I got a K8s cluster based on CentOS8 with the following nodes:
node1: 129.X.X.193 (master1)
node2: 129.X.X.195 (master2)
node3: 129.X.X.194 (worker)
I installed Kubernetes using Kubespray (v2.15.1) with mainly the default settings and it installed everything fine - here are the pods:
$ kubectl get pods -n kube-system
calico-kube-controllers-75f8564897-f9j48 1/1 Running 0 141m
calico-node-cx4js 1/1 Running 0 141m
calico-node-gtcxm 1/1 Running 0 141m
calico-node-pw9kt 1/1 Running 0 141m
coredns-7677f9bb54-qx5w8 1/1 Running 0 140m
coredns-7677f9bb54-ttjkm 1/1 Running 0 140m
dns-autoscaler-6b849f6697-85v55 1/1 Running 0 140m
kube-apiserver-node1 1/1 Running 0 144m
kube-apiserver-node2 1/1 Running 0 143m
kube-controller-manager-node1 1/1 Running 0 144m
kube-controller-manager-node2 1/1 Running 0 143m
kube-proxy-7mjdk 1/1 Running 0 142m
kube-proxy-dr2x2 1/1 Running 0 142m
kube-proxy-qrpx9 1/1 Running 0 142m
kube-scheduler-node1 1/1 Running 0 144m
kube-scheduler-node2 1/1 Running 0 143m
nginx-proxy-node3 1/1 Running 0 142m
nodelocaldns-hxjmt 1/1 Running 0 140m
nodelocaldns-jctwx 1/1 Running 0 140m
nodelocaldns-khdsl 1/1 Running 0 140m
Now I want to check the network plugin using a sample nginx deployment:
$ kubectl create deployment nginx --image=nginx
deployment.apps/nginx created
$ kubectl expose deployment/nginx --type="NodePort" --port=8080 --target-port=80 --overrides '{ "spec":{"ports":[{"port":8080,"targetPort":80,"protocol":"TCP","nodePort":31704}]}}'
service/nginx exposed
Pod as well as service looks fine:
$ kubectl get svc -n kube-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
coredns ClusterIP 10.X.X.3 <none> 53/UDP,53/TCP,9153/TCP 142m
nginx NodePort 10.X.X.22 <none> 8080:31704/TCP 29m
From my understanding I should now be able to access that service from all 3 nodes, however only 2 of 3 nodes are working:
Node1 & Node3 (hostnames as well as IPs) are showing everything as expected:
$ curl node1:31704
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
However when I use node2 it is stuck:
$ curl -v node2:31704
* Rebuilt URL to: node2:31704/
* Trying 129.X.X.195...
* TCP_NODELAY set
Using the internal ClusterIP also works fine (curl 10.X.X.22:8080)
Any idea what I'm doing wrong or any further information needed? Thanks!
