How Can I Have A Conditional .htaccess Block?

Question

This is an Apache question you've probably come across before. I want to have one source package that I can deploy to my workstation, my staging server, and my production server, but for it to load different .htaccess settings based on what the URL was.

Note that I was using a kludge with an IfModule call, but that won't work with our new production server because it shares all the same modules as my staging server.

Note I need to bundle SetEnv with these rewrites. Currently if you use RewriteCond, it only ties to the following RewriteRule, but not the SetEnv underneath.

Answer 1

Here is a simple example that should be enough for you to change it to meet your requirements:

<IfModule mod_rewrite.c>
    RewriteEngine On

    RewriteBase /

    RewriteCond %{HTTP_HOST} !^localhost
    RewriteCond %{HTTP_HOST} !^www\.
    RewriteRule (.*) http://www.%{HTTP_HOST}/$1 [R=301,L]
</IfModule>

Answer 2

Instead of using SetEnv, use the environment variable setting capabilities of RewriteRule itself:

RewriteCond %{HTTP_HOST} =foo.com
RewriteRule ^ - [E=VARNAME:foo]

RewriteCond %{HTTP_HOST} =bar.com
RewriteRule ^ - [E=VARNAME:bar]

Although I prefer doing this sort of thing by passing flags to the httpd process at startup and looking for them using IfDefine blocks.

<IfDefine FOO>
SetEnv VARNAME foo
</IfDefine>

<IfDefine BAR>
SetEnv VARNAME bar
</IfDefine>

Answer 3

On Ubuntu Linux, the IfDefine's variable is set in

/etc/apache2/envars

and is called APACHE_ARGUMENTS. So, at the bottom of that file I had to add:

export APACHE_ARGUMENTS="-D dev"

...and then bounce the server with:

/etc/init.d/apache2 stop
/etc/init.d/apache2 start

However, there's a Debian article on this topic that discusses this here. In that example, the file to edit is /etc/default/apache2 and the variable is called APACHE_DEFINES.

Likewise, on some systems it is a variable named OPTIONS that is set in /etc/sysconfig/httpd.

So, what you really need to do is look for the start section in your apache2ctl file. So, begin by doing a "whereis apache2ctl" to find where that script is, cat it out and find the start section with the apache2 directive in it, and see if the variable it passes is OPTIONS, APACHE_ARGUMENTS, APACHE_DEFINES, or something else. Then, see which file you need to edit by experimentation with either /etc/sysconfig/httpd, /etc/default/apache2, or /etc/apache2/envvars.