Microk8s: exposing service not working outside a vm

[carmine]

Using multipass to launch a vm.
With the vm launched launched, and access to it's shell, I do the following (roughly):

sudo snap install microk8s --classic --beta
microk8s.enable dns dashboard
alias kubectl=microk8s.kubectl
kubectl run echoserver --image=gcr.io/google_containers/echoserver:1.4 --port=8080 --replicas=2
kubectl expose deployment echoserver --type=NodePort
kubectl describe services/echoserver     # get its assigned nodeport
lynx http://localhost:<nodeport>   ## this works

from outside the vm

• chrome: http://<vm_ip_addr>:<nodeport>
• this fails

But, back in the VM

sudo iptables -P FORWARD ACCEPT

Now I can access from outside VM - chrome: http://<vm_ip_addr>:<nodeport>

There's a related bug in github - https://github.com/kubernetes/kubernetes/issues/58908 - but this was closed, at it seemed that there was a networking configuration issue, or something like that.

[amir3code]

Its not a bug!
You missed something!
You should specify the Pod Port, the Target Port, the External IP and you should set type to ClusterIP.

kubectl expose deployment echoserver --port 8080 --target-port 80 --external-ip 192.168.214.130 --type ClusterIP

external-ip is the IP of the whole VM that MicroK8S is running on. target-port is the port of the Deployment / Pods that you want to expose and port is the port of external ip you want to expose.

[aiankoulski]

Experienced the same issue in microk8s stable/1.14 on Ubuntu 18 and Amazon Linux 2.
With microk8s stable/1.15, verified that services exposed on NodePort or ClusterIP with --external-ip work as expected and are accessible from external sources.

[gdubicki]

The "Experience MicroK8s" is misleading at least for macOS users, as it tells you to run:

ubuntu@juju-c42409-default-0:~$ sudo microk8s kubectl expose deployment nginx --port 80 --target-port 80 --selector app=nginx --type ClusterIP --name nginx    

...while in fact you should also check the vm IP with:

gdubicki@mac ~ $ multipass list
Name                    State             IPv4             Image
microk8s-vm             Running           192.168.64.2     Ubuntu 18.04 LTS

...and add --external-ip 192.168.64.2 to the command.
Then of course you should curl 192.168.64.2.