Adapted a couple of encrypted ephemeral disk examples for simple temp storage on mesos-worker nodes (e.g. with Spark)

gistfile1.txt

#!/bin/bash

#
# WARNING:  This will wipe and encrypt the device given.  For Mesos workers,
# this is run on EVERY BOOT so you will constantly lose existing data.
#

# I have based this script on the following links:
# https://github.com/matthew-lucidchart/aws-ephemeral-mounts/blob/master/boot_luks.sh
# http://nineofclouds.blogspot.ca/2013/10/how-to-use-lvm-and-luks-with-ebs-volumes.html
#
# This is intended to be put on a host by Ansible.  The Ansible variable "ephemeral_dev" must
# be populated, e.g. "xvdb".

KEYDIR=/var/cache/ephemeral-mount
MAPPED_DEV=/dev/mapper/ephemeral

/bin/mkdir -p "$KEYDIR"
/bin/chmod 700 "$KEYDIR"

# Make key:
/bin/dd if=/dev/urandom of="$KEYDIR/ephemeral.key" bs=4k count=1
# encrypt the device:
/sbin/cryptsetup luksFormat --batch-mode --key-file "$KEYDIR/ephemeral.key" --cipher aes-cbc-essiv:sha256 --hash ripemd160 --key-size 256 "/dev/{{ ephemeral_dev }}"
# make the encrypted volume available
/sbin/cryptsetup luksOpen --key-file "$KEYDIR/ephemeral.key" "/dev/{{ ephemeral_dev }}" ephemeral
# kill the key, live dangerously:
/usr/bin/shred -u "$KEYDIR/ephemeral.key"

/sbin/mkfs.ext3 $MAPPED_DEV

mount $MAPPED_DEV /mnt