Multi-Node Kubernetes with KIND and Docker Desktop

You can run multi-node Linux Kubernetes clusters with full Linux command line support using the KIND project for Kubernetes. Lets walk through how you can set up a multi-node Kubernetes cluster on a single machine as a learning environment and CI/CD testing environment.


Video


Windows 10 - WSL2 - Docker

The best way to run Linux Docker containers on Windows 10 is with the WSL2 integration.  Docker will offer to enable WSL2 integration as part of its' installation if you are running a late enough version of Windows 10. 

All of the commands are the same from the windows prompt or from a unix prompt.  Open a Linux/Unix prompt if you have WSL2 or are running this on a mac. Open a GIT Bash prompt on Windows with Docker without WSL2

Install, Enable and Verify

  1. Open up a Linux command prompt.
  2. Change directory to a writable directory. The script below will need it.
Verify Kubernetes isn't already running
$ kubectl cluster-info

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
Unable to connect to the server: EOF
Install Kind in WSL2s linux using this script. Copy and paste it into your terminal window

cd /tmp
# Download the latest version of KinD
curl -Lo ./kind https://github.com/kubernetes-sigs/kind/releases/download/v0.10.0/kind-$(uname -s)-amd64
# Make the binary executable
chmod +x ./kind
# Move the binary to your executable path
sudo mv ./kind /usr/local/bin/
Verify kind is installed.
$ kind --version
kind version 0.10.0
Create a multi-node Kubernetes cluster named "dev" running virtual nodes as containers in a Docker Desktop instance. 
Run this file as a bash script.
It creates the cluster and changes the current cluster context is changed to kind-dev
# Create a config file for a 3 nodes cluster
cat << EOF > 3workers.yaml
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
  - role: control-plane
  - role: control-plane
  - role: worker
  - role: worker
  - role: worker
EOF
# Create a new cluster with the config file
# the context will be kind-dev
kind create cluster --name dev --config ./3workers.yaml
# Check how many nodes it created
The kind create cluster output should look something like 
$ kind create cluster --name dev --config ./3workers.yaml
Creating cluster "dev" ...
 ✓ Ensuring node image (kindest/node:v1.20.2) ðŸ–¼
 ✓ Preparing nodes ðŸ“¦ ðŸ“¦ ðŸ“¦ ðŸ“¦ ðŸ“¦
 ✓ Configuring the external load balancer ⚖️
 ✓ Writing configuration ðŸ“œ
 ✓ Starting control-plane ðŸ•¹️
 ✓ Installing CNI ðŸ”Œ
 ✓ Installing StorageClass ðŸ’¾
 ✓ Joining more control-plane nodes ðŸŽ®
 ✓ Joining worker nodes ðŸšœ
Set kubectl context to "kind-dev"
You can now use your cluster with:

kubectl cluster-info --context kind-dev

Have a nice day! ðŸ‘‹
Verify the cluster-info.  We should see both master and DNS servers
$ kubectl cluster-info --context kind-dev
Kubernetes master is running at https://127.0.0.1:32768
KubeDNS is running at https://127.0.0.1:32768/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
Verify the cluster has 3 worker nodes and 2 control plane nodes
$ kubectl get nodes
NAME                 STATUS   ROLES    AGE     VERSION
dev-control-plane    Ready    master   3m45s   v1.20.2
dev-control-plane2   Ready    master   3m16s   v1.20.2
dev-worker           Ready    <none>   2m16s   v1.20.2
dev-worker2          Ready    <none>   2m17s   v1.20.2
dev-worker3          Ready    <none>   2m19s   v1.20.2
 See that the 5 node Kubernetes cluster is actually implemented as 5 containers plus an haproxy container
$ docker ps
CCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
02a410c37431 kindest/haproxy:v20200708-548e36db "/docker-entrypoint.…" 25 minutes ago Up 25 minutes 127.0.0.1:44627->6443/tcp dev-external-load-balancer 79f3b52bceb9 kindest/node:v1.20.2 "/usr/local/bin/entr…" 25 minutes ago Up 25 minutes dev-worker 2b9c52767f50 kindest/node:v1.20.2 "/usr/local/bin/entr…" 25 minutes ago Up 25 minutes dev-worker2 2f9e27ba7ca9 kindest/node:v1.20.2 "/usr/local/bin/entr…" 25 minutes ago Up 25 minutes 127.0.0.1:40179->6443/tcp dev-control-plane 0b9df49f4739 kindest/node:v1.20.2 "/usr/local/bin/entr…" 25 minutes ago Up 25 minutes 127.0.0.1:45147->6443/tcp dev-control-plane2 a7a61e9e9418 kindest/node:v1.20.2 "/usr/local/bin/entr…" 25 minutes ago Up 25 minutes dev-worker3
Show existing Kubernetes contexts.  Notice the default context here is kind-dev
$ kubectl config get-contexts
CURRENT   NAME                 CLUSTER          AUTHINFO         NAMESPACE
          docker-desktop       docker-desktop   docker-desktop
          docker-for-desktop   docker-desktop   docker-desktop
*         kind-dev             kind-dev         kind-dev
See pretty much everything in all name spaces.
$ kubectl get all --all-namespaces
NAMESPACE            NAME                                             READY   STATUS    RESTARTS   AGE
kube-system          pod/coredns-6955765f44-558dk                     1/1     Running   0          5m15s
kube-system          pod/coredns-6955765f44-8kjvg                     1/1     Running   0          5m15s
kube-system          pod/etcd-dev-control-plane                       1/1     Running   0          5m24s
kube-system          pod/etcd-dev-control-plane2                      1/1     Running   0          4m42s
kube-system          pod/kindnet-2r2pp                                1/1     Running   0          3m58s
kube-system          pod/kindnet-6g4lg                                1/1     Running   0          5m14s
kube-system          pod/kindnet-8kwjr                                1/1     Running   0          4m
kube-system          pod/kindnet-mlhvw                                1/1     Running   1          4m57s
kube-system          pod/kindnet-w94fc                                1/1     Running   0          3m57s
kube-system          pod/kube-apiserver-dev-control-plane             1/1     Running   0          5m24s
kube-system          pod/kube-apiserver-dev-control-plane2            1/1     Running   0          3m57s
kube-system          pod/kube-controller-manager-dev-control-plane    1/1     Running   1          5m23s
kube-system          pod/kube-controller-manager-dev-control-plane2   1/1     Running   0          3m41s
kube-system          pod/kube-proxy-4vvl8                             1/1     Running   0          4m57s
kube-system          pod/kube-proxy-dmbhv                             1/1     Running   0          3m58s
kube-system          pod/kube-proxy-g2kn2                             1/1     Running   0          3m57s
kube-system          pod/kube-proxy-x5hlf                             1/1     Running   0          5m14s
kube-system          pod/kube-proxy-xxnbd                             1/1     Running   0          4m
kube-system          pod/kube-scheduler-dev-control-plane             1/1     Running   1          5m23s
kube-system          pod/kube-scheduler-dev-control-plane2            1/1     Running   0          3m32s
local-path-storage   pod/local-path-provisioner-7745554f7f-582tj      1/1     Running   1          5m15s

NAMESPACE     NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
default       service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP                  5m35s
kube-system   service/kube-dns     ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   5m24s

NAMESPACE     NAME                        DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                 AGE
kube-system   daemonset.apps/kindnet      5         5         5       5            5           <none>                        5m16s
kube-system   daemonset.apps/kube-proxy   5         5         5       5            5           beta.kubernetes.io/os=linux   5m24s

NAMESPACE            NAME                                     READY   UP-TO-DATE   AVAILABLE   AGE
kube-system          deployment.apps/coredns                  2/2     2            2           5m24s
local-path-storage   deployment.apps/local-path-provisioner   1/1     1            1           5m15s

NAMESPACE            NAME                                                DESIRED   CURRENT   READY   AGE
kube-system          replicaset.apps/coredns-6955765f44                  2         2         2       5m15s
local-path-storage   replicaset.apps/local-path-provisioner-7745554f7f   1         1         1       5m15s

API server and host access

The standard Docker Desktop Kuberentes endpoint doesn't work.  You must instead use the kubectl proxy which makes the Kubernetes API server visible outside the cluster.
$ kubectl proxy
Starting to serve on 127.0.0.1:8001
You can see the APIs available on the API server by pointing your browser at
 http://127.0.0.1:8001/

Delete the kind-created Kubernetes cluster and all assets

You can remove the cluster and everything else with
$ kind delete cluster --name dev
Deleting cluster "dev" ...
Verify the Kind managed Kubernetes nodes no longer exist.
$ docker ps
CONTAINER ID        IMAGE     COMMAND        CREATED        STATUS         PORTS          NAMES

Resources

Changes
  • May 16 2021 change version from 0.7 to 0.10 and container 1.17.x to 1.20.2

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