#!/bin/bash

# From https://gist.github.com/yuanying/3aa7d59dcce65470804ab43def646ab6

IMAGE="ubuntu:18.04"
COMMAND="/bin/bash"
SUFFIX=$(date +%s | shasum | base64 | fold -w 10 | head -1 | tr '[:upper:]' '[:lower:]')

usage_exit() {
    echo "Usage: $0 [-c command] [-i image] PVC ..." 1>&2
    exit 1
}

if [ "$#" -ne 1 ]; then
    usage_exit
fi

while getopts i:h OPT
do
    case $OPT in
        i)  IMAGE=$OPTARG
            ;;
        c)  COMMAND=$OPTARG
            ;;
        h)  usage_exit
            ;;
        \?) usage_exit
            ;;
    esac
done
shift $(($OPTIND - 1))

VOL_MOUNTS=""
VOLS=""
COMMA=""

for i in $@
do
  VOL_MOUNTS="${VOL_MOUNTS}${COMMA}{\"name\": \"${i}\",\"mountPath\": \"/pvcs/${i}\"}"
  VOLS="${VOLS}${COMMA}{\"name\": \"${i}\",\"persistentVolumeClaim\": {\"claimName\": \"${i}\"}}"
  COMMA=","
done

kubectl run -it --rm --restart=Never --image=${IMAGE} pvc-mounter-${SUFFIX} --overrides "
{
  \"spec\": {
    \"hostNetwork\": true,
    \"containers\":[
      {
        \"args\": [\"${COMMAND}\"],
        \"stdin\": true,
        \"tty\": true,
        \"name\": \"pvc\",
        \"image\": \"${IMAGE}\",
        \"volumeMounts\": [
          ${VOL_MOUNTS}
        ]
      }
    ],
    \"volumes\": [
      ${VOLS}
    ]
  }
}
" -- ${COMMAND}