3 node local kubernetes cluster by centos7

Vagrant kubernetes 3 node cluster with ubuntu 20.04

---

On Host (with linux)

kubectl installation:

$ curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/

$ sudo vi /etc/hosts

#---------------------------------------------------------------------
# Kubernetes cluster
#---------------------------------------------------------------------

192.168.0.10 master.k8s master
192.168.0.11 node1.k8s node1
192.168.0.12 node2.k8s node2

$ vagrant plugin install vagrant-hostmanager

$ mkdir ~/vagrant-kubernetes-centos-7 && cd ~/vagrant-kubernetes-centos-7

$ git clone https://github.com/webmakaka/vagrant-kubernetes-3-node-cluster-centos7 .

$ cd latest

$ vagrant box update

$ vagrant up

$ vagrant status
Current machine states:

master.k8s                running (virtualbox)
node1.k8s                 running (virtualbox)
node2.k8s                 running (virtualbox)

Copy kubernetes config for manage kubernetes cluster remotely

$ mkdir -p ~/.kube

// root password: kubeadmin
$ scp root@master:/etc/kubernetes/admin.conf ~/.kube/config

$ kubectl version --short
Client Version: v1.20.1
Server Version: v1.20.1

$ kubectl get nodes
NAME         STATUS   ROLES                  AGE     VERSION
master.k8s   Ready    control-plane,master   8m48s   v1.20.1
node1.k8s    Ready    <none>                 5m41s   v1.20.1
node2.k8s    Ready    <none>                 2m24s   v1.20.1

Get Additional Inforamtion

$ kubectl get po -n kube-system
NAME                                 READY   STATUS    RESTARTS   AGE
coredns-74ff55c5b-czjk8              1/1     Running   0          9m11s
coredns-74ff55c5b-jfg5w              1/1     Running   0          9m11s
etcd-master.k8s                      1/1     Running   0          9m18s
kube-apiserver-master.k8s            1/1     Running   0          9m18s
kube-controller-manager-master.k8s   1/1     Running   0          9m18s
kube-flannel-ds-amd64-6bvbh          1/1     Running   0          3m5s
kube-flannel-ds-amd64-97v5g          1/1     Running   0          9m11s
kube-flannel-ds-amd64-cgsns          1/1     Running   0          6m22s
kube-proxy-j92xg                     1/1     Running   0          9m11s
kube-proxy-kbjn6                     1/1     Running   0          3m5s
kube-proxy-xl9mb                     1/1     Running   0          6m22s
kube-scheduler-master.k8s            1/1     Running   0          9m18s

$ kubectl cluster-info
Kubernetes control plane is running at https://192.168.0.10:6443
KubeDNS is running at https://192.168.0.10:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

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

$ kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused   
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused   
etcd-0               Healthy     {"health":"true"}                                                                             

Possible check

$ cat <<EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nodejs-cats-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nodejs-cats-app
  template:
    metadata:
      labels:
        app: nodejs-cats-app
        env: dev
    spec:
      containers:
      - name: nodejs-cats-app
        image: webmakaka/cats-app
        imagePullPolicy: Always
        ports:
        - containerPort: 8080
EOF

$ cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Service
metadata:
  name: nodejs-cats-app-nodeport
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 8080
    nodePort: 30123
  selector:
    app: nodejs-cats-app
EOF

$ kubectl get pods
NAME                              READY   STATUS    RESTARTS   AGE
nodejs-cats-app-56cc7754f-gznk2   1/1     Running   0          2m57s
nodejs-cats-app-56cc7754f-lsqxk   1/1     Running   0          2m57s
nodejs-cats-app-56cc7754f-qx59d   1/1     Running   0          2m57s

$ kubectl get svc
NAME                       TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes                 ClusterIP   10.96.0.1       <none>        443/TCP        12m
nodejs-cats-app-nodeport   NodePort    10.97.149.237   <none>        80:30123/TCP   3m54s

Should work

http://192.168.0.11:30123
http://192.168.0.12:30123

// Delete created resources
// $ kubectl delete svc nodejs-cats-app-nodeport
// $ kubectl delete deployment nodejs-cats-app

Original src:
https://github.com/justmeandopensource/kubernetes

---

Marley

Any questions in english: Telegram Chat
Любые вопросы на русском: Телеграм чат