`kind` : Kubernetes in Docker | Releases

TL;DR

kind is a tool for running local Kubernetes clusters using Docker container(s) as "node(s)". The app was designed for testing Kubernetes itself, but is widely used for local development or CI.

bash kind-install.sh

kind-install.sh

Install

unset arch
[[ $(uname -m) == x86_64 ]]  && arch=amd64
[[ $(uname -m) == aarch64 ]] && arch=arm64
# https://github.com/kubernetes-sigs/kind/releases
v=0.24.0
to=/usr/local/bin/kind
type -t kind && kind --version |grep $v || {
    [[ $arch ]] && { 
        sudo curl -sSLo $to https://kind.sigs.k8s.io/dl/v$v/kind-linux-$arch && 
        sudo chmod +x $to && 
        kind --version |grep $v || exit 1
    }
}

Useage

# Create K8s cluster 
kind create cluster 
kind create cluster --name kind-other
kind create cluster --config custom-kind-config.yaml

# Create K8s cluster of a declared version 
img=kindest/node:v1.29.4@sha256:3abb816a5b1061fb15c6e9e60856ec40d56b7b52bcea5f5f1350bc6e2320b6f8
cat <<-EOH |kind create cluster --config=-
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  image: $img
- role: worker
  image: $img 
EOH

# Build kind from source (of declared version) and then create K8s cluster
ver=0.23.0
go install sigs.k8s.io/kind@v$ver && kind create cluster

kind create cluster also creates ~/.kube file(s).
kind delete cluster also purges ~/.kube/config
Configuration section has more of that.

# Inspect
kind get clusters

# Use K8s-API client 
kubectl cluster-info # --context kind-kind
kubectl get ds,deploy,pod,cm,svc -A
kubectl get node -o wide
kubectl apply -f appx.yaml

# Load image(s) into cluster "node(s)" 
kind load docker-image $img_1 $img_2 --name kind-2
# Load image archive(s) into cluster "node(s)" 
kind load image-archive $img_1_tarball --name $cluster

# List images of a "node"
node=kind-control-plane
docker exec -it $node crictl images

# Teardown
kind delete cluster

Configuration (YAML)

Multi-node cluster

# Multi-node : 1 control-plane nodes and 2 worker nodes
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
name: kind                      # Default
networking:
  podSubnet: "10.244.0.0/16"    # Default
networking:
  serviceSubnet: "10.96.0.0/12" # Default
networking:
  kubeProxyMode: "ipvs"         # iptables (default), nftables (v1.31+), or ipvs
nodes:
- role: control-plane
  kubeadmConfigPatches:
  - |
    kind: InitConfiguration
    nodeRegistration:
      kubeletExtraArgs:
        node-labels: "my-label=true"  
  kubeadmConfigPatches:
  - |
    kind: ClusterConfiguration
    apiServer:
        extraArgs:
          enable-admission-plugins: NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook 
- role: worker
- role: worker

Multi-node HA cluster

# Multi-node HA : 3 control and 3 workers
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: control-plane
- role: control-plane
- role: worker
- role: worker
  labels:
    tier: backend 
  extraMounts:
  - hostPath: /path/at/host
    containerPath: /whereever
- role: worker
  labels:
    tier: frontend

Map extra ports to host : extraPortMappings

# Map extra ports to host 
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  extraPortMappings:
  - containerPort: 80
    hostPort: 80
    listenAddress: "0.0.0.0"    # Optional, defaults to "0.0.0.0"
    protocol: udp               # Optional, defaults to tcp

Set the (K8s) version

That versions page implies kind does not support all K8s versions. Also note that version numbers of kind and kubernetes do not match. For example, kind v0.23.0 defaults to K8s v1.30.0 (kindest/node:v1.30.0) .

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  image: kindest/node:v1.29.4@sha256:3abb816a5b1061fb15c6e9e60856ec40d56b7b52bcea5f5f1350bc6e2320b6f8
- role: worker
  image: kindest/node:v1.29.4@sha256:3abb816a5b1061fb15c6e9e60856ec40d56b7b52bcea5f5f1350bc6e2320b6f8

kind supports multi-node (including HA) clusters
kind supports building Kubernetes release builds from source
- support for make / bash or docker, in addition to pre-published builds
kind supports Linux, macOS and Windows
kind is a CNCF certified conformant Kubernetes installer

kind requires one of: docker, podman, nerdctl.

If rootless (podman's default configuration), then "kind create cluster" will fail. The workaround for rootless-user environments is known to cause system-performance issues.

RHEL 8+ has podman already installed, and it (purposefully) conflicts with docker, so installing (switching to) the latter requires flags --allowerasing and (typically) --nobest :

How to install Docker @ RHEL 8+

(This does not install the unnecessary Docker Desktop.)

# Prep to install Docker
sudo dnf install -y dnf-utils
[[ -f /etc/yum.repos.d/docker-ce.repo ]] \
    || sudo dnf config-manager --add-repo https://download.docker.com/linux/rhel/docker-ce.repo
sudo dnf makecache 

# Latest stable version
pkgs='docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin'
# Else a declared version 
## 1. Find it
yum list docker-ce --showduplicates |sort -r
  # docker-ce.x86_64     3:27.0.3-1.el9     docker-ce-stable
  # ...
  # docker-ce.x86_64     3:26.1.4-1.el9     docker-ce-stable
  # docker-ce.x86_64     3:26.1.3-1.el9     docker-ce-stable
  # ...
## 2. Select it
arch=x86_64
ver=27.0.3-1.el9
pkgs="docker-ce-$ver.$arch docker-ce-cli-$ver.$arch containerd.io docker-buildx-plugin docker-compose-plugin"

# Install Docker Engine (the server), client apps, and all their dependencies
sudo dnf install --allowerasing --nobest $pkgs

Docker v1.12+ has containerd as its default (CRI-compliant) container runtime, yet Docker is not CRI-compliant, so Kubernetes requires a shim (dockershim) to interface with Docker regardless. It is not advised to use Docker with Kubernetes in production.

`ingress-nginx` : Install / Configure / Test

Ingress NGINX Controller

Docs/Configs per context:

Create a cluster configured for ingress (controller) at ports 80 (HTTP) and 443 (HTTPS)

@ `Ubuntu [14:20:12] [1] [#0] /s/DEV/devops/infra/kubernetes/kind`

kind create cluster --config kind-config-ingress-nginx.yaml

@ kind-config-ingress-nginx.yaml

Deploy Ingress NGINX Controller (ingress-nginx) using manifest configured for kind

# kind-specific deployment manifest
url=https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/kind/deploy.yaml
# Install it
kubectl apply -f $url
# Verify it
kubectl wait --namespace ingress-nginx \
    --for=condition=ready pod \
    --selector=app.kubernetes.io/component=controller \
    --timeout=90s

Save the ingress-nginx controller installation manifest

curl -sSLo ingress-nginx-kind.yaml $url

@ ingress-nginx-kind.yaml

Usage : Deploy a test app

☩ k apply -f https://kind.sigs.k8s.io/examples/ingress/usage.yaml
pod/foo-app created
service/foo-service created
pod/bar-app created
service/bar-service created
Warning: path /foo(/|$)(.*) cannot be used with pathType Prefix
Warning: path /bar(/|$)(.*) cannot be used with pathType Prefix
ingress.networking.k8s.io/example-ingress created

☩ curl localhost/foo/hostname
foo-app

☩ curl localhost/bar/hostname
bar-app

Despite warnings, it works.
Docker config may require use node's INTERNAL-IP (Docker bridge network) instead of localhost. Obtain from either:
- ip=$(k get node kind-control-plane -o jsonpath='{.status.addresses[0].address}')
- ip=$(docker network inspect kind |jq -Mr .[].Containers[].IPv4Address)
```
☩ curl $ip/bar/hostname
```

Save the usage manifest

curl -sSLo ingress-nginx-kind-usage-oem.yaml https://kind.sigs.k8s.io/examples/ingress/usage.yaml

@ ingress-nginx-kind-usage-oem.yaml
@ ingress-nginx-kind-usage.yaml
- Modify hostnames, from foo-app to foo (similary for bar), and allow apply to stack-test namespace.

kind : Kubernetes in Docker | Releases