EBSmount: Automatically mount EC2/OpenStack EBS devices

EBSmount has 2 commands:

ebsmount-udev       Triggered by udev on EBS attach and detach
ebsmount-manual     Manually mount EBS device (simulates udev add trigger)

Features:

- Supports Amazon EC2 and OpenStack EBS devices
- Automatically mounts EBS devices when they are attached (via udev)
- Supports formatted devices, as well as partitions
- Ignores unformatted devices and unsupported filesystems
- Device/partition uniquely identifiable mountpoints
- Configurable mount options
- Hooking scripts execution upon mount (optionally)
- Convenience command for a one step format and mount
- Logging

Quick start:

- If the EBS device is not formatted, it will not be mounted
  automatically. For convenience, the user can format and mount the
  device in one step, for example:

    ebsmount-manual --format=ext4 /dev/sdf

Default configuration (/etc/ebsmount.conf):

ENABLED=True
RUNHOOKS=False
MOUNTDIR=/media/ebs
MOUNTOPTIONS=noatime
FILESYSTEMS=ext2 ext3 ext4
LOGFILE=/var/log/ebsmount.log

DEVPATHS=/devices/xen/vbd- /devices/virtio-pci/virtio

Unique mountpoints:

- Every EBS filesystem is mounted to its own uniquely identifiable
  mountpoint, based on:

    $(MOUNTDIR)/$(FS_UUID)[:6]

- For example:

    /media/ebs/a1b2c3

Hooking scripts:

- Once a filesystem is mounted, EBSmount will execute scripts in
  alpha-numeric ordering located in MOUNTPOINT/.ebsmount

- Hooking scripts execution is disabled by default. To enable execution,
  RUNHOOKS must be set to True in /etc/ebsmount.conf Additionally, hook
  scripts will only be executed if they are owned by root.

- The mountpoint of the device will be set in the environment for
  convenience, as MOUNTPOINT

- This provides a very powerful mechanism. In its simplest form, the
  user might want to symlink the mountpoint to a more accessible
  path, for example:

    MOUNTPOINT/.ebsmount/10symlink

    #!/bin/bash -e
    target=/vol
    mountp=$MOUNTPOINT
    [ -e $target ] || ln -s $mountp $target