Fixing 403 Forbidden Nginx Errors

1
(No Transcript)
2
Fixing 403 Forbidden Nginx Errors

• HTTP errors are pesky and typically hard to
  resolve without the right tools.
• However, with proper investigation and tools, you
  can easily identify the source of a problem and
  fix it just as fast.
• In order to debug or fix 403 Forbidden Nginx
  errors, all you have to do is check the correct
  error logs and take the proper action to resolve
  it.
• Well go over how to check the error logs and the
  possible scenarios that typically cause these
  errors.

3
Fixing 403 Forbidden Nginx Errors

• Finding Error Logs
• If you know exactly where the error logs of your
  Nginx server are, you can skip onto the next
  section.
• If youre not sure where to find the error logs
  of your Nginx server, then be sure to continue
  this section.
• The path for error logs can change a lot
  depending on how Nginx was installed on the
  server and the Linux distribution.
• If you do not know where your error logs are and
  you have a hard time going through Nginx
  configuration, we can use a very small and useful
  Linux tool with the name of lsof which gives us
  all the open files associated to a specific
  process.
• This will help us find the error log for your web
  server.

4
Fixing 403 Forbidden Nginx Errors

• The first step of this is to check for the
  process ID of the main Nginx process, you can run
  the following command and except output somewhat
  similar to the one indicated below
• ps x grep nginx 29229 ? S 000 nginx
  master process /usr/sbin/nginx
• The first column of each row is the process ID,
  as we can see, the main/master process ID
  is 29229 in this case, however this will change
  in every system.
• Once you have the process ID, you will be able to
  use the lsof too to get all open files associated
  to this process by running the following.
• Weve trimmed the output to the part you should
  be looking for, as there might be a lot more data
  when you run that command

5
Fixing 403 Forbidden Nginx Errors

• As you can see from the above output, we can see
  that one of the files that are open by this Nginx
  installation is /var/log/nginx/error.log which
  (by the file name) does look like an error log.
• Weve now identified the path of our Nginx error
  log and we can move onto finding the reason
  behind our pesky HTTP error.

6
Fixing 403 Forbidden Nginx Errors

• Fixing Nginx HTTP errors
• Once you have the correct error log file, its
  time to watch for errors.
• In our experience, the best way to do this is by
  running a continuous stream of the error log in
  your shell screen using the tail utility.
• tail -f /var/log/nginx/error.log
• Once youve ran this command, tail will
  continuously output any newly appended content to
  the error.log as it comes in until you
  hit Control C.
• We recommend that you clear the entire shell
  screen to make it easy to identify newly appended
  content.
• You can do this in Windows (PuTTY) by right
  clicking the PuTTY menu bar and clicking on
  Clear Scrollback or on Mac OS X by
  clicking Command K.

7
Fixing 403 Forbidden Nginx Errors

• Now, you will need to replicate the issue that
  you are getting.
• The error should be printed out right away after
  you replicate the issue.
• For example, if you have a 403 Forbidden error,
  then you should refresh the page that is causing
  the problem so that a new error log entry can be
  appended.
• Once that is done, youll see a new line in the
  error log which should hopefully lead you to the
  right path to fixing the issue.
• Were going to cover a few of the most common
  issues below.

8
Fixing 403 Forbidden Nginx Errors

• Incorrect Directory Settings
• The error below can be caused by two different
  reasons incorrect directory index or disallowed
  directory listing.
• 2013/08/31 150343 error 292310 2098806
  directory index of "/usr/share/nginx/static/" is
  forbidden, client 1.1.1.1, server domain.com,
  request "GET / HTTP/1.1", host "domain.com
• If you are trying to list all the files in a
  folder, you will get that error if the directory
  does not have directory listing enabled.
• You can enable directory listing by adding the
  following line to your Nginx configuration, you
  can read more about this option
  here http//nginx.org/en/docs/http/ngx_http_autoi
  ndex_module.html
• autoindex on

9
Fixing 403 Forbidden Nginx Errors

• The other possibility for that error to come up
  is if your index setting is incorrect, so for
  example, you have a index.php file in that
  folder, however, your index setting is setup
  to index.htm and index.html.
• This means that only these files are checked if
  no specific file is provided.
• If you alter it to something like the following,
  your index.php file should work
• index index.htm index.html index.php

10
Fixing 403 Forbidden Nginx Errors

• Incorrect Permissions
• The error below is generally caused by incorrect
  Unix permissions, you will need to make sure you
  have the correct permissions for the entire path.
• 2013/09/01 003157 error 292310 2115270
  open() "/usr/share/nginx/static/forbidden" failed
  (13 Permission denied), client 1.1.1.1,
  server domain.com, request "GET /forbidden
  HTTP/1.1", host "domain.com
• As you see, the file that we are trying to access
  is /usr/share/nginx/static/forbidden.
• In order for Nginx to access it with no problems
  at all, Nginx must have read permissions for that
  specific file as well as execute for all the
  folders above it.
• This means that /, /usr, /usr/share, /usr/share/ng
  inx and /usr/share/nginx/static must be
  executable by Nginx and the file /usr/share/nginx/
  static/forbidden must be readable by Nginx in
  this case.

11
Fixing 403 Forbidden Nginx Errors

• Conclusion
• Weve gone through quite a few tools such
  as tail and lsof.
• These are just one of the tools which are offered
  by Linux which allow system administrators to
  resolve and debug issues much faster and easier.
• The most important factor in resolving system
  issues is being able to identify the issue
  properly, resolution is usually the easiest part
  once the problem is identified.
• The larger the toolset of the system
  administrator, the faster they can identify and
  fix those problems.