Kind on btrfs

[jdonszelmann]

What happened:

kind create cluster

errors with the following error:

docker run error: command "docker run --hostname kind-control-plane --name kind-control-plane --label io.x-k8s.kind.role=control-plane --privileged --security-opt seccomp=unconfined --security-opt apparmor=unconfined --tmpfs /tmp --tmpfs /run --volume /var --volume /lib/modules:/lib/modules:ro --detach --tty --label io.x-k8s.kind.cluster=kind --volume /dev/mapper /dev/mapper --publish=127.0.0.1:39139:6443/TCP kindest/node:v1.17.2@sha256:59df31fc61d1da5f46e8a61ef612fa53d3f9140f82419d1ef1a6b9656c6b737c" failed with error: exit status 125
ERROR: failed to create cluster: docker run error: command "docker run --hostname kind-control-plane --name kind-control-plane --label io.x-k8s.kind.role=control-plane --privileged --security-opt seccomp=unconfined --security-opt apparmor=unconfined --tmpfs /tmp --tmpfs /run --volume /var --volume /lib/modules:/lib/modules:ro --detach --tty --label io.x-k8s.kind.cluster=kind --volume /dev/mapper /dev/mapper --publish=127.0.0.1:39139:6443/TCP kindest/node:v1.17.2@sha256:59df31fc61d1da5f46e8a61ef612fa53d3f9140f82419d1ef1a6b9656c6b737c" failed with error: exit status 125
exit status 1

And doesn't create a cluster.

What you expected to happen:

It should just set up the cluster

How to reproduce it (as minimally and precisely as possible):

git clone https://github.com/kubernetes-sigs/kind kind
cd kind
go run main.go create cluster

Anything else we need to know?:

this issue is related to #1416 where I also commented.
There seems to be a bug introduced in #1464 . In this commit you added

	if mountDevMapper() {
		args = append(args, "--volume", "/dev/mapper", "/dev/mapper")
	}

But I think this has to be

	if mountDevMapper() {
		args = append(args, "--volume", "/dev/mapper:/dev/mapper")
	}

Which results in the following command:

docker run --hostname kind-control-plane --name kind-control-plane --label io.x-k8s.kind.role=control-plane --privileged --security-opt seccomp=unconfined --security-opt apparmor=unconfined --tmpfs /tmp --tmpfs /run --volume /var --volume /lib/modules:/lib/modules:ro --detach --tty --label io.x-k8s.kind.cluster=kind --volume /dev/mapper:/dev/mapper --publish=127.0.0.1:46023:6443/TCP kindest/node:v1.17.2@sha256:59df31fc61d1da5f46e8a61ef612fa53d3f9140f82419d1ef1a6b9656c6b737c

instead of

docker run --hostname kind-control-plane --name kind-control-plane --label io.x-k8s.kind.role=control-plane --privileged --security-opt seccomp=unconfined --security-opt apparmor=unconfined --tmpfs /tmp --tmpfs /run --volume /var --volume /lib/modules:/lib/modules:ro --detach --tty --label io.x-k8s.kind.cluster=kind --volume /dev/mapper /dev/mapper --publish=127.0.0.1:46023:6443/TCP kindest/node:v1.17.2@sha256:59df31fc61d1da5f46e8a61ef612fa53d3f9140f82419d1ef1a6b9656c6b737c

being run

(sorry, one char difference. It's a colon after /dev/mapper)

It might also be useful to know that I run btrfs as a root filesystem (btrfs-progs v5.6)

Environment:

• kind version: (use kind version): kind v0.8.0-alpha go1.14.2 linux/amd64
• Docker version: (use docker info): 19.03.8-ce
• OS (e.g. from /etc/os-release): Arch linux (Linux 5.6.5-arch3-1)

[aojea]

🤦

[aojea]

@jonay2000 can you confirm that running this command manually works ?

docker run --hostname kind-control-plane --name kind-control-plane --label io.x-k8s.kind.role=control-plane --privileged --security-opt seccomp=unconfined --security-opt apparmor=unconfined --tmpfs /tmp --tmpfs /run --volume /var --volume /lib/modules:/lib/modules:ro --detach --tty --label io.x-k8s.kind.cluster=kind --volume /dev/mapper:/dev/mapper --publish=127.0.0.1:46023:6443/TCP kindest/node:v1.17.2@sha256:59df31fc61d1da5f46e8a61ef612fa53d3f9140f82419d1ef1a6b9656c6b737c

I can't test it and prefer to not introduce an error again,

[jdonszelmann]

Can confirm. Works flawlessly

[jdonszelmann]

Thanks for the quick response :)