Dockershim deprecation does NOT impact kind.  πŸ³

If you already use kind you've actually been testing your workloads on containerd!

While kind uses docker or podman on your host, it uses CRI / containerd "inside" the nodes and does not use dockershim.

Carry on and be KiND! ❀️

Known Issues

Having problems with kind? This guide covers some known problems and solutions / workarounds.

It may additionally be helpful to:

Contents πŸ”—︎

Kubectl Version Skew πŸ”—︎

You may have problems interacting with your kind cluster if your client(s) are skewed too far from the kind node version. Kubernetes only supports limited skew between clients and the API server.

This is a issue that frequently occurs when running kind alongside Docker For Mac.

This problem is related to a bug in docker on macOS

If you see something like the following error message:

$ kubectl edit deploy -n kube-system kubernetes-dashboard
error: SchemaError(io.k8s.api.autoscaling.v2beta1.ExternalMetricStatus): invalid object doesn't have additional properties

You can check your client and server versions by running:

kubectl version

If there is a mismatch between the server and client versions, you should install a newer client version.

If you are using Mac, you can install kubectl via homebrew by running:

brew install kubernetes-cli

And overwrite the symlinks created by Docker For Mac by running:

brew link --overwrite kubernetes-cli

Older Docker Installations πŸ”—︎

kind is known to have issues with Kubernetes 1.13 or lower when using Docker versions:

And possibly other old versions of Docker.

With these versions you must use Kubernetes >= 1.14, or more ideally upgrade Docker instead.

kind is tested with a recent stable docker-ce release.

Docker Installed with Snap πŸ”—︎

If you installed Docker with snap, it is likely that docker commands do not have access to $TMPDIR. This may break some kind commands which depend on using temp directories (kind build ...).

Currently a workaround for this is setting the TEMPDIR environment variable to a directory snap does have access to when working with kind. This can for example be some directory under $HOME.

Failure to build node image πŸ”—︎

Building kind's node image may fail due to running out of memory on Docker for Mac or Docker for Windows. See kind#229.

If you see something like this:

    cmd/kube-scheduler
    cmd/kube-proxy
/usr/local/go/pkg/tool/linux_amd64/link: signal: killed
!!! [0116 08:30:53] Call tree:
!!! [0116 08:30:53]  1: /go/src/k8s.io/kubernetes/hack/lib/golang.sh:614 kube::golang::build_some_binaries(...)
!!! [0116 08:30:53]  2: /go/src/k8s.io/kubernetes/hack/lib/golang.sh:758 kube::golang::build_binaries_for_platform(...)
!!! [0116 08:30:53]  3: hack/make-rules/build.sh:27 kube::golang::build_binaries(...)
!!! [0116 08:30:53] Call tree:
!!! [0116 08:30:53]  1: hack/make-rules/build.sh:27 kube::golang::build_binaries(...)
!!! [0116 08:30:53] Call tree:
!!! [0116 08:30:53]  1: hack/make-rules/build.sh:27 kube::golang::build_binaries(...)
make: *** [all] Error 1
Makefile:92: recipe for target 'all' failed
!!! [0116 08:30:54] Call tree:
!!! [0116 08:30:54]  1: build/../build/common.sh:518 kube::build::run_build_command_ex(...)
!!! [0116 08:30:54]  2: build/release-images.sh:38 kube::build::run_build_command(...)
make: *** [quick-release-images] Error 1
ERRO[08:30:54] Failed to build Kubernetes: failed to build images: exit status 2
Error: error building node image: failed to build kubernetes: failed to build images: exit status 2
Usage:
  kind build node-image [flags]

Flags:
      --base-image string   name:tag of the base image to use for the build (default "kindest/base:v20181203-d055041")
  -h, --help                help for node-image
      --image string        name:tag of the resulting image to be built (default "kindest/node:latest")
      --kube-root string    Path to the Kubernetes source directory (if empty, the path is autodetected)
      --type string         build type, default is docker (default "docker")

Global Flags:
      --loglevel string   logrus log level [panic, fatal, error, warning, info, debug] (default "warning")

error building node image: failed to build kubernetes: failed to build images: exit status 2

Then you may try increasing the resource limits for the Docker engine on Mac or Windows.

It is recommended that you allocate at least 8GB of RAM to build Kubernetes.

Open the Preferences menu.

Go to the Advanced settings page, and change the settings there, see changing Docker's resource limits.

Setting 8Gb of memory in Docker for Mac

Setting 8Gb of memory in Docker for Windows

Failing to properly start cluster πŸ”—︎

This issue is similar to a failure while building the node image. If the cluster creation process was successful but you are unable to see any Kubernetes resources running, for example:

$ docker ps
CONTAINER ID        IMAGE                  COMMAND                  CREATED              STATUS              PORTS                      NAMES
c0261f7512fd        kindest/node:v1.12.2   "/usr/local/bin/entr…"   About a minute ago   Up About a minute   0.0.0.0:64907->64907/tcp   kind-1-control-plane
$ docker exec -it c0261f7512fd /bin/sh
# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
#

or kubectl being unable to connect to the cluster,

$ kind export kubeconfig
$ kubectl cluster-info

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
Unable to connect to the server: EOF

Then as in kind#156, you may solve this issue by claiming back some space on your machine by removing unused data or images left by the Docker engine by running:

docker system prune

And / or:

docker image prune

You can verify the issue by exporting the logs (kind export logs) and looking at the kubelet logs, which may have something like the following:

Dec 07 00:37:53 kind-1-control-plane kubelet[688]: I1207 00:37:53.229561     688 eviction_manager.go:340] eviction manager: must evict pod(s) to reclaim ephemeral-storage
Dec 07 00:37:53 kind-1-control-plane kubelet[688]: E1207 00:37:53.229638     688 eviction_manager.go:351] eviction manager: eviction thresholds have been met, but no pods are active to evict

Failure to Create Cluster with Cgroups v2 πŸ”—︎

Support for Cgroups v2 was introduced in Kubernetes 1.19 (see release notes). Accordingly, only Kubernetes versions >= 1.19 are supported on hosts using Cgroups v2.

You can verify that you are hitting this issue by exporting the logs (kind export logs) and looking at the kubelet logs, which may have something like the following:

Feb 23 08:39:04 kind-control-plane kubelet[3031]: W0223 08:39:04.644052    3031 server.go:616] failed to get the kubelet's cgroup: mountpoint for cpu not found.  Kubelet system container metrics may be missing.
Feb 23 08:39:04 kind-control-plane kubelet[3031]: F0223 08:39:04.644296    3031 server.go:274] failed to run Kubelet: mountpoint for  not found

Pod errors due to “too many open files” πŸ”—︎

This may be caused by running out of inotify resources. Resource limits are defined by fs.inotify.max_user_watches and fs.inotify.max_user_instances system variables. For example, in Ubuntu these default to 8192 and 128 respectively, which is not enough to create a cluster with many nodes.

To increase these limits temporarily run the following commands on the host:

sudo sysctl fs.inotify.max_user_watches=524288
sudo sysctl fs.inotify.max_user_instances=512

To make the changes persistent, edit the file /etc/sysctl.conf and add these lines:

fs.inotify.max_user_watches = 524288
fs.inotify.max_user_instances = 512

Docker permission denied πŸ”—︎

When using kind, we assume that the user you are executing kind as has permission to use docker. If you initially ran Docker CLI commands using sudo, you may see the following error, which indicates that your ~/.docker/ directory was created with incorrect permissions due to the sudo commands.

WARNING: Error loading config file: /home/user/.docker/config.json
open /home/user/.docker/config.json: permission denied

To fix this problem, either follow the docker's docs manage docker as a non root user, or try to use sudo before your commands (if you get command not found please check this comment about sudo with kind).

Docker init daemon config πŸ”—︎

Please make sure that when you use kind, you can't have "init": true in your /etc/docker/daemon.json because that will cause /sbin/init to show the following cryptic message Couldn't find an alternative telinit implementation to spawn. This has to to with /sbin/init not running as process id 1.

Windows Containers πŸ”—︎

Docker Desktop for Windows supports running both Linux (the default) and Windows Docker containers.

kind for Windows requires Linux containers. To switch between Linux and Windows containers see this page.

Windows containers are not like Linux containers and do not support running docker in docker and therefore cannot support kind.

Non-AMD64 Architectures πŸ”—︎

KIND does not currently ship pre-built images for non-amd64 architectures. In the future we may, but currently demand has been low and the cost to build has been high.

To use kind on other architectures, you need to first build a base image and then build a node image.

Run images/base/build.sh and then taking note of the built image name use kind build node-image --base-image=kindest/base:tag-i-built.

There are more details about how to do this in the Quick Start guide.

Unable to pull images πŸ”—︎

When using named KIND instances you may sometimes see your images failing to pull correctly on pods. This will usually manifest itself with the following output when doing a kubectl describe pod my-pod

Failed to pull image "docker.io/my-custom-image:tag": rpc error: code = Unknown desc = failed to resolve image "docker.io/library/my-custom-image:tag": no available registry endpoint: pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed

If this image has been loaded onto your kind cluster using the command kind load docker-image my-custom-image then you have likely not provided the name parameter.

Re-run the command this time adding the --name my-cluster-name param:

kind load docker-image my-custom-image --name my-cluster-name

Chrome OS πŸ”—︎

Kubernetes does not work in the Chrome OS Linux sandbox.

Please see the upstream issue https://bugs.chromium.org/p/chromium/issues/detail?id=878034

For previous discussion see: https://github.com/kubernetes-sigs/kind/issues/763

AppArmor πŸ”—︎

If your host has AppArmor enabled you may run into moby/moby/issues/7512.

You will likely need to disable apparmor on your host or at least any profile(s) related to applications you are trying to run in KIND.

See Previous Discussion: kind#1179

IPv6 Port Forwarding πŸ”—︎

Docker assumes that all the IPv6 addresses should be reachable, hence doesn't implement port mapping using NAT moby#17666.

You will likely need to use Kubernetes services like NodePort or LoadBalancer to access your workloads inside the cluster via the nodes IPv6 addresses.

See Previous Discussion: kind#1326

Fedora πŸ”—︎

Firewalld πŸ”—︎

On Fedora 32 firewalld moved to nftables backend by default. This seems to be incompatible with Docker, leading to KIND cluster nodes not being able to reach each other.

You can work around this by changing the FirewallBackend in the /etc/firewalld/firewalld.conf file from nftables to iptables and restarting firewalld.

sed -i /etc/firewalld/firewalld.conf 's/FirewallBackend=.*/FirewallBackend=iptables/'
systemctl restart firewalld

See #1547 (comment) and Docker and Fedora 32 article

SELinux πŸ”—︎

On Fedora 33 an update to the SELinux policy causes kind create cluster to fail with an error like

docker: Error response from daemon: open /dev/dma_heap: permission denied.

Although the policy has been fixed in Fedora 34, the fix has not been backported to Fedora 33 as of June 28, 2021. Putting SELinux in permissive mode (setenforce 0) is one known workaround. This disables SELinux until the next boot. For more details, see kind#2296.