Allow internet users to access privately hosted website pages - apache

Question

I have a corporate private network(VPN) and on one VM a website is hosted which can be accessed internally only. e.g. https://internal.com/welcome.html
Now, I want to allow few pages of the site to be accessible from outside but with their own url.
e.g. they will open http://theirdoamin.com/welcome.html which will be redirected into my private network and internally it will be mapped/proxied to https://internal.com/welcome.html.
This way outside will never know the actual url (i.e https://internal.com/welcome.html.
My question is, can we achieve this using Apache Reverse proxy server sitting in-front of my hosted VM?
Second question, can I also limit the access to welcome.html page only and not others?
My colleague already implemented using Apache Nifi but I still believe it can be simple done using Apache Reverse Proxy setup.
Please advise.
Thanks

Answer 1

1) Yes, Apache reverse-proxy is able to do that.
2) You can limit access as you like.
1) I'd set up two vhosts (for examples), one with the original name and one with the VPN-accessable name.
Listen 80
#If you are running a Apache 2.2 you'll need the following line, for 2.4 you won't
NameVirtualHost *:80
<VirtualHost *:80>
DocumentRoot "srv/www/example1"
ServerName internal.com
<Directory "/srv/www/example1">
Require all granted
</Directory>
# Other directives here, if needed
</VirtualHost>
<VirtualHost *:80>
ServerName external.com
ProxyPreserveHost On
RewriteEngine On
RewriteRule ^ https://internal.com/welcome.html [P]
ProxyPassReverse / https://internal.com/
</VirtualHost>
You'll need the RewriteRule to target a specific file instead of a whole domain. Otherwise a simple ProxyPass would have been enough.
This requires the modules mod_rewrite, mod_proxy and mod_proxy_http to be activated.
2) is done by the RewriteRule. It only allows access to that specific target-file (welcome.html).