One worker node has already installed a nginx and listened on port 80. I want to leverage ingress-nginx and keep former service in worker node still working. Is there any way to merge ingress-nginx with existing nginx on worker node?
I'm working on baremetal environment.
The ingress-nginx has its own nginx running, it watches the resources at the api-server and update the nginx configuration dynamically, while the nginx uses the static configuration, so they can't be merged together. I guess you can configure ingress to access nginx through ingress-nginx.
Having multiple pods listening on port 80 should not be an issue as they should be in their own network namespaces, unless you explicitly run them with hostNetwork: true which in most cases you should not.
For running nginx-ingress on baremetal you should expose it with NodePort Service on predefined ports like ie. 32080 and 32443, which will make your ingress availabe on all the nodes on these ports, and then configure your network so that some IP 80/443 traffic is directed by your loadbalancer to kube nodes on these predefined ports