Question: Can I run Kubernetes in Docker?. If you want to test Kubernetes without any commitment, the easiest and quickest way is to use Docker Containers. This method doesn’t have many prerequisites and is not resource-intensive. Any decent Linux machine which can run Docker is all that’s required.
We had earlier covered other methods that can help you get a running Lightweight Kubernetes Cluster on Linux. See below.
For Docker Lovers, this method is another option you can explore. The setup has been done on CentOS 7 & Ubuntu Server. But the process should be similar for other Linux distributions.
Step 1: Install Docker
Start by installing Docker runtime engine, this will be used to run all Kubernetes services. Our guides below should be of great help.
- Install Docker and Docker Compose on Linux
- How to install Docker CE on Ubuntu / Debian / CentOS
- How to install Docker on Fedora
For quick install you can use below commands to install Docker:
curl -fsSL get.docker.com -o get-docker.sh
sudo bash get-docker.shConfirm if docker is installed properly by running:
$ docker version
Client: Docker Engine - Community
Version: 20.10.8
API version: 1.41
Go version: go1.16.6
Git commit: 3967b7d
Built: Fri Jul 30 19:54:27 2021
OS/Arch: linux/amd64
Context: default
Experimental: true
Server: Docker Engine - Community
Engine:
Version: 20.10.8
API version: 1.41 (minimum version 1.12)
Go version: go1.16.6
Git commit: 75249d8
Built: Fri Jul 30 19:52:33 2021
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.4.9
GitCommit: e25210fe30a0a703442421b0f60afac609f950a3
runc:
Version: 1.0.1
GitCommit: v1.0.1-0-g4144b63
docker-init:
Version: 0.19.0
GitCommit: de40ad0Step 2: Install kind Tool on Linuc / macOS
kind is a tool for running local Kubernetes clusters using Docker container “nodes”. kind is primarily designed for testing Kubernetes 1.11+, initially targeting the conformance tests.
Linux:
curl -s https://api.github.com/repos/kubernetes-sigs/kind/releases/latest| grep browser_download_url | grep kind-linux-amd64 | cut -d '"' -f 4 | wget -qi -
chmod a+x kind-linux-amd64
sudo mv kind-linux-amd64 /usr/local/bin/kindmacOS:
# Using brew
brew install kind
# Using Curl
curl -s https://api.github.com/repos/kubernetes-sigs/kind/releases/latest| grep browser_download_url | grep darwin-arm64 | cut -d '"' -f 4 | wget -qi -Windows:
choco install kindCheck version installed.
$ kind version
kind v0.11.1 go1.16.4 linux/amd64Step 4: Run local Kubernetes clusters using Docker container “nodes”.
We now have all requirements satisfied. We should be ready to create a local Kubernetes cluster running on Docker containers.
sudo kind create clusterYou should get output like this:
kind create cluster | sudo tee -a kind_output.txt
Creating cluster "kind" ...
• Ensuring node image (kindest/node:v1.15.0) 🖼 ...
✓ Ensuring node image (kindest/node:v1.15.0) 🖼
• Preparing nodes 📦 ...
✓ Preparing nodes 📦
• Creating kubeadm config 📜 ...
✓ Creating kubeadm config 📜
• Starting control-plane 🕹️ ...
✓ Starting control-plane 🕹️
• Installing CNI 🔌 ...
✓ Installing CNI 🔌
• Installing StorageClass 💾 ...
✓ Installing StorageClass 💾
Cluster creation complete. You can now use the cluster with:
export KUBECONFIG="$(kind get kubeconfig-path --name="kind")"
kubectl cluster-infoYou can view a running container with docker ps command.
# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d5bd9c025fe6 kindest/node:v1.15.0 "/usr/local/bin/entr…" 27 minutes ago Up 27 minutes 34213/tcp, 127.0.0.1:34213->6443/tcp
kind-control-planeStep 5: Install Kubectl command-line tool
To access the Kubernetes cluster from the command line, you need kubectl command line tool. This can be easily installed by running the command:
curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectlMake the kubectl binary executable.
chmod +x ./kubectlMove the binary into your PATH.
sudo mv ./kubectl /usr/local/bin/kubectlTest to ensure the version you installed is up-to-date:
$ kubectl version
Client Version: version.InfoMajor:"1", Minor:"15", GitVersion:"v1.15.2", GitCommit:"f6278300bebbb750328ac16ee6dd3aa7d3549568", GitTreeState:"clean", BuildDate:"2019-08-05T09:23:26Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"For other systems, refer to the official kubectl installation guide.
Configure Autocompletion:
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc For zsh users, run:
source <(kubectl completion zsh)
echo "if [ $commands[kubectl] ]; then source <(kubectl completion zsh); fi" >> ~/.zshrcStep 6: Configure kubectl
Create Kubectl configuration directory:
mkdir ~/.kubeCreate kubectl configuration symlink to the Kind generated config file.
ln -s `kind get kubeconfig-path --name="kind"` ~/.kube/configTest kubectl configuration.
$ kubectl cluster-info
Kubernetes master is running at https://127.0.0.1:34213
KubeDNS is running at https://127.0.0.1:34213/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
$ kubectl config get-clusters
NAME
kind
$ kubectl config get-contexts
CURRENT NAME CLUSTER AUTHINFO NAMESPACE
* [email protected] kind kubernetes-admin
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kind-control-plane Ready master 30m v1.15.0
$ kubectl get namespaces
NAME STATUS AGE
default Active 31m
kube-node-lease Active 31m
kube-public Active 31m
kube-system Active 31m
$ kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-5c98db65d4-q7k7w 1/1 Running 0 31m
coredns-5c98db65d4-svdpf 1/1 Running 0 31m
etcd-kind-control-plane 1/1 Running 0 30m
kindnet-nv5gq 1/1 Running 1 31m
kube-apiserver-kind-control-plane 1/1 Running 0 30m
kube-controller-manager-kind-control-plane 1/1 Running 0 30m
kube-proxy-4n874 1/1 Running 0 31m
kube-scheduler-kind-control-plane 1/1 Running 0 30mYou’re on the right track to Learning Kubernetes using your local cluster. I recommend you visit K8s Concepts page to use interactive guides available.
