Setting custom response headers

ehudros2 · June 3, 2009, 11:42am

Hi all,
I’m trying something that I though should be quite simple but turns out
it isn’t…
I have a rails app and want all static assets with a timestamp query
string to be sent with a custom response header called “User-Expires”,
instead of the regular “expires” directive.
I’m coming from apache, and I’m not sure if proxy_set_header is what I’m
looking for or not.
In any case, I’m using the following code:

if ($request_uri ~* “.(ico|css|js|gif|jpe?g|png|swf)?[0-9]+$”) {
expires 30d;
proxy_set_header User-Expires 300d;
break;
}

And I’m getting the following error:
28514#0: “proxy_set_header” directive is not allowed here

I tried moving it to the top (right under all my other proxy_set_headers
and it didn’t return an error but also did not seem to set the header.

I’m totally confused here - why is it called proxy_set_header when I’m
not even using a proxy - i’m just returning the static asset without
proxying anything to mongrel. Am I totally missing something here?
Thanks

Posted at Nginx Forum:

ehudros2 · June 3, 2009, 1:51pm

On Wed, Jun 03, 2009 at 05:36:50AM -0400, ehudros2 wrote:

                   break;
            }
And I’m getting the following error:
28514#0: “proxy_set_header” directive is not allowed here

I tried moving it to the top (right under all my other proxy_set_headers and it didn’t return an error but also did not seem to set the header.

I’m totally confused here - why is it called proxy_set_header when I’m not even using a proxy - i’m just returning the static asset without proxying anything to mongrel. Am I totally missing something here?

I do not know why do use proxy_set_header if you are not even using a
proxy.

Probably, you need

location ~* \.(ico|css|js|gif|jpe?g|png|swf)$ {
    if ($args ~ ^\d+$) {
        add_header  User-Expires 300d;
    }
}

ehudros2 · June 4, 2009, 7:22am

OMG, add_header…
That’s what’s i’ve been looking for the entire morning. I’ve tried so
many different searches on how to add custom headers - they’ve all lead
me to the proxy_pass_header.

Thanks

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ehudros2 · June 4, 2009, 8:09am

On Wed, Jun 03, 2009 at 08:24:14AM -0400, ehudros2 wrote:

How can I set that header to 30 days from now, as I do with expires 30d?
Thanks a lot!

No way. “expires” handles parameter specially.

ehudros2 · June 4, 2009, 7:34am

How can I set that header to 30 days from now, as I do with expires 30d?
Thanks a lot!

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ehudros2 · June 4, 2009, 8:39am

So there is no way I can calculate a time string in runtime unless I’m
using expire?

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ehudros2 · June 4, 2009, 9:03am

On Wed, Jun 03, 2009 at 09:28:06AM -0400, ehudros2 wrote:

So there is no way I can calculate a time string in runtime unless I’m using expire?

You may try to use builtin perl:

http {
perl_var $user_exp
‘sub { return scalar (localtime(time() + 300 * 86400)) }’;

location …

    add_header  User-Expires  $user_exp;

ehudros2 · June 5, 2009, 4:18am

Looks awesome, but seems like I dont have the perl module installed?
I get a "unknown directive “perl_var” error…
I’ve tried searching for the perl module but it seems like the docs are
in russian. Is there a way I can compile it into ngnix?

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ehudros2 · June 8, 2009, 5:34am

ehudros2 wrote:

anyone? I’m getting lost with this perl module stuff here
is it already in the nginx apt packed I installed? if it is, why is perl_var unidentified?

Posted at Nginx Forum: Re: Setting custom response headers

You need to build your own nginx - see

http://wiki.nginx.org/NginxEmbeddedPerlModule

ehudros2 · June 8, 2009, 5:36am

I think 0.8.x should introduce pluggable modules.

Then the distros could support a stripped down basic version with
optional modules, and then just have a “module foo;” line or something
in the nginx.conf. I don’t think it would take too much overhead as
it’s only run during startup…

ehudros2 · June 8, 2009, 6:25am

On Sun, Jun 07, 2009 at 03:26:58AM -0700, Michael S. wrote:

I think 0.8.x should introduce pluggable modules.

Then the distros could support a stripped down basic version with
optional modules, and then just have a “module foo;” line or something
in the nginx.conf. I don’t think it would take too much overhead as
it’s only run during startup…

I thought about dynamic loadable modules (and it’s really very
intresting
to me from technical point of view ), however, if I will ever
implement
this, the loading will be allowed only on start, but not on
reconfiguration,
since unloading with removing dependences is complex thing.
Anyway it’s not 0.8.x thing.

ehudros2 · June 8, 2009, 2:25am

anyone? I’m getting lost with this perl module stuff here
is it already in the nginx apt packed I installed? if it is, why is
perl_var unidentified?

Posted at Nginx Forum:

ehudros2 · June 8, 2009, 6:38am

Definately. It would be a lot better than having to compile nginx
custom for each module you want. Just a simple .so file or something
that takes effect on a start or restart only still works better.
Somehow doing it via graceful reload would be even better

This way modules can be written and deployed any time.

ehudros2 · June 8, 2009, 2:34pm

On Sun, Jun 07, 2009 at 07:58:49AM -0400, ehudros2 wrote:

Thanks for the help guys…
Here’s my configure line:
./configure --sbin-path=/usr/sbin --with-http_ssl_module --conf-path=/etc/nginx --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --with-http_perl_module --prefix=/etc/nginx

I get a ton of “undefined reference” errors when it tries to compile the perl module (like “undefined reference to perl_free' objs/src/http/modules/perl/ngx_http_perl_module.o: In functionngx_http_perl_xs_init’”)
although I do have perl 5.8.8 installed. Do I need perl build headers? How do i install them?
This is a much more difficult task than I originally thought it’d be

What does ./configure show near this line:

checking for perl

and what does

grep lperl objs/Makefile

show ?

ehudros2 · June 8, 2009, 7:14am

Thanks for the help guys…
Here’s my configure line:
./configure --sbin-path=/usr/sbin --with-http_ssl_module
–conf-path=/etc/nginx --error-log-path=/var/log/nginx/error.log
–http-log-path=/var/log/nginx/access.log --with-http_perl_module
–prefix=/etc/nginx

I get a ton of “undefined reference” errors when it tries to compile the
perl module (like “undefined reference to perl_free' objs/src/http/modules/perl/ngx_http_perl_module.o: In function ngx_http_perl_xs_init’”)
although I do have perl 5.8.8 installed. Do I need perl build headers?
How do i install them?
This is a much more difficult task than I originally thought it’d be

Posted at Nginx Forum:

ehudros2 · June 9, 2009, 2:20am

Hi guys,
seems like ./configure does not check for perl (I dont see that line and
./configure | grep perl also comes back empty).
So does “grep lperl objs/Makefile”.

Any idea why that is?
I’m really thankful for all your help

Posted at Nginx Forum:

ehudros2 · June 10, 2009, 9:51am

(bump)

Posted at Nginx Forum:

ehudros2 · June 11, 2009, 11:27am

Guys, I really feel bad about bumping a second time in 2 days, but I’m
being hammered here for not getting this done
Can someone please throw in his thoughts on why I can’t get the perl
module installed?

Thanks!

Posted at Nginx Forum:

ehudros2 · June 11, 2009, 2:35pm

Hallelujah! I finally got it to work with you great help.
Thanks

BTW - it was not perl_var but perl_set that did the trick, if anyone
needs something like this in the future.

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ehudros2 · June 11, 2009, 11:33am

On Mon, Jun 08, 2009 at 03:04:47AM -0400, ehudros2 wrote:

Hi guys,
seems like ./configure does not check for perl (I dont see that line and ./configure | grep perl also comes back empty).
So does “grep lperl objs/Makefile”.

Any idea why that is?
I’m really thankful for all your help

Could you show full configure output, including command line ?