 years.

Are you considering whether we should just drop mod_xsendfile support from Symfony?

[fabpot]

I don't think we want to fix that one. Let's close.

[mpdude]

Sorry for being late to the party – does that imply Symfony officially dropped mod_xsendfile support for Apache?

[mpdude]

Apache users can enable mod_headers (if not already in use) and add the following to their server configuration:

<IfModule mod_xsendfile.c>
   # You already have this somewhere...
   XSendFile on
   XSendFilePath ...some path...

   # Add this:
   <IfModule mod_headers.c>
      RequestHeader set X-Sendfile-Type X-Sendfile
   </IfModule>
</IfModule>

Additionally, don't forget to add BinaryFileResponse::trustXSendfileTypeHeader(); somewhere in your code before sending the response.