you could do this via DNS hook of the domain(s). For example:
Change the DNS Settings of domain-b.co.uk
and edit the corresponding DNS entry (CNAME) of the subdomain system
and change the Alias-Name for this subdomain (system.domain-b.co.uk
) to domain-a.com
.
Now all requests to system.domain-b.co.uk
get redirected to your server at domain-a.com
. Then you just have to make sure that the server behind domain-a.com
accepts requests from system.domain-b.co.uk
by adding an vhost OR route all incoming requests of this machine by default to the vhost of myapp.domain-a.com
if no alternative route is defined.
Pros of using a Alias-Name (instead of using a static IP address): if the IP Address of domain-a.com
changes, you don't have to edit the settings of system.domain-b.co.uk
.
PS: DNS Changes may take up to 24-48 hours coming into effect