Now everywhere is kubernetes, below is my practice of using kubeadmhttps://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/ to build up my first k8s cluster and deployment, time to go!
Step 1). Provision two virtual machines.
I use Ubuntu-1604 and each server has 4CPU, 8.0GMem, 50GDisk.
cat /proc/version Linux version 4.4.0-148-generic (buildd@lgw01-amd64-031) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.10) ) #174-Ubuntu SMP Tue May 7 12:20:14 UTC 2019Step 2). Install kubelet kubeadm kubectland docker at both nodes.
I’m not at US and I use below mirror to install it quickly. ssh the server first. Then run below.
apt-get update && apt-get install -y apt-transport-https
curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubelet kubeadm kubectl
apt install docker.ioAdd DNS server to /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4Step 3). Setup master node.
ssh to the master node. Run kubeadm init Below messages show it is successful.
Your Kubernetes control-plane has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 10.0.13.122:6443 --token bm31hs.xxx \
--discovery-token-ca-cert-hash sha256:xxxAdd private IP and host into /etc/hosts e.g. 10.0.13.122 kvm-019646
Run below.
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/configStep 4). Setup worker node.
Add private IP and host into /etc/hosts e.g. 10.0.11.147 kvm-019647
ssh to the worker node. Run the kubeadm join
kubeadm join 10.0.13.122:6443 --token bm31hs.xxx \
--discovery-token-ca-cert-hash sha256:xxxCool, I get below messages.
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.Step 5). Check at master node.
kubectl get nodes
NAME STATUS ROLES AGE VERSION
kvm-019646 NotReady master 18m v1.15.0
kvm-019647 NotReady <none> 9s v1.15.0Install calico or weave to enable network and network policies at Kubernetes clusters.
kubectl apply -f https://git.io/weave-kube-1.6Then you could get Ready status.
kubectl get nodes
NAME STATUS ROLES AGE VERSION
kvm-019646 Ready master 40m v1.15.0
kvm-019647 Ready <none> 21m v1.15.0Bravo, the k8s cluster is setup!
Step 6). Try the deployment.
Deploy below nginx deployment. Save below into nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.8
ports:
- containerPort: 80Apply the nginx.yaml
kubectl apply -f nginx.yaml
deployment.apps/nginx-deployment createdTo access it from other boxes, deploy a service with NodePort Save below into a yaml file and apply it.
apiVersion: v1
kind: Service
metadata:
name: mysvc
namespace: default
spec:
ports:
- port: 80
protocol: TCP
selector:
app: nginx
type: NodePortGet the node port.
port=$(kubectl get svc mysvc -o jsonpath={.spec.ports[0].nodePort})
echo $portAt my case, 31559 is returned. So I could use master node IP and the port to access it. Open http://9.111.139.68:31559/ from web browser. I will see.
Run kubectl get pods --all-namespaces could see all pods.
Cool, I have deployed the k8s cluster and also a nginx deployment, well done!
Jingjing 