Configure Apache to serve attachments

[Ryan J Ollos]

The following are excerpts from an email discussion that took place after upgrading to Trac 1.0.

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I previously mentioned the problem with attachments not having been migrated from the $TRACENV/attachments directory to $TRACENV/files/attachments. After re-running one of the database upgrade steps, the attachments were still not displaying, however from what I saw in the logs with the log level set to debug, it seemed like Trac was serving up the file, and there was something wrong with the Apache configuration. Further evidence was that Trac no longer displayed a TracError when attempting to navigate to an attachment, rather it displayed an image of a broken attachment link.

With Trac 1.0, the attachment, th:attachment/wiki/BookmarkPlugin/bookmarkpage.jpg

is now stored at,

$TRACENV/files/attachments/wiki/819/819ffdd855b12bca022d5a9f4e1b75ea2f91b067/4baf82047b92bfcc6bde2217dfc158ead669a4c2.jpg

So I started poking around at the Apache configuration, and seem to have it working with the following change:

trac-hacks-010

@@ -27 +27 @@
 Alias  /chrome/common  /path/to/www/htdocs/common
 Alias  /chrome/site    /path/to/www/htdocs/site
 Alias  /errorpages     /path/to/www/errorpages
-Alias  /raw-attachment /path/to/trac/attachments/
+# Alias        /raw-attachment /path/to/trac/files/attachments/
 
 # use mod_rewrite to let Apache handle 0.10-style requests for
 # raw attachments
 RewriteEngine  On
 RewriteCond    %{QUERY_STRING} ^format=raw$
-RewriteRule    ^/attachment/(.*) /path/to/trac/attachments/$1 [L]
+RewriteRule    ^/attachment/(.*) /path/to/trac/files/attachments/$1 [L]
 
 <Directory     /path/to/www/htdocs>
        Options         -Indexes
        Order           allow,deny
        Allow           from all
 </Directory>
-<Directory     /path/to/trac/attachments>
+<Directory     /path/to/trac/files/attachments>
        Options         -Indexes
        Order           allow,deny
        Allow           from all

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This is a side-effect of the new storage scheme for attachments, and due to the cryptic naming, mapping them through apache is no longer an option. As far as I can tell there is no way we can keep any of the config rules that point to attachments on disk, and these should be removed.

I complained about this some time ago: ​trac:comment:25:ticket:10313

But since that time another good solution has been implemented instead: ​trac:#7894

So install & enable mod_xsendfile seems to be the proper fix for this for Trac 1.0+.

[Ryan J Ollos]

Debian 7 has mod-sendfile 0.9, so the following configuration is used:

XSendFile on
XSendFileAllowAbove On

We could use some brief Trac documentation on configuring mod_xsendfile. I'll add that soon.

[Ryan J Ollos]

Debian 8 has mod-sendfile 0.12 and Apache 2.4., so the following configuration is used:

XSendFile on
XSendFilePath /path/to/trac/env/files/attachments