Quickly Set Up a Standalone Kubernetes Cluster Using Docker

With the popularity of cloud-native technologies such as containerization, microservices, service mesh, service orchestration, and DevOps, we need to keep up with the times. So how do we get on board? At this point, we need a tool that is easy to run locally and works with Kubernetes, allowing us to easily create a standalone Kubernetes cluster in a virtual machine on your laptop, facilitating our daily development and learning with Kubernetes. Now, let's easily set up a more realistic K8s environment.

Tool Recommendations#

For local experimentation, various Kubernetes implementations can be used to run Kubernetes clusters, such as:

Kind (https://kind.sigs.k8s.io/)
Minikube (https://minikube.sigs.k8s.io/docs/)
MicroK8s (https://microk8s.io/)
Online K8s Experience (https://labs.play-with-k8s.com/)
Dockerized (https://github.com/y0ngb1n/dockerized) Recommended my personal project, welcome to Star

The goal of using any of the above tools is to quickly run a local learning Kubernetes cluster, among which my personal favorite is Kind.

Setting Up K8s Cluster#

Next, let's try creating a standalone Kubernetes cluster with Kind and Minikube.

First, Install `kubectl`#

Regardless of which tool you use, you need to correctly install the kubectl Kubernetes command-line tool first; otherwise, you won't be able to execute kubectl commands after installing Kind, Minikube, and other environments.

Installation Documentation: https://kubernetes.io/zh/docs/tasks/tools/#kubectl

Create K8s Cluster Using Kind#

kind is a tool for running local Kubernetes clusters using Docker container “nodes”.

Install `kind`#

Kind provides various installation methods, supporting the following:

On macOS via Homebrew
On macOS via MacPorts
On Windows via Chocolatey
Installing From Release Binaries
Installing From Source

Here, we will install it in a Linux environment using the Installing From Release Binaries method:

curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.11.1/kind-linux-amd64
chmod +x ./kind
# mv ./kind /some-dir-in-your-PATH/kind

Create K8s Cluster#

kind create cluster
# kind delete cluster

Verify Installation Environment#

🐋️ ~ kind get clusters
kind

Create K8s Cluster Using Minikube#

Install `minikube`#

Choose the installation method for different environments, refer to https://minikube.sigs.k8s.io/docs/start/

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

In a domestic network environment, use the following command to automatically use Alibaba Cloud services to support the minikube environment configuration, refer to https://developer.aliyun.com/article/221687

minikube start --image-mirror-country='cn'
# minikube delete

Verify Installation Environment#

🐋️ ~ minikube status
minikube
type: Control Plane
host: Running
kubelet: Running
apiserver: Running
kubeconfig: Configured

Start the K8s dashboard, refer to https://minikube.sigs.k8s.io/docs/handbook/dashboard/

minikube dashboard
# or
minikube dashboard --url

View the list of extensions supported by minikube, refer to https://minikube.sigs.k8s.io/docs/handbook/deploying/

minikube addons list

Verify K8s Cluster#

🐋️ ~ kubectl version
Client Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.1", GitCommit:"5e58841cce77d4bc13713ad2b91fa0d961e69192", GitTreeState:"clean", BuildDate:"2021-05-12T14:18:45Z", GoVersion:"go1.16.4", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.3", GitCommit:"c92036820499fedefec0f847e2054d824aea6cd1", GitTreeState:"clean", BuildDate:"2021-10-27T18:35:25Z", GoVersion:"go1.16.9", Compiler:"gc", Platform:"linux/amd64"}

# Check the current pointed k8s environment; kind/minikube installation will automatically modify kubectl configuration
🐋️ ~ kubectl config current-context
kind-kind

# If there are multiple k8s environments locally, you can switch manually
🐋️ ~ kubectl config use-context minikube
Switched to context "minikube".

# Check server nodes
🐋️ ~ kubectl get no
NAME       STATUS   ROLES                  AGE   VERSION
minikube   Ready    control-plane,master   36m   v1.22.3

🐋️ ~ kubectl get nodes -o wide
NAME       STATUS   ROLES                  AGE   VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION     CONTAINER-RUNTIME
minikube   Ready    control-plane,master   15m   v1.22.3   192.168.49.2   <none>        Ubuntu 20.04.2 LTS   5.4.0-42-generic   docker://20.10.8

# View k8s cluster information
🐋️ ~ kubectl cluster-info
Kubernetes control plane is running at https://192.168.49.2:8443
CoreDNS is running at https://192.168.49.2:8443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

First Experience with K8s#

Quick Taste#

# Start a single instance of nginx
🐋️ ~ kubectl create deployment nginx-depl --image=nginx

# View running instances
🐋️ ~ kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
nginx-depl-5c8bf76b5b-zw8ms   1/1     Running   0          70s

# Forward a local port 8080 to Pod port 80
🐋️ ~ kubectl port-forward nginx-depl-5c8bf76b5b-zw8ms 8080:80

# Access locally
🐋️ ~ curl 127.0.0.1:8080

# Clean up the instance
🐋️ ~ kubectl delete deployment nginx-depl

A Small Trial#

nginx-pod.yml

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  containers:
    - name: nginx
      image: nginx

nginx-svc.yml

apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  ports:
    - name: http
      port: 80
      targetPort: 80
      nodePort: 31080
  selector:
    app: nginx
  type: NodePort

Execute the command:

# One-click publish, start the instance
🐋️ ~ kubectl apply -f .

# Debug Pod
🐋️ ~ kubectl describe pod nginx
🐋️ ~ kubectl port-forward nginx 8080:80

# Debug Service
🐋️ ~ kubectl describe svc nginx-svc
🐋️ ~ kubectl port-forward service/nginx-svc 8080:80

# Clean up the instance
🐋️ ~ kubectl delete -f .

Notes#

You need to correctly install kubectl first
Port-Forward allows local access to Pod, limited to local debugging environments, such as curl 127.0.0.1:8080
When using Service for reverse proxy, you need to access using the K8s cluster's IP, use kubectl get nodes -o wide to view the K8s cluster's IP
Service is a mechanism provided by K8s for reverse proxy, responsible for reverse routing + load balancing
NodePort is a type of Service that can expose the Service to the external network
NodePort range is 30000~32767
Label is K8s's labeling mechanism
Selector is the routing selection mechanism in K8s
K8s clusters deployed using Kind or Minikube run nodes based on containers rather than the host machine; when using Service for reverse proxy, kube-proxy only takes effect in the node container, verify this by using docker exec -it kind-control-plane bash, not directly mapped on the host machine

K8s Troubleshooting Guide#

a-visual-guide-on-troubleshooting-kubernetes-deployments

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