Kind is an amazing tool for running test clusters locally as it runs in a container which makes it lightweight and easy to run throw-away clusters for testing purposes.

Download KUBECTL

We can download kubectl from the Official Docs

Create a kubernetes cluster

In this guide we will run two clusters side by side so we can demonstrate cluster access.
Create two clusters:

kind create cluster --name dev --image kindest/node:v1.23.5
kind create cluster --name prod --image kindest/node:v1.23.5

See cluster up and running:

kubectl get nodes
NAME                  STATUS   ROLES                  AGE     VERSION
prod-control-plane   Ready    control-plane,master   2m12s   v1.23.5

Understanding the KUBECONFIG

Default location of the kubeconfig file is in <users-directory>/.kube/config

kind: Config
apiVersion: v1
clusters:
 - list of clusters (addresses \ endpoints) 
users:
 - list of users (thing that identifies us when accessing a cluster [certificate]) 
contexts:
 - list of contexts ( which user and cluster to use when running commands)

Commands to interact with kubeconfig are kubectl config.
Key commands are telling kubectl which context to use

kubectl config current-context
kubectl config get-contexts
kubectl config use-context <name>

You can also tell your kubectl to use different config files.
This is useful to keep your production config separate from your development ones

Set the $KUBECONFIG environment variable to a path:

#linux
export KUBECONFIG=<path>

#windows 
$ENV:KUBECONFIG="C:\Users\aimve\.kube\config"

We can export seperate configs using kind
This is possible with cloud based clusters as well:

kind --name dev export kubeconfig --kubeconfig C:\Users\aimve\.kube\dev-config 

kind --name prod export kubeconfig --kubeconfig C:\Users\aimve\.kube\prod-config 

#switch to prod
$ENV:KUBECONFIG="C:\Users\aimve\.kube\prod-config"
kubectl get nodes

Working with Kubernetes resources

Now that we have cluster access, next we can read resources from the cluster with the kubectl get command.

Namespaces

Most kubernetes resources are namespace scoped:

kubectl get namespaces

By default, kubectl commands will run against the default namespace

List resources in a namespace

kubectl get <resource>

kubectl get pods
kubectl get deployments
kubectl get services
kubectl get configmaps
kubectl get secrets
kubectl get ingress

Create resources in a namespace

We can create a namespace with the kubectl create command:

kubectl create ns example-apps

Let's create a couple of resources:


kubectl -n example-apps create deployment webserver --image=nginx --port=80
kubectl -n example-apps get deploy
kubectl -n example-apps get pods

kubectl -n example-apps create service clusterip webserver --tcp 80:80
kubectl -n example-apps get service
kubectl -n example-apps port-forward svc/webserver 80
# we can access http://localhost/

kubectl -n example-apps create configmap webserver-config --from-file config.json=./kubernetes/kubectl/config.json
kubectl -n example-apps get cm

kubectl -n example-apps create secret generic webserver-secret --from-file secret.json=./kubernetes/kubectl/secret.json
kubectl -n example-apps get secret

Working with YAML

As you can see we can create resources with kubectl but this is only for basic testing purposes. Kubernetes is a declarative platform, meaning we should provide it what to create instead of running imperative line-by-line commands.

We can also get the YAML of pre-existing objects in our cluster with the -o yaml flag on the get command

Let's output all our YAML to a yaml folder:

kubectl -n example-apps get cm webserver-config -o yaml > .\kubernetes\kubectl\yaml\config.yaml
kubectl -n example-apps get secret webserver-secret -o yaml > .\kubernetes\kubectl\yaml\secret.yaml
kubectl -n example-apps get deploy webserver -o yaml > .\kubernetes\kubectl\yaml\deployment.yaml
kubectl -n example-apps get svc webserver -o yaml > .\kubernetes\kubectl\yaml\service.yaml

Create resources from YAML files

The most common and recommended way to create resources in Kubernetes is with the kubectl apply command.
This command takes in declarative YAML files.

To show you how powerful it is, instead of creating things line-by-line, we can deploy all our infrastructure with a single command.

Let's deploy a Wordpress CMS site, with a back end MySQL database.
This is a snippet taken from my How to learn Kubernetes video:

kubectl create ns wordpress-site
kubectl -n wordpress-site apply -f ./kubernetes/tutorials/basics/yaml/

We can checkout our site with the port-forward command:

kubectl -n wordpress-site get svc

NAME        TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
mysql       ClusterIP   10.96.146.75   <none>        3306/TCP   17s
wordpress   ClusterIP   10.96.157.6    <none>        80/TCP     17s

kubectl -n wordpress-site port-forward svc/wordpress 80

Clean up

kind delete cluster --name dev
kind delete cluster --name prod