# Issue with capturing server name **URL:** \ **Category:** NGINX\ **Created:** [December 12, 2010, 7:27pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461 "2010-12-12T19:27:47Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Dobai-Pataky\_BSSSSl](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/77aa72/32.png) [@Dobai-Pataky\_BSSSSl](https://www.ruby-forum.com/u/Dobai-Pataky_BSSSSl)\ **Post date:** [December 12, 2010, 7:27pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/1 "2010-12-12T19:27:47Z")
Hi, on [http://wiki.nginx.org/HttpCoreModule#server\_name](http://wiki.nginx.org/HttpCoreModule#server_name) i read about capturing the servername with regular expressions. Now i used the following on nginx 0.9.2: server { listen [::]:80 default ipv6only=off; server\_name ~^(?.+).internal.mydomain.tld$; ``` location / { proxy_pass http://1.2.3.4:80; proxy_set_header Host $domain; ``` } } but Host is not set at all on the upstream, because it seems that nginx doesn’t get it captured. The regexp matches, i also tried with ?P as stated on the page with no success. Anything i’m doing wrong here? Thanks and regards, Sven ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 7:59pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/2 "2010-12-12T19:59:12Z")
On Sun, Dec 12, 2010 at 07:26:23PM +0100, Sven ‘Darkman’ Michels wrote: > ``` > location / { > proxy_pass http://1.2.3.4:80; > proxy_set_header Host $domain; > > ``` > > } > } > > but Host is not set at all on the upstream, because it seems that nginx > doesn’t get it captured. The regexp matches, i also tried with ?P > as stated on the page with no success. Anything i’m doing wrong here? If you run nginx with debug log: > **[A debugging log](http://nginx.org/en/docs/debugging_log.html)** you should see something like this: http header: “Host: www.internal.mydonain.tld” … http regex set $domain to “www” – Igor S. > **[Igor Sysoev](http://sysoev.ru/en/)** ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 8:23pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/3 "2010-12-12T20:23:02Z")
Hi, thanks for the quick reply. Am 12.12.2010 19:58, schrieb Igor S.: > If you run nginx with debug log: > [A debugging log](http://nginx.org/en/docs/debugging_log.html) > you should see something like this: > > http header: “Host: www.internal.mydonain.tld” > … > http regex set $domain to “www” ok, debbuging enabled, but nothing with “regex” shows up. I’m getting 2010/12/12 20:10:37 [debug] 32080#0: \*1 http header: “Host: www.internal.mydomain.tld” 2010/12/12 20:10:37 [debug] 32080#0: \*1 http header done which seems to be ok so far, but no regex matching somewhere… Is there a need of some compiling options? nginx itself is liked against pcre lib, so it looks ok so far for me… Regards, Sven ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 8:44pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/4 "2010-12-12T20:44:25Z")
Hi, Am 12.12.2010 20:35, schrieb Igor S.: > > ok, debbuging enabled, but nothing with “regex” shows up. I’m getting > > 2010/12/12 20:10:37 [debug] 32080#0: \*1 http header: “Host: > > www.internal.mydomain.tld” > > 2010/12/12 20:10:37 [debug] 32080#0: \*1 http header done > > > > which seems to be ok so far, but no regex matching somewhere… > > Is there a need of some compiling options? nginx itself is liked against > > pcre lib, so it looks ok so far for me… > > Do you request nginx via ipv4 or ipv6 ? mh, normally v6 but i tried with v4 now, looks the same (its dualstack). Regards, Sven ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 8:36pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/5 "2010-12-12T20:36:13Z")
On Sun, Dec 12, 2010 at 08:22:09PM +0100, Sven ‘Darkman’ Michels wrote: > > … > > http regex set $domain to “www” > > ok, debbuging enabled, but nothing with “regex” shows up. I’m getting > 2010/12/12 20:10:37 [debug] 32080#0: \*1 http header: “Host: > www.internal.mydomain.tld” > 2010/12/12 20:10:37 [debug] 32080#0: \*1 http header done > > which seems to be ok so far, but no regex matching somewhere… > Is there a need of some compiling options? nginx itself is liked against > pcre lib, so it looks ok so far for me… Do you request nginx via ipv4 or ipv6 ? – Igor S. > **[Igor Sysoev](http://sysoev.ru/en/)** ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 8:49pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/6 "2010-12-12T20:49:27Z")
On Sun, Dec 12, 2010 at 08:43:41PM +0100, Sven ‘Darkman’ Michels wrote: > > > pcre lib, so it looks ok so far for me… > > > > Do you request nginx via ipv4 or ipv6 ? > > mh, normally v6 but i tried with v4 now, looks the same (its dualstack). Do you have other servers in configuration ? – Igor S. > **[Igor Sysoev](http://sysoev.ru/en/)** ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 8:55pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/7 "2010-12-12T20:55:05Z")
Hi, Am 12.12.2010 20:48, schrieb Igor S.: > > mh, normally v6 but i tried with v4 now, looks the same (its dualstack). > > Do you have other servers in configuration ? plenty but i got it. You’re right with the v4/v6 thing. It works if i use v4 only (e.g. just a “listen 80;” in the config). So i would say its a bug? Regards, Sven ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 9:06pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/8 "2010-12-12T21:06:26Z")
Hi, Am 12.12.2010 20:59, schrieb Igor S.: > > plenty but i got it. You’re right with the v4/v6 thing. It works if i use v4 > > only (e.g. just a “listen 80;” in the config). So i would say its a bug? > > Do you have “listen” directives with specific addresses ? > How do other “listen” directives look ? nope, its just a very small test config. works: server { listen 80; server\_name ~^(?.+).internal.mydomain.tld$; … } doesn’t: server { listen [::]:80 default ipv6only=off; server\_name ~^(?.+).internal.mydomain.tld$; … } nothing else changed. HTH, Sven ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 9:00pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/9 "2010-12-12T21:00:08Z")
On Sun, Dec 12, 2010 at 08:54:04PM +0100, Sven ‘Darkman’ Michels wrote: > Hi, > > Am 12.12.2010 20:48, schrieb Igor S.: > > > > mh, normally v6 but i tried with v4 now, looks the same (its dualstack). > > > > Do you have other servers in configuration ? > > plenty but i got it. You’re right with the v4/v6 thing. It works if i use v4 > only (e.g. just a “listen 80;” in the config). So i would say its a bug? Do you have “listen” directives with specific addresses ? How do other “listen” directives look ? – Igor S. > **[Igor Sysoev](http://sysoev.ru/en/)** ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 9:47pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/10 "2010-12-12T21:47:10Z")
On Sun, Dec 12, 2010 at 09:05:49PM +0100, Sven ‘Darkman’ Michels wrote: > ``` > server_name ~^(?.+)\.internal\.mydomain\.tld$; > > ``` > > … > } > > nothing else changed. The attached patch should fix the bug. ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 13, 2010, 9:57pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/11 "2010-12-13T21:57:44Z")
Hi! Am 12.12.2010 21:45, schrieb Igor S.: > The attached patch should fix the bug. tested it today, and yes, it seems to fix the problem 🙂 At least all my tests did succeed. Thanks for the quick fix! Regards, Sven ---
**Author:** ![Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e99b99/32.png) [@Sven\_SDarkmanS\_Mich](https://www.ruby-forum.com/u/Sven_SDarkmanS_Mich)\ **Post date:** [December 12, 2010, 9:54pm UTC](https://www.ruby-forum.com/t/issue-with-capturing-server-name/200461/12 "2010-12-12T21:54:41Z")
Hi, Am 12.12.2010 21:45, schrieb Igor S.: > > server { > > listen [::]:80 default ipv6only=off; > > server\_name ~^(?.+).internal.mydomain.tld$; > > … > > } > > > > nothing else changed. > > The attached patch should fix the bug. Ok, will try tomorrow (haven’t time right now, hopefully tomorrow), but thanks a lot for this quick fix. I’ll report back! Regards, Sven