Opened 4 years ago

Closed 4 years ago

Last modified 4 years ago

#1081 closed enhancement (invalid)

ngx_stream_core_module proxy_pass dynamic resolve

Reported by: Watson Yim Owned by:
Priority: major Milestone:
Component: nginx-module Version: 1.11.x
Keywords: proxy_pass, ngx_stream_core_module, stream, tcp Cc:
uname -a: Linux ip-10-0-1-98 4.4.11-23.53.amzn1.x86_64 #1 SMP Wed Jun 1 22:22:50 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
nginx -V: nginx version: nginx/1.11.4
built by gcc 4.8.3 20140911 (Red Hat 4.8.3-9) (GCC)
built with OpenSSL 1.0.1k-fips 8 Jan 2015
TLS SNI support enabled
configure arguments: --user=nginx --group=nginx --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --with-http_ssl_module --with-pcre --with-http_stub_status_module --with-http_realip_module --with-stream

Description

Hi NGINX team,

Awesome work with the TCP reverse proxy! Keep it up!

I have a use case where my proxy_pass destination needs DNS re-resolving every day or so. I did some testing and was unable to setup destination re-resolving. My config is as follows:

/etc/nginx.conf
stream {

resolver 10.0.0.2 valid=10s;
resolver_timeout 10s;
include /etc/nginx/stream.d/*.conf;

}

/etc/nginx/stream.d/tcpbackend.conf is a symlink to /etc/nginx/stream.sites/tcpbackend.conf

/etc/nginx/stream.sites/tcpbackend.conf
server {

listen 1883;

proxy_pass internal-app.example.com:1883;

}

This setup works (as in tcp is successfully routed to the A host at internal-app.example.com, but when there is an A host change, nginx continues to route to the old IP.

This fix is readily available in the http module using "set $be internal-app.example.com" and then "proxy_pass $be". Is there such thing possible for the stream module?

Thanks!

Change History (2)

comment:1 by Maxim Dounin, 4 years ago

Resolution: invalid
Status: newclosed

In stream, there is no set directive, but there are other ways to create variables, including map.

Please use mailing list for further questions. Thank you.

comment:2 by Watson Yim, 4 years ago

Hi mdounin,

Thanks for your help! map did the job. In case anyone is interested, below is the code I used that got it to work:

in /etc/nginx/stream.sites/tcpbackend.conf:
map internal-app.example.com $be {

default "internal-app.example.com";

}

server {

listen 1883;

proxy_pass $be:1883;

}

Thanks again!

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