Deploy php & nginx app using multi-node kubernetes cluster

Initialise kube control-panel node

kubeadm  init --pod-network-cidr=192.168.0.0/16

Run the following commands to start using the cluster:

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

Setup Kube network policy using WeaveNet

sudo mkdir -p /var/lib/weave
head -c 16 /dev/urandom | shasum -a 256 | cut -d" " -f1 | sudo tee /var/lib/weave/weave-passwd
kubectl create secret -n kube-system generic weave-passwd --from-file=/var/lib/weave/weave-passwd
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

Create a Kubernetes dashboard

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0/aio/deploy/recommended.yaml
kubectl apply -f dashboard-config/service_account.yaml
kubectl apply -f dashboard-config/cluster_role.yaml 

Access the dashboard

#Open a local port and spin up a proxy server between local and kube server
ssh -L 8001:127.0.0.1:8001 user@master-node-ip
kubectl proxy

#Acces the dashboard by pointing to the following link
http://127.0.0.1:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/#/login

#Now, grab the access token from the service account we created earlier
kubectl -n kubernetes-dashboard describe secret $(kubectl -n kubernetes-dashboard get secret | grep admin-user | awk '{print $1}')

Join the worker nodes to the master

Note: if you have forgotten to note down the original join command from kubeadm init, run the following to print the join command.

kubeadm token create --print-join-command

Setup php & nginx server using nfs for multi-node kube cluster

Setup a nfs server on master node:

1. Install nfs server

   sudo apt install nfs-kernel-server

2. create a nfs shared directory:

   mkdir -p /srv/nfs/kubedata

3. Grant nfs share access

   vi /etc/exports
   
   #configure ip and access types
   /srv/nfs/kubedata 192.168.1.1/24(rw,no_root_squash)
   

4. systemctl retsart nfs-server

Create a persistent volume

  kubectl apply -f nfs_pv.yml  
  kubectl apply -f nfs_pvc.yml
  
  #list the created pv's(should return a volume named nfs-pv with a claim nfs-pvc attached to it)
  kubectl get pv 

Setup nginx deployment & service:

1. create a nginx config map

   kubectl apply -f config/nginx_configMap.yaml

2. Create a nginx deployment

   kubectl apply -f config/nginx_deployment.yaml

3. Create a nginx service

   ---

   Specify one of your node's ip as the external ip for the nginx service.

      apiVersion: v1
      kind: Service
      metadata:
        name: nginx
        labels:
          tier: backend
      spec:
        selector:
          app: nginx
          tier: backend
        ports:
        - protocol: TCP
          port: 80
        externalIPs:
        - {external_ip}
   

   kubectl apply -f config/nginx_deployment.yaml

Setup php deployment & service:

1. Create a deployment

   kubectl apply -f config/php_deployment.yaml

   This will deploy a php app with index.php file created using busybox image before the app is initiated.

      initContainers:
      - name: install
        image: busybox
        volumeMounts:
        - name: nfs-share
          mountPath: /var/www
        command: ['sh', '-c', 'echo "<?php echo phpinfo();" > /var/www/index.php']
   

2. Create a service

   kubectl apply -f config/php_service.yaml

Now the deployed app can by accessed by pointing your browser to {external_ip} specified for nginx service

http://{external_ip}

WIN!