NFS and Microk8s

Change default StorageClass

kubectl patch storageclass local-path -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
kubectl patch storageclass microk8s-hostpath -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'

Clients Quick

apt install -y nfs-client
mkdir -p /opt/local-path-provisioner

vi /etc/fstab
nas1:/<your mount point> /opt/local-path-provisioner nfs4  _netdev,auto  0  0
mount -a
ls /opt/local-path-provisioner/

Using a script

It is important to understand this file. Client ip addresses are highly trusted and controlled kubernetes nodes.

Do not run files on nas directory it should only be used as a file store.

#!/usr/bin/env bash
set -e
if [ "$#" -ne 3 ]; then
  echo "Usage: $0 <uuid> <nfs node type server/client> \"<client ips>\""
  echo "Example: $0 28a1f1f8-e686-11eb-bf45-7f257ca7269b server \"10.x.x.x 10.x.x.y 10.x.x.z\""
  exit
fi

uuid=$1
node_type=$2
client_ips=$3
server_host=nas
server_mnt=/$uuid
server_net_mnt="${server_host}:${server_mnt}"
client_mnt=/opt/local-path-provisioner


if ! [[ $uuid =~ ^\{?[A-F0-9a-f]{8}-[A-F0-9a-f]{4}-[A-F0-9a-f]{4}-[A-F0-9a-f]{4}-[A-F0-9a-f]{12}\}?$ ]]; then
  echo "E: Invalid uuid format."
exit
fi


install_client(){
  echo Installing client.
  sudo sed -i "/$uuid/d" /etc/fstab
  grep $server_mnt /etc/fstab || echo "$server_net_mnt $client_mnt nfs" | sudo tee -a /etc/fstab
  sudo mkdir -p $client_mnt && sudo chmod 0755 $client_mnt
  sudo apt install -y nfs-client  # nfs-common
  sudo mount -a
}


install_server(){
  echo Installing server.
  sudo apt install nfs-kernel-server
  sudo mkdir -p $server_mnt && sudo chmod 0755 $server_mnt
  sudo mv /etc/exports /etc/exports.bkp
  for ip in $client_ips; do
    # risky echo "$server_mnt    $ip(rw,sync,no_subtree_check,insecure,no_root_squash)" | sudo tee -a /etc/exports
    # http://fullyautolinux.blogspot.com/2015/11/nfs-norootsquash-and-suid-basic-nfs.html?m=1
    echo "$server_mnt    $ip(rw,sync,no_subtree_check,insecure,root_squash)" | sudo tee -a /etc/exports
  done
  sudo chmod 0644 /etc/exports
  sudo systemctl reload nfs-server
}


install_localpathprov(){
  # https://github.com/rancher/local-path-provisioner
  kubectl get sc | grep ^local-path && return
  echo "Installing rancher local-path-provisioner in 10 seconds."
  sleep 10
  kubectl apply -f https://raw.githubusercontent.com/rancher/local-path-provisioner/master/deploy/local-path-storage.yaml
  kubectl create -f https://raw.githubusercontent.com/rancher/local-path-provisioner/master/examples/pvc/pvc.yaml
  kubectl create -f https://raw.githubusercontent.com/rancher/local-path-provisioner/master/examples/pod/pod.yaml
}


if [[ "$node_type" == "server" ]]; then
  install_server
elif [[ "$node_type" == "client" ]]; then
  install_client
  install_localpathprov
else
  echo "E: Unsupported node_type."
fi

Testing

mkdir ~/mnt
sudo mount -t nfs $server_net_mnt ~/mnt
echo hi > ~/mnt/hi.txt
cat ~/mnt/hi.txt

https://www.linuxtechi.com/configure-nfs-persistent-volume-kubernetes/