kubelet may detect GCE when running kind on GCE

[BenTheElder]

What happened: kubelet appears to have read /sys/class/dmi/id/product_name when running kind on GCE and detected "Google Compute Engine", it appears to fail if it can't talk to the metadata server.

What you expected to happen: Kubernetes should not "be in cloud mode" so to speak.

How to reproduce it (as minimally and precisely as possible): run a kind cluster on GCE

Anything else we need to know?:

Environment:

• kind version: (use kind version): 0.2.1
• Kubernetes version: (use kubectl version): 1.13.4
• Docker version: (use docker info):
• OS (e.g. from /etc/os-release):

[BenTheElder]

/assign

we should probably try to properly set cloud provider to none by default AND/OR always mount a special product_name by default.

current workaround:

# create a fake entry with our own "product name" to 
# mount at /sys/class/dmi/id/product_name
echo "kind" >./product_name

# create a kind cluster config equivalent to the current 
# default, but additionally mounting the above file
cat <<EOF >"./kind-config.yaml"
kind: Cluster
apiVersion: kind.sigs.k8s.io/v1alpha3
nodes:
- role: control-plane
  extraMounts:
  - containerPath: /sys/class/dmi/id/product_name
    hostPath: ${PWD}/product_name
EOF

# when creating a cluster be sure to use
# this config with  `--config=./kind-config.yaml`
kind create cluster --config=./kind-config.yaml

...

[BenTheElder]

This seems to be one of the blockers for #182.

[aojea]

kind remounts the /sys folder in the nodes as ro

kind/pkg/cluster/nodes/node.go

Line 221 in 161151a

if err := n.Command("mount", "-o", "remount,ro", "/sys").Run(); err != nil {

thus we can´t rewrite the file.

However, seems that kubernetes only uses the /sys/class/dmi/id/product_name to check if is running on a GCE VM
https://github.com/kubernetes/kubernetes/blob/716344fd7d68f92d9a16280be1feae0ffe122bb4/pkg/credentialprovider/gcp/metadata.go#L47 when using the GCP credential provider.

@BenTheElder I´m not familiar with the credential provider feature, is it possible to disable it?

[aojea]

Ben´s idea works
echo kind > /kind/product_name && mount -o ro,bind /kind/product_name /sys/class/dmi/id/product_name

[BenTheElder]

fixed by #461