Apache2 mixing mod_vhosts_alias and mod_rewrite

Question

The Apache2 docs recommend mod_rewrite as a last resort for specifying which directory to send a given host request to. They said use mod_vhosts_alias. I set that up and its working without problem. However, I have a specific case that entails some mod_rewriting.

I have a domain like mydomain.com and a large number of subnames like sub.mydomain.com and sub2.mydomain.com. These subdomains all map to corresponding directories. But the subdomains will also have full top-level domains that map to respective directories. For instance:

sub.mydomain.com will map to the same directory as awesomeproducts.com sub2.mydomain.com will map to the same directory as widgets.com

What would be the best way to make sure both these methods of accessing each site will work without conflict?

Since the docs only say mod_rewrite isn't as "graceful" as mod_vhosts_alias, I didn't know if I ought to use mod_rewrite completely by itself for my situation or if I should be trying to mix the two approaches somehow.

Is mixing them the way to go or will that create problems?

Answer 1

The behaviors of RewriteRule and RewriteCond change when using mod_vhost_alias. Its been a few days since I tinkered with it so I'm sketchy on it, but watch out for the way RewriteRule interprets the portion of the URL to be rewritten. It may change when using mod_vhost_alias... and RewriteCond behavior might change too.

To accomplish the question I was asking about, I ended up using symbolic links for the actual domains. I setup a bunch of subdomains with associated folders so that sub1.stddomain.com would go to the folder sub1.stdomain.com. Then I added a symbolic link that maps domain1.com to the sub1.stddomain.com folder. That way anyone who visits domain1.com is shown the site in the sub1.stddomain.com folder.

IMPORTANT: After all that work and testing, I ended up going back to to a collection of virtualhost files WITHOUT mod_vhost_alias. Turns out that there is a known problem with mod_vhost_alias. DocumentRoot isn't correctly set when using it. This breaks tons of scripts. It was patched in February 2012 with new special variables and the programming team at Apache dropped the ball. They never wrote any documentation explaining how to use the patch or new variables.

I reopened the issue and stated that its still a bug since you can't write code and not tell anyone how to use it and then call it fixed. Unfortunately the issue had already been ignored for YEARS and it will probably continue to get ignored even though they supposedly wrote code for it.

RECOMMENDED LESSON FROM ALL THIS: Don't use mod_vhost_alias. Write shell scripts to manage your vhost files using one more template files.