Is there a way to check if a directory exists in Apache configuration files?

Is there a way to include configuration settings in Apache based on if a directory exists? Basically I have a portable hard drive that I transport between work and home that has some stuff I'm developing on it. I 开发者_JAVA技巧only want the Apache config to load a particular virtual host if the folder exists.

Since Apache 2.4.34 you can now use <IfFile>...</IfFile> which will check to see if a file exists. There's more details on the <IfFile> page.

No, there seems to be no direct way to do this.

The only thing that might be a solution is the IfDefine directive. You can define defines using the -d parameter to when the server is started.

The parameter-name argument is a define as given on the httpd command line via -Dparameter-, at the time the server was started.

You might be able to check for the existence of a directory in a batch or bash file, and set the -d parameter accordingly.

Whether that is an option, will depend on how your server is started from the portable hard drive.

I've come up with a solution that seems to work for Linux and OS X, and it hinges on "mountpoints". It might be possible to emulate it within Windows, as well, but you would probably have to get creative with FUSE and/or Cygwin.

If you create an empty folder in your home directory, such as "/Users/username/ExtraVhosts", you can add an apache directive to "Include /Users/username/ExtraVhosts/*".

Then, when you insert your thumb drive, you can mount somewhere and then use mountpoint "binding" to cross-link the ExtraVhosts folder to a folder on the mobile device.

An OS X example:

• I have a thumb drive called 'Cherrybomb'
• When I insert it, it always gets mounted to /Volumes/Cherrybomb
• I can then use bindfs (sudo port install bindfs) to mount a subfolder of it, like so:
  • sudo bindfs /Volumes/Cherrybomb/Projects/vhosts /Users/username/ExtraVhosts
• Then I can restart apache to read in the updated configuration:
  • sudo /opt/local/apache2/bin/apachectl restart

At that point, it's just a matter of adding entries in /etc/hosts for server aliases to get picked up.

The linux equivalent would be using the "--bind" parameter of the mount command.

One caveat: This makes it difficult to quickly unmount the USB drive, since it is always marked as "in use" by apache. Here's a removal procedure:

• Close all open files and terminal sessions that are using the drive (the present-working-directory in terminal can cause unmount issues)
• Stop apache: sudo /opt/local/apache2/bin/apachectl stop
• umount /Users/username/ExtraVhosts

Then you can either unmount it graphically or manually (umount /Volumes/Cherrybomb).

If your work and home machines mount the drive to different locations, you could have multiple vhosts folders - home_vhost, work_vhost, etc - and use that in the binding step.

I hope this helps someone out :)

If you point apache to the mountpoint only there shouldn't be an issue. Just don't point Directory directives to directories within the drive.

eg, if you mount /dev/somedisk /mnt/somevhost, the /mnt/somevhost directory will be there whether or not you have the drive mounted and apache will start. Apache doesn't care if the directory is empty so a <Directory "/mnt/somevhost"/> won't cause server to not start if the drive isn't mounted.

Work with UNIX not against it :-p This solution should be sufficient for development.