HOW to install kubernetes on Virtual BOX with Centos 7 : Working perfectly

Setting up the Kubernetes Master

This setup will work on Virtual host labs:

The following actions will be executed on the Kubernetes Master.

1. Disable swap

   swapoff -a
   

2. Edit: /etc/fstab

   vi /etc/fstab
   

3. Comment out swap

   #/root/swap swap swap sw 0 0
   

4. Add the Kubernetes repo

   cat << EOF > /etc/yum.repos.d/kubernetes.repo
   [kubernetes]
   name=Kubernetes
   baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
   enabled=1
   gpgcheck=1
   repo_gpgcheck=1
   gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
   exclude=kube*
   EOF
   

5. Disable SELinux

   setenforce 0
   

6. Permanently disable SELinux:

   vi /etc/selinux/config
   

7. Change enforcing to disabled

   SELINUX=disabled
   

8. Install Kubernetes 

   yum install -y kubelet kubeadm kubectl  kubernetes-cni-0.6.0 --disableexcludes=kubernetes
   

9. Start and enable the Kubernetes service

   systemctl start kubelet && systemctl enable kubelet
   

10. Create the k8s.conf file:

    cat << EOF >  /etc/sysctl.d/k8s.conf
    net.bridge.bridge-nf-call-ip6tables = 1
    net.bridge.bridge-nf-call-iptables = 1
    EOF
    sysctl --system
    

11. Assuming your Network is 192.168.1.1/16

12. Initialize Kubernetes

    
     kubeadm init --pod-network-cidr=192.168.1.0/16
    
    
    

13. Copy admin.conf to your home directory

    mkdir -p $HOME/.kube
    cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
    chown $(id -u):$(id -g) $HOME/.kube/config

14. Install calico

    curl \
       https://docs.projectcalico.org/v3.5/getting-started/kubernetes/installation/hosted/kubernetes-datastore/calico-networking/1.7/calico.yaml \
       -O
    

       kubectl apply -f calico.yaml

15. Then reolad kubelete

    systemctl restart kubelet
    

Setting up the Kubernetes Worker nodes

Now that the setup for the Kubernetes master is complete, we will begin the process of configuring the worker node. The following actions will be executed on the Kubernetes worker.

1. Disable swap

   swapoff -a
   

2. Edit: /etc/fstab

   vi /etc/fstab
   

3. Comment out swap

   #/root/swap swap swap sw 0 0
   

4. Add the Kubernetes repo

   cat << EOF > /etc/yum.repos.d/kubernetes.repo
   [kubernetes]
   name=Kubernetes
   baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
   enabled=1
   gpgcheck=1
   repo_gpgcheck=1
   gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
   exclude=kube*
   EOF
   

5. Disable SELinux

   setenforce 0
   

6. Permanently disable SELinux:

   vi /etc/selinux/config
   

7. Change enforcing to disabled

   SELINUX=disabled
   

8. Install Kubernetes 

   yum install -y kubelet kubeadm kubectl kubernetes-cni --disableexcludes=kubernetes
   

9. Start and enable the Kubernetes service

   systemctl start kubelet && systemctl enable kubelet
   

10. Create the k8s.conf file:

    cat << EOF >  /etc/sysctl.d/k8s.conf
    net.bridge.bridge-nf-call-ip6tables = 1
    net.bridge.bridge-nf-call-iptables = 1
    EOF
    sysctl --system
    

11. Use the join token to add the Worker Node to the cluster:

    kubeadm join < MASTER_IP >:6443 --token < TOKEN > --discovery-token-ca-cert-hash sha256:< HASH >

12. On the master node, test to see if the cluster was created properly.

13. Get a listing of the nodes:

    kubectl get nodes

14.  Note : If your token is expired  issue below command  :: kubeadm token create