How to get hostname into rewriterule

Question

We've got a few subdomains setup, and I want to simplify some apache configuration - particularly as these particular subdomains are volatile. Anyway, I'm trying to get a rewrite rule that include the host.

So far, I've got:

RewriteEngine On

RewriteCond %{HTTP_HOST} ^(.*).net.au$
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%1.net.au$1 [R=302,L]

This is based on https://stackoverflow.com/questions/3634101/url-rewriting-for-different-protocols-in-htaccess and http://httpd.apache.org/docs/2.4/rewrite/vhosts.html

However, the pattern in the first condition isn't written into the rewritten address, and I end up being sent to .net.au/wherever (wouldn't let me post with the https in front) - have I missed something?

Running apache 2.4 on Ubuntu 14.04

Solution

The simple case suggested by Ladadadada works when the domain name is same between requested host and intended host:

RewriteEngine On

RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}$1 [R=302,L]

However, an extra difficulty is that I also need to have http:// sub-domain.local redirect to http:// sub-domain.net.au - so using %{HTTP_HOST} wouldn't be sufficient.

I had another look at some examples, and realised that the %1 back-reference seems to only apply to the RewriteCond immediately prior to RewriteRule.

I reordered things:

RewriteEngine On

RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} ^(.*)(.local|.net.au)$
RewriteRule ^(.*)$ https://%1.net.au$1 [R=302,L]

And the redirects work great

Comments

[Ladadadada]

That looks needlessly complicated. Why not just Redirect to https://%{HTTP_HOST}$1 and get rid of the first RewriteCond?

[HorusKol]

@Ladadadada because I didn't know you could do that - but after re-reading the manual the Substitution string can include server-variables as in rule condition test-strings (%{VARNAME})

[HorusKol]

@JennyD could you link to where my question is answered there?