helm needs socat on the nodes of the k8s cluster

[sebgoa]

But cluster nodes, may not have socat installed by default.

For instance coreOS stable does not ship socat:

coreos/bugs#1114

This is a problem since helm use a port-forwarding technique to connect to tiller.

ps: there might be the same issue with nsenter

[maratoid]

That's not so much a Helm problem, as a Kubernetes problem (https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/dockertools/docker_manager.go#L1167)

Personally I ended up bootstrapping all of our CoreOs nodes with socat in /opt/bin and adding /opt/bin to kubelet service PATH environment variable with a systemd drop-in.

[technosophos]

Yeah, I think we are going to have to bump this up to the CoreOS/Kubernetes level. However, I'm leaving the issue open here while we track what's going on upstream.

[sebgoa]

Yes, I did not mean to say it was a Helm problem. But we as Helm are assuming that k8s cluster nodes will have socat...which may not be true.

Honestly I think protobuf is cool, but for exposing API outside k8s it makes things a bit tricky.

[rimusz]

@maratoid where did you get the socat binary? I tried the statically built from https://github.com/andrew-d/static-binaries but it almost crashes VM with a very high CPU usage when I do helm install some chart

[maratoid]

@rimusz try https://github.com/andrew-d/static-binaries

[rimusz]

@maratoid this is what I was testing with helm v2, socat from there works fine only with kubectl port-forward but with helm socat goes nuts of using a lot of CPU and helm install just hangs

[technosophos]

FWIW, in Slack, dhilipkumars hit this issue when running Kubernetes on Ubuntu locally. The fix was to export HELM_HOST to the k8s API address/port. We need a FAQ or something to document issues like this.

[philips]

CoreOS doesn't ship socat but the container that the kubelet runs in has ./usr/bin/socat. What is the issue with that socat? How do I reproduce?

[philips]

cc @pbx0 @aaronlevy @derekparker

[rimusz]

@philips if kubernetes e.g. is run via go binaries then kubectl port-forward and helm v2 install chart do not work

[sebgoa]

@philips the issue I faced was the following. I have a coreOS k8s cluster with coreOS 899.
./helm init deploy the tiller server fine, but by default the helm client tries to setup a port-forward to the tiller pod. port-forward uses socat, hence helm fails talking to tiller because socat is not found. I personally setup a NodePort service and set my HELM_HOST to that port, but it is insecure.

[philips]

@rimusz OK, CoreOS Linux won't support this setup because kubelet has a number of dependencies that aren't. Please run kubelet in a container.

@Runseb I am able to successfully use helm v2.0.0-alpha.4 with CoreOS Linux and Kubernetes v1.4-beta0:

$ helm install docs/examples/alpine
Error: file "docs/examples/alpine" not found
$ cd
$ cd src/k8s.io/he
heapster/ helm/
$ cd src/k8s.io/helm/
$ helm install docs/examples/alpine
washing-squid
Last Deployed: Fri Sep  9 00:08:03 2016
Namespace: default
Status: DEPLOYED

Resources:
==> v1/Pod
NAME                      READY     STATUS              RESTARTS   AGE
washing-squid-my-alpine   0/1       ContainerCreating   0          1s

[sebgoa]

@philips which version of coreOS ?

[philips]

@Runseb alpha using the hyperkube kubelet container