This article is in quick note form and needs to be flushed out into an article.
In some cases you want to force what a consistent url for a variety of reasons,
- Vendor or product code that works with only a specific url
- Improve index results from search engines
- Enforcing a www. points to a CNAME record and puts you in a better position for DDoS DNS mitigation with a CDN
This can be accomplished using Apache's Rewrite.
This website uses this feature where http://bonsaiframework.com will redirect to http://www.bonsaiframework.com
Enable Rewrite Module
With Ubuntu this is very easy,
sudo a2enmod
Will result in showing a list of modules that you can enable. You want to enable rewrite. If it is not there than it might already be enabled.
Verify Rewrite Module
It is actually somewhat difficult to verify that the module is loaded.
Fill in ways here.
Apply Directives
# Enforce www in front of url.
RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.bonsaiframework\.com$ [NC]
RewriteRule (.*) http://www.bonsaiframework.com$1 [R,L]
I usually place these rules right after my ServerAlias lines in my virtual host.
Debugging
Talk about how to enable logging here.