generate the polycubectl binary for pcn_k8s docker image

[goldenrye]

By default there is no polycubectl binary included in our official published pcn-k8s docker image: https://hub.docker.com/r/polycubenetwork/k8s-pod-network. We need this binary to help user to get more information of cubes running in the docker.

[acloudiator]

@goldenrye Could you please add some description to this PR?! Thanks!

[goldenrye]

@goldenrye Could you please add some description to this PR?! Thanks!

Didn't realize there is no description, just add it and thanks for the reminding.

[acloudiator]

Do we need to specify the user as "root"? If I'm not mistaken as long as the user have sudo privilege, it should be fine.
@mauriciovasquezbernal any thoughts?

[goldenrye]

the problem here is that without setting the USER environment variable, docker building will fail in this line silently,
install(CODE
"execute_process( COMMAND /bin/sh -c "mkdir -p /var/log/polycube && chown $ENV{USER} /var/log/polycube ")")

[acloudiator]

By default there is no polycubectl binary included in our official published pcn-k8s docker image: https://hub.docker.com/r/polycubenetwork/k8s-pod-network. We need this binary to help user to get more information of cubes running in the docker.

@goldenrye Why do we want this inside the k8s-pod-network, isn't the polycubectl under "polycubenetwork/polycube" image.

Try this and let us know if this what you want.

sudo docker run -it polycubenetwork/polycube /usr/local/bin/polycubectl

[goldenrye]

By default there is no polycubectl binary included in our official published pcn-k8s docker image: https://hub.docker.com/r/polycubenetwork/k8s-pod-network. We need this binary to help user to get more information of cubes running in the docker.

@goldenrye Why do we want this inside the k8s-pod-network, isn't the polycubectl under "polycubenetwork/polycube" image.

Try this and let us know if this what you want.

sudo docker run -it polycubenetwork/polycube /usr/local/bin/polycubectl

This command works but need add option "--net=host", but you have to run it in each node and won't be able to do that via kubectl like,
$ kubectl exec polycube-sddh5 -n kube-system polycubectl show cubes

polycube-sddh5 is a pod running in a slave node

[frisso]

This relates to bug report #198.

[asimpleidea]

Hi, in order to use polycubectl and check firewall lists I have always followed the quickstart part of the documentation on a worker node (which basically is @acloudiator's command):

docker pull polycubenetwork/polycube:latest
docker run  -it --rm --privileged --network host \
-v /lib/modules:/lib/modules:ro -v /usr/src:/usr/src:ro -v /etc/localtime:/etc/localtime:ro \
polycubenetwork/polycube:latest /bin/bash -c 'polycubed -d && /bin/bash'

It always worked fine.
Anyway, I see your point: entering inside a polycube pod like
kubectl exec -it polycube-pfzjn -n kube-system -c polycubed -- /bin/bash
and interacting with the polycubed of that node without leaving the k8s master could be a more convenient way than ssh-ing into the node and running a docker inside it.

[frisso]

To me this PR makes sense.
Just a question: is this causing the size of our dockers to grow? To me, this size is already a little bit big, so I would avoid further increases if not strictly needed.

[mauriciovasquezbernal]

I didn't enable this at that time because we're worried about the size of the image. I don't think this is an issue anymore, also the polycubectl size is about 10MB, what I think is negligible at this point.

[frisso]

@goldenrye It looks there's a consensus to add this PR. I would suggest to add a brief text in the "troubleshooting" section here, so that people are aware of this possibility:
https://github.com/polycube-network/polycube/blob/master/Documentation/components/k8s/pcn-kubernetes.rst

[palexster]

/lgtm