Apache won't follow symlinks (403 Forbidden)

问题:

I'm having some trouble setting up Apache on Ubuntu. I've been following this guide.

# /usr/sbin/apache2 -v
Server version: Apache/2.2.17 (Ubuntu)
Server built:   Feb 22 2011 18:33:02

My public directory, /var/www, can successfully serve up and execute PHP pages that are placed in it. However, I want to create a symlink in /var/www that points to a directory in my home folder and serve pages there.

[root /var/www]# ll
total 36
drwxr-xr-x  3 root root 4096 2011-09-11 14:22 .
drwxr-xr-x 14 root root 4096 2011-06-04 22:49 ..
lrwxrwxrwx  1 root root   16 2011-09-11 13:21 about -> /root/site/about

When I try to access /about on browser, I get

Forbidden

You don't have permission to access /about on this server.

As far as I know, I gave sufficient privileges to the files I want to serve:

[root ~/site/about]# ll
total 24
drwxr-xr-x 5 root root 4096 2011-09-11 13:20 .
drwxr--r-- 3 root root 4096 2011-09-11 13:19 ..
drwxr-xr-x 2 root root 4096 2011-09-11 13:21 contact
-rwxr-xr-x 1 root root 1090 2011-09-11 13:19 index.php
drwxr-xr-x 2 root root 4096 2011-09-11 13:20 me
drwxr-xr-x 2 root root 4096 2011-09-11 13:21 resume

I'm aware of the FollowSymLinks option, and I believe it's set in my /etc/apache2/sites-enabled/000-default file:

DocumentRoot /var/www
<Directory />
    Options FollowSymLinks
    AllowOverride None
</Directory>
<Directory /var/www/>
    Options FollowSymLinks Indexes MultiViews
    AllowOverride None
    Order allow,deny
    allow from all
</Directory>

Any idea what I could be missing?

回答1:

Check that Apache has execute rights for /root, /root/site and /root/site/about.

Run:

chmod o+x /root /root/site /root/site/about

回答2:

The 403 error may also be caused by an encrypted file system, e.g. a symlink to an encrypted home folder.

If your symlink points into the encrypted folder, the apache user (e.g. www-data) cannot access the contents, even if apache and file/folder permissions are set correctly. Access of the www-data user can be tested with such a call:

sudo -u www-data ls -l /var/www/html/<your symlink>/

There are workarounds/solutions to this, e.g. adding the www-data user to your private group (exposes the encrypted data to the web user) or by setting up an unencrypted rsynced folder (probably rather secure). I for myself will probably go for an rsync solution during development.

https://askubuntu.com/questions/633625/public-folder-in-an-encrypted-home-directory

A convenient tool for my purposes is lsyncd. This allows me to work directly in my encrypted home folder and being able to see changes almost instantly in the apache web page. The synchronization is triggered by changes in the file system, calling an rsync. As I'm only working on rather small web pages and scripts, the syncing is very fast. I decided to use a short delay of 1 second before the rsync is started, even though it is possible to set a delay of 0 seconds.

Installing lsyncd (in Ubuntu):

sudo apt-get install lsyncd

Starting the background service:

lsyncd -delay 1 -rsync /home/<me>/<work folder>/ /var/www/html/<web folder>/

回答3:

I was having a similar problem that I could not resolve for a long time on my new server. In addition to palacsint's answer, a good question to ask is: are you using Apache 2.4? In Apache 2.4 there is a different mechanism for setting the permissions that do not work when done using the above configuration, so I used the solution explained in this blog post.

Basically, what I needed to do was convert my config file from:

Alias /demo /usr/demo/html

<Directory "/usr/demo/html">
    Options FollowSymLinks
    AllowOverride None
    Order allow,deny
    allow from all

</Directory>

to:

Alias /demo /usr/demo/html

<Directory "/usr/demo/html">
    Options FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

Note how the Order and allow lines have been replaced by Require all granted

回答4:

Related to this question, I just figured out why my vhost was giving me that 403.

I had tested ALL possibilities on this question and others without luck. It almost drives me mad.

I am setting up a server with releases deployment similar to Capistrano way through symlinks and when I tried to access the DocRoot folder (which is now a symlink to current release folder) it gave me the 403.

My vhost is:

DocumentRoot /var/www/site.com/html
<Directory /var/www/site.com/html>
        AllowOverride All
        Options +FollowSymLinks
        Require all granted
</Directory>

and my main httpd.conf file was (default Apache 2.4 install):

DocumentRoot "/var/www"
<Directory "/var/www">
    Options -Indexes -FollowSymLinks -Includes
(...)

It turns out that the main Options definition was taking precedence over my vhosts fiel (for me that is counter intuitive). So I've changed it to:

DocumentRoot "/var/www"
<Directory "/var/www">
    Options -Indexes +FollowSymLinks -Includes
(...)

and Eureka! (note the plus sign before FollowSymLinks in MAIN httpd.conf file. Hope this help some other lost soul.

回答5:

For anyone having trouble after upgrading to 14.04 https://askubuntu.com/questions/452042/why-is-my-apache-not-working-after-upgrading-to-ubuntu-14-04 as root changed before upgrade = /var/www after upgrade = /var/www/html

回答6:

There is another way that symbolic links may fail you, as I discovered in my situation. If you have an SELinux system as the server and the symbolic links point to an NFS-mounted folder (other file systems may yield similar symptoms), httpd may see the wrong contexts and refuse to serve the contents of the target folders.

In my case the SELinux context of /var/www/html (which you can obtain with ls -Z) is unconfined_u:object_r:httpd_sys_content_t:s0. The symbolic links in /var/www/html will have the same context, but their target's context, being an NFS-mounted folder, are system_u:object_r:nfs_t:s0.

The solution is to add fscontext=unconfined_u:object_r:httpd_sys_content_t:s0 to the mount options (e.g. # mount -t nfs -o v3,fscontext=unconfined_u:object_r:httpd_sys_content_t:s0 <IP address>:/<server path> /<mount point>). rootcontext is irrelevant and defcontext is rejected by NFS. I did not try context by itself.

回答7:

First disable selinux (vim /etc/selinux/config)

vim /etc/httpd/conf/httpd.conf edit following lines for symlinks and directory indexing:

documentroot /var/www/html
<directory /var/www/html>
    Options Indexes FollowSymLinks
    AllowOverride None
</directory>

If .htaccess file then AllowOverride all