slcreatevm.sh

#!/bin/bash
##
## /usr/local/script/slcreatevm.sh
## Create a kernel-based VM
##
## Created on 14 OKT 2013
## Version 1.0 dated 20 OKT 2013
##

# Set variables and default values
set -u
F_TEST=FALSE		# Script test flag
F_OVERWRITE=FALSE	# Overwrite previosu VM flag
VMINSTALLSCRIPT=""	# KVM installer
ARGUMENTFILE=""		# File with arguments for KVM installer
ISOFILE=""			# ISO-file
CMD_CREATEVM=""		# Command to execute and create VM
CMD_ARGVALSEP=" "	# Seprator between arguments and value on command line
EXITCODE=0			# Assume everything went ok
argument[0]=""		# Array with arguments
value[0]=""			# Array with argument values

# Define functions
function checktocontinue() {
	# Ask to continue
	read -p "Continue (y/n)? " -n 1 -r
	if [[ "$REPLY" =~ ^[Yy]$ ]]; then
		printf "\n"
	else
		printf "\nYou choose not to continue. Exiting.\n"
		exit 1
	fi
}

# Check if this script is run as root, otherwise exit.
if [[ $(whoami) != root ]]; then
	printf "Must be root to execute this script. Exiting.\n"
	exit 1
fi

# Evaluate given options using getops; set variables accordingly
while getopts "i:oth" opt; do
   case "$opt" in
     i)
       ISOFILE=${OPTARG}
       #printf -- "ISO-file specified: %s\n" "${ISOFILE}"
       ;;
     o)
       F_OVERWRITE=TRUE
       #printf -- "Previous VM will be overwritten."
       ;;
     t)
       F_TEST=TRUE
       printf -- "Test mode: script will only dry-run.\n"
       ;;
     \? | h)
       printf -- "Script for creating KVM guests to be run by the system libvirtd instance.\n"
       printf -- "Usage: %s [-h] [-t] [-o] [-i isofile] \n" "${0##*/}"
       printf -- "   -h   Help: show this help message and exit.\n"
       printf -- "   -t   Test mode: script will only dry-run.\n"
       printf -- "   -i   ISO-file: install KVM-guest from 'isofile' using virt-install.\n"
       printf -- "        If no ISO-file is specified, vmbuilder will be used to install a JeOS KVM-guest.\n"
       printf -- "   -o   Overwrite VM if already existing (vmbuilder only; virt-install should prompt).\n"
       printf -- "Required files in the current installation directory: \n"
       printf -- "   '<vmbuilder|virt-install>.arguments': file with arguments passed to the install command.\n"
       # printf -- "   'firstboot.sh': optional script to be run on first boot of the virtual machine.\n"
       # printf -- "   'firstlogin.sh': optional script to be used on first user login.\n"
       exit 2
       ;;
     :)
       printf -- "Option -%s requires an argument. Exiting.\n" "${OPTARG}"
       exit 1
       ;;
   esac
done

# Check install method and set-up initial command
if [[ -z "${ISOFILE}" ]]
   then
	VMINSTALLSCRIPT="vmbuilder"
	CMD_ARGVALSEP=" "
	CMD_CREATEVM="${VMINSTALLSCRIPT} kvm ubuntu -v --libvirt qemu:///system "
	if [[ ${F_OVERWRITE} == TRUE ]]
	   then
		CMD_CREATEVM="${CMD_CREATEVM} -o "
	fi
        printf "No ISO-file specified. Using '%s' to install a JeOS KVM-guest.\n"  ${VMINSTALLSCRIPT}
   else
	VMINSTALLSCRIPT="virt-install"
	CMD_ARGVALSEP="="
	CMD_CREATEVM="${VMINSTALLSCRIPT} --connect=qemu:///system --cdrom=${ISOFILE} --check-cpu "
	printf "Using '%s' to install the OS from the specified ISO-file '%s'.\n"  ${VMINSTALLSCRIPT} ${ISOFILE}
fi
if [[ ! -x $(which "${VMINSTALLSCRIPT}") ]]
   then
        printf "\nCannot execute %s. Have the required packages correctly been installed? Exiting.\n" ${VMINSTALLSCRIPT}
        exit 1
fi

# Check current directory
printf "Executing %s in %s. " "${VMINSTALLSCRIPT}" "$(pwd)"
checktocontinue

# Read arguments from file in current VM directory
ARGUMENTFILE="${VMINSTALLSCRIPT}.arguments"
if [[ -r "${ARGUMENTFILE}" ]]
   then
	# Compile argument list from the first field of each record.
	i=0
	while read line; do
  	   if [[ "${line}" =~ ^[^#]*= ]]; then
    		argument[i]="--"${line%% =*}
    		value[i]=${line#*= }
    		((i++))
  	   fi
	done < ${ARGUMENTFILE}

	# Compile final command
	printf "The following %s arguments were specified in %s:\n" "${VMINSTALLSCRIPT}" "${ARGUMENTFILE}"
	j=0
	while [[ ${j} -lt ${i} ]]; do
	   printf "   %s %s \n" ${argument[$j]} ${value[$j]}
	   CMD_CREATEVM="${CMD_CREATEVM} ${argument[$j]}${CMD_ARGVALSEP}${value[$j]} "
	   ((j++))
	done

	printf "Please check if these arguments are correct. "
	checktocontinue
   else
        printf "Cannot read arguments from '%s'. Exiting.\n" "${ARGUMENTFILE}"
        exit 1
fi

printf "The following command will be executed: \n'%s'\n" "${CMD_CREATEVM}"
# Test or real?
if [[ ${F_TEST} == TRUE ]]
   then
	# Test run only
	case "${VMINSTALLSCRIPT}" in
	   vmbuilder)
		printf "Test mode specified, but vmbuilder cannot dry-run.\n"
		;;
	   virt-install)
		CMD_CREATEVM="${CMD_CREATEVM} --dry-run"
		printf "Test mode specified, so virt-install will dry-run only. "
		checktocontinue
		${CMD_CREATEVM}
		EXITCODE=$?
		;;
	   *)
		printf "Error in script. Unknown install command %s.\nThis should not occur. Exiting." "${VMINSTALLSCRIPT}"
		exit -1
		;;
	esac
   else
	# The real thing
	printf "YOU ARE ABOUT TO CREATE A NEW KVM-GUEST. "
	checktocontinue
	${CMD_CREATEVM}
	EXITCODE=$?
fi

# End of script; exit with exit-code of the real install script
printf "All done.\n"
exit ${EXITCODE}