Redirect rule to allow sub.domain.com to only serve images - redirect

Question

I need help with a redirect rule.
I created a subdomain sub.abc.com and set it's public_html to that of abc.com.
This means public_html is now accessible either by abc.com or by sub.abc.com .
I want to limit this so that sub.abc.com only provides access to images in wp-content/uploads any other requests to sub.abc.com should be redirected to abc.com/url/url .
Here is what i have tried creating
RewriteCond %{HTTP_HOST} ^cdn.example.com
RewriteCond %{REQUEST_URI} !^/wp-content/uploads/$1
RewriteRule ^(.*)$ http://example.com/$1 [L,R=301]
so if the user is accessing cdn.example.com/wp-content/uploads/1/1/file.jpg then there is no redirect, but if they are trying to access cdn.example.com/post/post or cdn.example.com/anything-else then it will redirect to example.com/post/post or example.com/anything-else .

Answer 1

The following rule should work for you. Remember to put it at the of your htaccess or server.config file before others rules otherwise these rules may override it.
RewriteEngine on
#serve only images on abc.example.com
#redirect to main domain if request is not for images
######################
#if the host is "sub.example.com"
RewriteCond %{HTTP_HOST} ^sub\.example\.com$ [NC]
#and the request is not for images and /wp-content/uploads
RewriteCond %{REQUEST_URI} !/wp-content/uploads/?$ [NC]
RewriteCond %{REQUEST_URI} !\.(jpg|png|gif|jpeg)$ [NC]
#redirect the request to main domain
RewriteRule ^ https://example.com%{REQUEST_URI} [L,R=302]
This will redirect your sub.example.com with request string to example.com if the subdomain is used for requests other then images .
Replace sub.example.com and example.com with your real domain name in the RewriteCond and RewriteRule above.
If this works and you are happy with the redirect then change R=302 to R=301 to make the redirection permanent.