Domain – Simulate different domains on the same machine

domaindomain-name-system

I'm going to have 2 servers (SSO and application server) running on the same machine but listening on different ports. Is it possible to assign them following addresses: example.com and app.example.com so that the second would be a subdomain of the first?

How would I achieve this? would I use a hosts file or Active Directory?

Edit:
I'm not going to use IIS. I want to test OpenAM product which will be deployed as Tomcat application (most likely listening on 8080 port), and I want to install OpenAM policy agent on Glassfish application server which will host some web application probably listening on 9090 port.
Now what I want to achieve is to redirect all example.com requests to 10.11.11.22:8080 and app.example.com to 10.11.11.22:9090.

Best Answer

You can have more than one website running on the same web server, using host headers / virtual hosts. This is a mechanism where the web server looks at the hostname the browser supplied (used to reach the web server) and serves content from the appropriate website.

You don't even need to define different ports for http websites if you define them each with unique host headers. If you'd rather have different ports then this is also pretty easy in most web servers (you don't say what web server you're using).

As for how to set up the names of the sites, this is also fairly easy, though its not really anything to do with active directory, and I wouldn't personally use hosts files for anything other than dev testing on a local webserver. You would simply create entries in DNS for the two website addresses, pointing to the web server.

So you'd create an "A" record for the hostname & IP address of the web server itself (e.g. mywebserver.example.com) and then use two "CNAME" records (aliases) that point example.com and app.example.com at that A record. This tells any client that looks up either of those two website addresses in DNS to use the IP address defined for the webserver itself.

update to address edit

There's no way to have port number included in in a host name or IP address. Your users will have to type in example.com:8080 and app.example.com:9090. What you're asking for is outside the scope of what can be done in DNS or hosts files because its not related to name resolution.

The two ways to get around that that I can think of would be

To create two seperate virtual servers, each with the application installed on a webserver listening on port 80.
Install IIS (or whatever) on port 80 and have a site for each host header there, as I describe above. Then use redirection from each site to the "correct" one listening at whatever port.

Related Solutions

Domain – Multiple Domains Single Tomcat 7 – Apache Mod_proxy

This sounds rather complicated to me and not the way I would try to run it.

In general I try to separate as much as I can environments from each other, running on different servers ideally , but i understand this is not something you can do with a single VPS.

You should at least separate tomcat instances, this would reduce the mess and makes everything more clear.

I would

1) Start 2 different tomcat instances ( achievable in different ways depending on which distribution you are running) on different ports , prod:8080 and test:8180

2) Enable NameVirtualHost in your Apache configuration and proxy the right servername to the right tomcat instance

# Ensure that Apache listens on port 80
Listen 80

# Listen for virtual host requests on all IP addresses
NameVirtualHost *:80

<VirtualHost *:80>
DocumentRoot /www/example1
ServerName www.mytestdomain.com

# Other directives here

ProxyPreserveHost On

ProxyPass / http://localhost:8080/
ProxyPassReverse / http://localhost:8080/

</VirtualHost>

<VirtualHost *:80>
DocumentRoot /www/example2
ServerName test.mytestdomain.com

# Other directives here
ProxyPreserveHost On

ProxyPass / http://localhost:8180/
ProxyPassReverse / http://localhost:8180/
</VirtualHost>

this way your environment are completely separate and you can apply changes to test without affecting prod , not just inside your code but also at the tomcat configuration level and apache configuration level.

Nginx Proxy – Dynamic proxy_pass DNS Resolution Issues

When you are using variables in a proxy_pass directive, nginx will use runtime resolving except if :

the target server is declared as an IP address
the target server name is part of an upstream server group
the target server name has already been resolved (e.g. it matches a server name in another server block)

Here, a runtime resolver won't help as localhost may not be resolved by a DNS. Also it's a waste to have runtime resolving as you can clearly avoid it here.

So, two simple solutions :

use 127.0.0.1
declare an upstream block if you have server names or a pool of target servers

Now you need your proxied server redirection to be correct. So either :

your proxy target handles the host header and you pass it through with :

proxy_set_header "Host" $host;
your proxy target can't handle the Host header for redirects and you need to rewrite them with nginx using :

proxy_redirect http://$proxy_host/$sub_domain http://$host;

However if it doesn't support the Host header at all, links will be broken.

Best Answer

Related Solutions

Domain – Multiple Domains Single Tomcat 7 – Apache Mod_proxy

Nginx Proxy – Dynamic proxy_pass DNS Resolution Issues

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