ingress-nginx: Enabling dynamic configuration doesnt work with external service

Is this a BUG REPORT or FEATURE REQUEST? (choose one): BUG REPORT

NGINX Ingress controller version: 0.16.2

Kubernetes version (use kubectl version):

Client Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.7", GitCommit:"b30876a5539f09684ff9fde266fda10b37738c9c", GitTreeState:"clean", BuildDate:"2018-01-16T21:59:57Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"8+", GitVersion:"v1.8.7+coreos.0", GitCommit:"768e049ab5230010251f30475e0e785e2e999566", GitTreeState:"clean", BuildDate:"2018-01-18T00:17:18Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"

Environment:

Cloud provider or hardware configuration:
OS (e.g. from /etc/os-release):
Kernel (e.g. uname -a):
Install tools:
Others:

What happened: Using an externalname service with my configuration worked until I included the --enable-dynamic-configuration flag. Now nginx isnt redirecting to the external service. Its not resolving the upstream host and keeps returning 502 -bad gateway. See snippet of error below W0717 12:46:10.270803 7 controller.go:773] service foo/fooservice does not have any active endpoints

What you expected to happen: I expect the upstream host to be resolved.

How to reproduce it (as minimally and precisely as possible): Set up an externalName service with no selectors , or endpoints that points to an external service

Anything else we need to know: I believe the issue has to do with the upstream balancer

About this issue

Original URL
State: closed
Created 6 years ago
Comments: 22 (16 by maintainers)

Most upvoted comments

I’ve tracked down “no host allowed” - it’s coming from https://github.com/openresty/lua-nginx-module/blob/master/src/ngx_http_lua_balancer.c

I’ve also found this issue: https://github.com/openresty/lua-resty-core/issues/45

It would appear that currently --enable-dynamic-configuration doesn’t support ExternalName Services as the hostname isn’t resolved in the lua code, or prior to being sent as a backend

mikebryant on Jul 17, 2018

@gjcarneiro we plan to release 0.18.0 at the end of the week

Edit: In the meantime you can use quay.io/aledbf/nginx-ingress-controller:0.406 (contains current master)

aledbf on Aug 6, 2018

Thanks for extensive debugging @mikebryant. I started working on this at https://github.com/kubernetes/ingress-nginx/pull/2804, hopefully will get it shipped before next week. I’m doing it in Nginx/Lua because we already have a mechanism to periodically process endpoints, I’m piggybacking on it to resolve domain names - that means if DNS changes, Nginx will pick up the change in a second (I think currently you have to reload Nginx), so that’s an added benefit.

ElvinEfendi on Jul 18, 2018

Thanks for the very detailed investigation, it’s rare enough to be mentioned 👏

antoineco on Jul 17, 2018