Shared nginx configuration for multiple servers

We have bunch of servers, where we want to share configuration via SVN
or GIT (or whatever). So on all server there will be the same
configuration files set - this is easy to maintain.

Although the most of the configuration is the same on all servers, there
is a small set of differences for certain servers.

I would like to separate this per-server configuration differences into
files called $hostname.conf in the conf.d directory.

However this is not working for me:

 include /etc/nginx/conf.d/$hostname.conf;

Is this supposed to work, or not? If not, what is prefered way to
achieve my goal?

Thanks

Ondrej


Ondrej JOMBIK
Platon Technologies Ltd., Hlavna 3, Sala SK-92701
+421 903 PLATON - [email protected] - http://platon.org

Hello,

I’m no expert but from what I can see in the code (ngx_conf_file.c),
the argument to include directive is not “evaluated”. So, I would say
the behavior you are seeing is “as expected” although probably not the
one you would like…
May be you can confirm by enabling debug on your install. In the logs
you should see a line like "include ".

Good luck.

Antoine.

Yes, I can confirm this, it is not evaluated.

So probably I need to do:

 if ($hostname eq 'servername1') {
     include /etc/nginx/conf.d/servername1.conf;
 }

But I read on MANY places that using if() is evil.

Now I do not know what to do.
Can some expert suggest a prefered way?

Thanks

Ondrej

include isn’t supported inside of “if” either, I believe.

I wanted to do conditional includes before - but ran into a wall.
Someone I believe replied to me off list and said they were trying to
add support for that though.

(I think it might be how the configuration parser works. $hostname is
unknown when the server starts up, and it includes all the includes at
the time of start?) I don’t know.

I see no technical problems with this. Variable $hostname is known when
the server starts, because with $hostname I mean the name of server
where nginx is running (see gethostname(2) call), not the name of
virtual host (which is unknown on the server start, indeed)

If include is not supported inside if(), I’m pretty sure we are lost.
I see no other way how to accomplish this. Maybe Igor, who knows every
byte of code knows:-)

I think this requirement is a desirable feature. I know guys who
maintain hundreds or thousands of nginx servers. Currently they are
copying configuration files back and forth, but if they were able to
make some per-server configuration alternations based on the same
configuration files set, they would be able to put whole nginx
configuration into SVN and do just “svn update” on certain webservers.

Then every webserver will load its specific configuration (in fact main
configuration with some small per-server differences).

Anyway, thank you for your reply.

Ondrej

I’m facing a related issue, although my attempt at implementation is
different from the OP.

ip.conf:
set $server_ip 10.11.1.50;

nginx.conf:

server {
include ip.conf; #adds the $server_ip variable which is
machine-specific
listen $server_ip:80 default_server;

}

This fails with: nginx: [emerg] host not found in “$server_ip:80” of
the “listen” directive in /opt/nginx/conf/nginx.conf:48

What is the best way to include a hard-coded IP address from another
file in order to allow nginx.conf to be universal across deployed
machines?

Cheers,

Dean

Posted at Nginx Forum:

From what I can see, include can go anywhere (which includes the evil
if). The problem is with the directives that are includED. They all
have to be supported inside if, which is unlikely.

Now, regarding your main problem, what about using symbolic links to
provide the desired functionality.

Something like :
include /etc/conf/local.nginx.conf

with /etc/conf/local.nginx.conf being a symbolic link to the file that
is specific for this server.

Antoine.


Join me on my nginx cruise : http://www.nginx-discovery.com

Hello!

On Mon, May 02, 2011 at 03:04:48PM -0400, dbanks wrote:

machine-specific
listen $server_ip:80 default_server;

}

This fails with: nginx: [emerg] host not found in “$server_ip:80” of
the “listen” directive in /opt/nginx/conf/nginx.conf:48

What is the best way to include a hard-coded IP address from another
file in order to allow nginx.conf to be universal across deployed
machines?

Variable are evaluated at runtime during request processing, you
can’t use them to configure listening sockets.

Either place full listen directive in included file or use some
external scripting to produce actual config.

Maxim D.