prepare_vm_disks.sh

#!/bin/bash

# The MIT License (MIT)
#
# Copyright (c) 2015 Microsoft Azure
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# Original script:
#
# Script Name: vm-disk-utils.sh
# Author: Trent Swanson - Full Scale 180 Inc github:(trentmswanson)
# https://github.com/Azure/azure-quickstart-templates/blob/master/shared_scripts/ubuntu/vm-disk-utils-0.1.sh


# Base path for data disk mount points
DATA_BASE="/datadisks"
# Mount options for data disk
MOUNT_OPTIONS="noatime,nodiratime,nodev,noexec,nosuid,nofail"

# log() was missing, added a basic one
log()
{
    echo "$1"
}

is_partitioned() {
    OUTPUT=$(partx -s ${1} 2>&1)
    egrep "partition table does not contains usable partitions|failed to read partition table" <<< "${OUTPUT}" >/dev/null 2>&1
    if [ ${?} -eq 0 ]; then
        return 1
    else
        return 0
    fi    
}

has_filesystem() {
    DEVICE=${1}
    OUTPUT=$(file -L -s ${DEVICE})
    grep filesystem <<< "${OUTPUT}" > /dev/null 2>&1
    return ${?}
}

scan_for_new_disks() {
    # Looks for unpartitioned disks
    declare -a RET
    DEVS=($(ls -1 /dev/sd*|egrep -v "[0-9]$"))
    for DEV in "${DEVS[@]}";
    do
        # The disk will be considered a candidate for partitioning
        # and formatting if it does not have a sd?1 entry or
        # if it does have an sd?1 entry and does not contain a filesystem
        is_partitioned "${DEV}"
        if [ ${?} -eq 0 ];
        then
            has_filesystem "${DEV}1"
            if [ ${?} -ne 0 ];
            then
                RET+=" ${DEV}"
            fi
        else
            RET+=" ${DEV}"
        fi
    done
    echo "${RET}"
}

get_next_mountpoint() {
    DIRS=$(ls -1d ${DATA_BASE}/disk* 2>/dev/null| sort --version-sort)
    MAX=$(echo "${DIRS}"|tail -n 1 | tr -d "[a-zA-Z/]")
    if [ -z "${MAX}" ];
    then
        echo "${DATA_BASE}/disk1"
        return
    fi
    IDX=1
    while [ "${IDX}" -lt "${MAX}" ];
    do
        NEXT_DIR="${DATA_BASE}/disk${IDX}"
        if [ ! -d "${NEXT_DIR}" ];
        then
            echo "${NEXT_DIR}"
            return
        fi
        IDX=$(( ${IDX} + 1 ))
    done
    IDX=$(( ${MAX} + 1))
    echo "${DATA_BASE}/disk${IDX}"
}

add_to_fstab() {
    UUID=${1}
    MOUNTPOINT=${2}
    grep "${UUID}" /etc/fstab >/dev/null 2>&1
    if [ ${?} -eq 0 ];
    then
        echo "Not adding ${UUID} to fstab again (it's already there!)"
    else
        LINE="UUID=\"${UUID}\"\t${MOUNTPOINT}\text4\t${MOUNT_OPTIONS}\t1 2"
        echo -e "${LINE}" >> /etc/fstab
    fi
}

do_partition() {
# This function creates one (1) primary partition on the
# disk, using all available space
    _disk=${1}
    _type=${2}
    if [ -z "${_type}" ]; then
        # default to Linux partition type (ie, ext3/ext4/xfs)
        _type=83
    fi
    (echo n; echo p; echo 1; echo ; echo ; echo ${_type}; echo w) | fdisk "${_disk}"

#
# Use the bash-specific $PIPESTATUS to ensure we get the correct exit code
# from fdisk and not from echo
if [ ${PIPESTATUS[1]} -ne 0 ];
then
    echo "An error occurred partitioning ${_disk}" >&2
    echo "I cannot continue" >&2
    exit 2
fi
}
#end do_partition

scan_partition_format()
{
    log "Begin scanning and formatting data disks"

    DISKS=($(scan_for_new_disks))

	if [ "${#DISKS}" -eq 0 ];
	then
	    log "No unpartitioned disks without filesystems detected"
	    return
	fi
	echo "Disks are ${DISKS[@]}"
	for DISK in "${DISKS[@]}";
	do
	    echo "Working on ${DISK}"
	    is_partitioned ${DISK}
	    if [ ${?} -ne 0 ];
	    then
	        echo "${DISK} is not partitioned, partitioning"
	        do_partition ${DISK}
	    fi
	    PARTITION=$(fdisk -l ${DISK}|grep -A 1 Device|tail -n 1|awk '{print $1}')
	    has_filesystem ${PARTITION}
	    if [ ${?} -ne 0 ];
	    then
	        echo "Creating filesystem on ${PARTITION}."
	        mkfs -j -t ext4 ${PARTITION}
	    fi
	    MOUNTPOINT=$(get_next_mountpoint)
	    echo "Next mount point appears to be ${MOUNTPOINT}"
	    [ -d "${MOUNTPOINT}" ] || mkdir -p "${MOUNTPOINT}"
	    read UUID FS_TYPE < <(blkid -u filesystem ${PARTITION}|awk -F "[= ]" '{print $3" "$5}'|tr -d "\"")
	    add_to_fstab "${UUID}" "${MOUNTPOINT}"
	    echo "Mounting disk ${PARTITION} on ${MOUNTPOINT}"
	    mount "${MOUNTPOINT}"
	done
}


# Create Partitions
DISKS=$(scan_for_new_disks)
scan_partition_format