# Dynamic server name and aliases

**URL:** <https://www.ruby-forum.com/t/dynamic-server-name-and-aliases/244097>\
**Category:** NGINX\
**Created:** [February 19, 2016, 8:23am UTC](https://www.ruby-forum.com/t/dynamic-server-name-and-aliases/244097 "2016-02-19T08:23:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Rafa\_F](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\
**Post date:** [February 19, 2016, 8:23am UTC](https://www.ruby-forum.com/t/dynamic-server-name-and-aliases/244097/1 "2016-02-19T08:23:23Z")

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Hi everybody,  
I manage server, where each user has own subdomain:  
i1.domain → user #1  
i2.domain → user #2  
etc

I have a nginx config to handle user’s subdomains:

server {  
listen \*:80;  
server\_name ~^i(?\d+).domain$;  
…  
}

It works fine. I have single config to handle all requests for all  
subdomains.

I need to allow users specify custom domains as aliases, e.g.:

i1.domain, [super-user.com](http://super-user.com), [another-domain.net](http://another-domain.net) → user #1  
i2.domain, custom.domain → user #2

How can I add aliases without copy/paste config for each user?

Posted at Nginx Forum:

> **[dynamic server name and aliases](https://forum.nginx.org/read.php?2,264612,264612#msg-264612)**
>
> Hi everybody, I manage server, where each user has own subdomain: i1.domain -\> user #1 i2.domain -\> user #2 etc I have a nginx config to handle user's subdomains: server { listen \*:80; server\_name ~^i(?\<instanceId\>

---

<div class="post-metadata">

**Author:** ![spyfox](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ac91a4/32.png) [@spyfox](https://www.ruby-forum.com/u/spyfox)\
**Post date:** [February 20, 2016, 9:59am UTC](https://www.ruby-forum.com/t/dynamic-server-name-and-aliases/244097/2 "2016-02-20T09:59:08Z")

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On Fri, Feb 19, 2016 at 02:22:35AM -0500, spyfox wrote:

Hi there,

> server {  
> listen \*:80;  
> server\_name ~^i(?\d+).domain$;  
> …

Presumably later in this config, you do something with $instanceId,  
and you have a way to handle it not being set.

> It works fine. I have single config to handle all requests for all  
> subdomains.
> 
> I need to allow users specify custom domains as aliases, e.g.:
> 
> i1.domain, [super-user.com](http://super-user.com), [another-domain.net](http://another-domain.net) → user #1  
> i2.domain, custom.domain → user #2
> 
> How can I add aliases without copy/paste config for each user?

Use “map” to turn your list of domains into the appropriate  
instanceId. Then change your server\_name directive not to set that  
variable.

Something like:

map $host $instanceId {  
hostnames;  
default “”;  
~^i(?P\d+).domain$ $a;  
 [super-user.com](http://super-user.com) 1;  
[another-domain.net](http://another-domain.net) 1;  
custom.domain 2;  
}

server {  
listen \*:80 default;  
server\_name whatever;  
…  
# use $instanceId if it is set  
}

You could also set the default $instanceId to a particular value that  
means “not set”, and have the rest of the system use that value for an  
“unknown” account.

The alternative approach would be to have a separate server{} block  
for each account, with lots of duplication that is handled by your  
config-generator-from-template system. But f you want a single server{}  
block, the above is probably the simplest way.

Good luck with it,

## f

Francis D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)