I have a kubernetes setup running nicely, but I can't seem to expose services externally. I'm thinking my networking is not set up correctly:
kubernetes services addresses: --service-cluster-ip-range=172.16.0.1/16
flannel network config: etcdctl get /test.lan/network/config {"Network":"172.17.0.0/16"}
docker subnet setting: --bip=10.0.0.1/24
Hostnode IP: 192.168.4.57
I've got the nginx service running and I've tried to expose it like so:
[root@kubemaster ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-px6uy 1/1 Running 0 4m
[root@kubemaster ~]# kubectl get services
NAME LABELS SELECTOR IP(S) PORT(S) AGE
kubernetes component=apiserver,provider=kubernetes <none> 172.16.0.1 443/TCP 31m
nginx run=nginx run=nginx 172.16.84.166 9000/TCP 3m
and then I exposed the service like this:
kubectl expose rc nginx --port=9000 --target-port=9000 --type=NodePort
NAME LABELS SELECTOR IP(S) PORT(S) AGE
nginx run=nginx run=nginx 9000/TCP 292y
I'm expecting now to be able to get to the nginx container on the hostnodes IP (192.168.4.57) - have I misunderstood the networking? If I have, can explanation would be appreciated :(
Note: This is on physical hardware with no cloud provider provided load balancer, so NodePort is the only option I have, I think?
So the issue here was that there's a missing piece of the puzzle when you use nodePort.
I was also making a mistake with the commands.
Firstly, you need to make sure you expose the right ports, in this case 80 for nginx:
kubectl expose rc nginx --port=80 --type=NodePort
Secondly, you need to use kubectl describe svc nginx and it'll show you the NodePort it's assigned on each node:
[root@kubemaster ~]# kubectl describe svc nginx
Name: nginx
Namespace: default
Labels: run=nginx
Selector: run=nginx
Type: NodePort
IP: 172.16.92.8
Port: <unnamed> 80/TCP
NodePort: <unnamed> 32033/TCP
Endpoints: 10.0.0.126:80,10.0.0.127:80,10.0.0.128:80
Session Affinity: None
No events.
You can of course assign one when you deploy, but I was missing this info when using randomly assigned ports.