# HTTP status codes missing description in header for proxy\_pass

**URL:** <https://www.ruby-forum.com/t/http-status-codes-missing-description-in-header-for-proxy-pass/245486>\
**Category:** NGINX\
**Created:** [June 4, 2013, 1:08am UTC](https://www.ruby-forum.com/t/http-status-codes-missing-description-in-header-for-proxy-pass/245486 "2013-06-04T01:08:11Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**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:** [June 4, 2013, 1:08am UTC](https://www.ruby-forum.com/t/http-status-codes-missing-description-in-header-for-proxy-pass/245486/1 "2013-06-04T01:08:11Z")

</div>

We’re using nginx as a middle layer in front of our application server  
(mod\_perl). When mod\_perl returns an error page, the HTTP status line  
is  
missing the “reason phrase” after the status code, like “Not Found”,  
e.g.

HTTP/1.1 404  
Server: nginx/1.2.1  
…etc

should be

HTTP/1.1 404 Not Found  
…etc…

AFAICT, the HTTP spec requires at least a space after the status code:

* * *

[http://www.w3.org/Protocols/rfc1945/rfc1945](http://www.w3.org/Protocols/rfc1945/rfc1945)  
The first line of a Full-Response message is the Status-Line,  
consisting of the protocol version followed by a numeric status code  
and its associated textual phrase, with each element separated by SP  
characters. No CR or LF is allowed except in the final CRLF sequence.

```
   Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF

```

Since a status line always begins with the protocol version and  
status code

```
   "HTTP/" 1*DIGIT "." 1*DIGIT SP 3DIGIT SP

```

## (e.g., "HTTP/1.0 200 "),

```
   Reason-Phrase = *<TEXT, excluding CR, LF>

```

* * *

The reason we noticed is that putting Perlbal in front of nginx got the  
status rejected, since Perlbal is written to strictly follow the spec:

* * *

return fail(“Bogus response line”) unless  
$self-\>{responseLine} =~  
m!^HTTP/(\d+).(\d+)\s+(\d+)(?:\s+(.\*))$!;

---

<div class="post-metadata">

**Author:** ![kgoess](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/258eb7/32.png) [@kgoess](https://www.ruby-forum.com/u/kgoess)\
**Post date:** [June 4, 2013, 1:20am UTC](https://www.ruby-forum.com/t/http-status-codes-missing-description-in-header-for-proxy-pass/245486/2 "2013-06-04T01:20:28Z")

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Hi,

nginx does its job correctly:

$ curl -I [http://nginx.org/404](http://nginx.org/404)  
$ HTTP/1.1 404 Not Found  
$ […]

I guess the irregular response comes from your mod\_perl backend? Did you  
check that out?

Capturing nginx’s debug output of such a request will probably help.

[http://nginx.org/en/docs/debugging\_log.html](http://nginx.org/en/docs/debugging_log.html)

Regards,  
Lukas

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<div class="post-metadata">

**Author:** ![kgoess](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/258eb7/32.png) [@kgoess](https://www.ruby-forum.com/u/kgoess)\
**Post date:** [June 4, 2013, 12:56pm UTC](https://www.ruby-forum.com/t/http-status-codes-missing-description-in-header-for-proxy-pass/245486/3 "2013-06-04T12:56:28Z")

</div>

Hello!

On Mon, Jun 03, 2013 at 07:07:50PM -0400, kgoess wrote:

> HTTP/1.1 404 Not Found  
> …etc…

[…]

> Is this a bug in nginx, or a configuration issue that we can fix? The patch  
> to Perlbal is simple enough, is it worth looking for a patch to nginx? Or  
> did we miss something else entirely?

As soon as you proxy requests to another server - nginx just  
returns a status line as got from a backend as soon as it’s able  
to recognize it.

–  
Maxim D.

> **[nginx: donation](http://nginx.org/en/donation.html)**

---

<div class="post-metadata">

**Author:** ![kgoess](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/258eb7/32.png) [@kgoess](https://www.ruby-forum.com/u/kgoess)\
**Post date:** [June 4, 2013, 10:09pm UTC](https://www.ruby-forum.com/t/http-status-codes-missing-description-in-header-for-proxy-pass/245486/4 "2013-06-04T22:09:54Z")

</div>

> I guess the irregular response comes from your mod\_perl backend?

Aha, from ngrep listening on port 8080 responding to nginx, it is indeed  
missing the description:

T 10.200.1.59:8080 → 10.200.1.59:57990 [AP]  
HTTP/1.1 404..Server: Apache/2.2.16 (Debian) mod\_perl/2.0.4  
Perl/v5.10.1

If apache is in the middle layer, instead of nginx, it looks like apache  
fills in the status line

T 127.0.0.1:8082 → 127.0.0.1:37887 [AP]  
HTTP/1.1 404 Not Found..Date: Tue, 04 Jun 2013 20:02:03 GMT..Server:  
Apache/2.2.16 (Debian) mod\_perl/2.0.4 Perl/v5.10.1..

but if nginx is in the middle, it just passes it straight through:

T 127.0.0.1:8083 → 127.0.0.1:46829 [AP]  
HTTP/1.1 404..Server: nginx/1.2.1..

And sure enough, some pretty old cgi code needed this fix

```
 if (! -e $file) {
   bepress::Statsd->increment('viewcontent.error.native_not_found');

```

- 

```
 $self->out( $cgiutils->header( -status => 404 ) );

```

- 

```
 $self->out( $cgiutils->header( -status => '404 Not Found' ) );
 $self->out( $cgiutils->start_html(

```

Thanks for the help!

Posted at Nginx Forum:  
[http://forum.nginx.org/read.php?2,239811,239869#msg-239869](http://forum.nginx.org/read.php?2,239811,239869#msg-239869)