Rootless

Starting with kind 0.11.0, Rootless Docker, Rootless Podman and Rootless nerdctl can be used as the node provider of kind.

Provider requirements 🔗︎

Docker: 20.10 or later
Podman: 3.0 or later
nerdctl: 1.7 or later

Host requirements 🔗︎

The host needs to be running with cgroup v2. Make sure that the result of the docker info command contains Cgroup Version: 2. If it prints Cgroup Version: 1, try adding GRUB_CMDLINE_LINUX="systemd.unified_cgroup_hierarchy=1" to /etc/default/grub and running sudo update-grub to enable cgroup v2.

Also, depending on the host configuration, the following steps might be needed:

Create /etc/systemd/system/[email protected]/delegate.conf with the following content, and then run sudo systemctl daemon-reload:
```
[Service]
Delegate=yes
```
(This is not enabled by default because “the runtime impact of [delegating the “cpu” controller] is still too high”. Beware that changing this configuration may affect system performance.)

Please note that:
- /etc/systemd/system/[email protected]/ directory needs to be created if not already present on your host
- If using Docker and it was already running when this step was done, a restart is needed for the changes to take effect systemctl --user restart docker
  systemctl --user restart docker
Create /etc/modules-load.d/iptables.conf with the following content:
```
ip6_tables
ip6table_nat
ip_tables
iptable_nat
```
If using podman, be aware that by default there is a limit to the number of pids that can be created. This can cause problems like nginx workers inside a container not spawning correctly.
- If you want to disable this limit, edit your containers.conf file (generally located in /etc/containers/containers.conf). Note that this could cause things like pid exhaustion to happen on the host machine. Alternatively, change 0 to your desired new limit:
```
[containers]
pids_limit = 0
```


`systemctl --user restart docker`

Restrictions 🔗︎

The restrictions of Rootless Docker apply to kind clusters as well.

e.g.

OverlayFS cannot be used unless the host is using kernel >= 5.11, or Ubuntu/Debian kernel
Cannot mount block storage
Cannot mount NFS

Creating a kind cluster with Rootless Docker 🔗︎

To create a kind cluster with Rootless Docker, just run:

$ export DOCKER_HOST=unix://${XDG_RUNTIME_DIR}/docker.sock
$ kind create cluster

Creating a kind cluster with Rootless Podman 🔗︎

To create a kind cluster with Rootless Podman, just run:

$ KIND_EXPERIMENTAL_PROVIDER=podman kind create cluster

On some distributions, you might need to use systemd-run to start kind into its own cgroup scope:

$ systemd-run --scope --user kind create cluster

$ systemd-run --scope --user -p "Delegate=yes" kind create cluster

If you still get the error running kind with rootless provider requires setting systemd property "Delegate=yes" even with host requirements configured.

Creating a kind cluster with Rootless nerdctl 🔗︎

Note: containerd v1.7+ is required

To create a kind cluster with nerdctl, just run:

$ KIND_EXPERIMENTAL_PROVIDER=nerdctl kind create cluster

Tips 🔗︎

To enable OOM watching, allow dmesg by running sysctl -w kernel.dmesg_restrict=0.