#!/bin/bash
###############################################################################
#
# This script creates an NFS Persistent Volumes(PV) and also claims that PV
# with a PVC of the same size.
# Note: PVs can be claimed by one PVC at a time
#
###############################################################################
#
# Requirements:
#  - NFS server with directory to use as path for mount
#  - Access to an existing Kubernetes Cluster
#  - Kubectl installed and configured on machine running script
#
###############################################################################
#
# The script expects a few variables which are needed to define PV's and PVC's
#  mode     ReadWriteOnce|ReadOnlyMany|ReadWriteMany
#           Access Mode used by NFS normally uses ReadWriteMany
#           Default: ReadWriteMany
#  name     The name of the PV and PVC that will be used by the Kubernetes
#           system to refer to PV/PVC
#           Default: "placeholder"
#  nfs_ip   Server IP for NFS server that will be used
#           Default: "NFS-Server"
#  nfs_path Path of the directory that will be mounted from NFS server
#           Default: "/san/dir"
#  ns       Namespace under which to create the mounts on the cluster
#           Default: "openbmc"
#  reclaim  recycle|delete|retain
#           The policy, defines what occurs when claim on PV is released, can
#           be either: recycle, delete, or retain.
#           Default: "Retain"
#  size     The size of the volume, numeric value followed by Gi or Mi
#           Default: "10Gi"
#
# Note: Kubernetes Systems permissions vary by implementation
#       some will require permissions to create PV's or PVC's
#
###############################################################################

mode=${mode:-ReadWriteMany}
name=${name:-placeholder}
nfs_ip=${nfs_ip:-NFS-Server}
nfs_path=${nfs_path:-/san/dir}
ns=${ns:-openbmc}
reclaim=${reclaim:-Retain}
size=${size:-10Gi}

# Generate the PV
pv=$(cat << EOF
apiVersion: v1
kind: PersistentVolume
metadata:
  labels:
    app: ${name}
  name: ${name}
  namespace: ${ns}
spec:
  accessModes:
  - ${mode}
  capacity:
    storage: ${size}
  nfs:
    path: ${nfs_path}
    server: ${nfs_ip}
  persistentVolumeReclaimPolicy: ${reclaim}
EOF
)

# create the volume
if [ -z $(kubectl get pv --namespace=${ns} | grep '^'${name}' ' | cut -d " " -f1) ];then
  echo "Creating Persistent Volume ${name}"
  kubectl create -f - <<< "${pv}"
else
  echo "Persistent Volume already Exists"
fi


# Generate the PVC
pvc=$(cat << EOF
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: ${name}
  namespace: ${ns}
spec:
  accessModes:
  - ${mode}
  resources:
    requests:
      storage: ${size}
  selector:
    matchLabels:
      app: ${name}
EOF
)

# create PVC's to bind the PV's
if [ -z $(kubectl get pvc --namespace=${ns} | grep '^'${name}' ' | cut -d " " -f1) ];then
  echo "Creating Persistent Volume Claim ${name}"
  kubectl create -f - <<< "${pvc}"
else
  echo "Persistent volume claim already exists."
fi