kind Cheatsheet

Last Updated: 2023-09-18

# Create clusters.
$ kind create cluster --name test-cluster

# Get clusters.
$ kind get clusters
test-cluster

# Get nodes of a cluster.
$ kind get nodes --name test-cluster
test-cluster-control-plane

# Get kubeconfig and use it to talk to the cluster.
$ kind get kubeconfig --name test-cluster > ~/test-cluster-kubeconfig
$ kubectl --kubeconfig  ~/test-cluster-kubeconfig ...
$ k9s --kubeconfig  ~/test-cluster-kubeconfig

$ kind export kubeconfig --name test-cluster
Set kubectl context to "kind-test-cluster"
# `current-context` of `~/.kube/config` is updated to `kind-test-cluster`

# Export logs
$ kind export logs --name test-cluster
Exporting logs for cluster "test-cluster" to: /path/to/log

# load images; calls `ctr images import` under the hood.
$ kind load image-archive

# Get IP address
$ docker container inspect test-cluster-control-plane \
 --format '{{ .NetworkSettings.Networks.kind.IPAddress }}'

# Delete clusters.
$ kind delete cluster --name test-cluster

# Check kind version
$ kind version

Check inside the control plane node.

# Get the container name of the control plane.
$ docker ps
CONTAINER ID   IMAGE                  ... NAMES
2ff461dc6529   kindest/node:v1.xx.x   ... test-cluster-control-plane

# Get inside the container.
$ docker exec -it test-cluster-control-plane bash
# List images on the control plane node.
root@test-cluster-control-plane:/# crictl images
# List running containers.
root@test-cluster-control-plane:/# crictl ps
# List running processes
root@test-cluster-control-plane:/# ps aux

Notes about control plane processes:

built-in components as expected: kube-apiserver, kube-scheduler, kube-controller-manager, kube-proxy, etcd, coredns, etc
containerd as a CRI implementation to deal with Pods and containers. No docker inside the control plane docker container.

Networking

By default Kind clusters use a bridge network named kind (check by docker network ls). This can be overriden by setting KIND_EXPERIMENTAL_DOCKER_NETWORK.

$ KIND_EXPERIMENTAL_DOCKER_NETWORK=test-network kind create cluster --name test-cluster-with-test-network

# List networks
$ docker network ls
NETWORK ID     NAME           DRIVER    SCOPE
02ef0832c25e   test-network   bridge    local

# Check details of the network
$ docker network inspect test-network

# Clean up unused networks
$ docker network prune

The number of networks you can create is limited by /etc/docker/daemon.json. You may see this error:

Error response from daemon: could not find an available, non-overlapping IPv4 address pool among the defaults to assign to the network

https://github.com/kubernetes-sigs/kind/blob/3610f606516ccaa88aa098465d8c13af70937050/pkg/cluster/internal/providers/docker/provider.go#L73

Create clusters with multiple nodes

$ cat <<EOF | kind create cluster --name test-cluster-with-multiple-nodes --config -
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: worker
- role: worker
EOF

$ kind get nodes --name test-cluster-with-multiple-nodes
test-cluster-with-multiple-nodes-worker
test-cluster-with-multiple-nodes-worker2
test-cluster-with-multiple-nodes-control-plane

Shell Completion

# bash
$ source <(kind completion bash)
$ echo "source <(kind completion bash)" >> ~/.bashrc

# zsh
$ source <(kind completion zsh)
# or
$ echo "source <(kind completion zsh)" >> ~/.zshrc

Create a kind cluster with rootless docker

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

Dependencies

Providers: Rootless Docker and Rootless Podman.
kind uses kubeadm to configure cluster nodes.

Provider

Provider is used to perform cluster operations.

A Provider has an internal provider + a logger

Node Image

Base image: https://github.com/kubernetes-sigs/kind/blob/main/images/base/Dockerfile

Node image (pkg/build/nodeimage/) is built upon base image

node image = base image (basic utilities like systemd, certificates, mount, etc.) + k8s packages and binaries (e.g. kubeadm, kubectl, kubelet)