xslab

#!/bin/bash
#===================================================================================
# This script implements some sort of lab management for XenServer virtualized
# machines. Virtual machines can be added and removed to or from the lab. 
#
# The lab machines can be reverted using several baselines (=snapshots), either
# manually using xslab or with adding a cronjob to automatically revert stopped
# vms.
# 
# Run the script without arguments to get a list of possible options.
#
# @Author:  Matthias Fetzer ( xslab [at] rofl.cat )
# @Version: 1.0
#
# @Changelog:
#             2015-09-15: Initial version                              ( fetzerms )
#
#
#===================================================================================

# Tags and prefixes. Feel free to adjust. 
# But make sure to use unique names.
tagEnabled="xslab:enabled"
tagDisabled="xslab:disabled"
baselinePrefix="xslab:baseline"

# Header/Footer/Text for the console output.
xslabHeader="+----[ xslab ]------------------------------------------------->"
xslabFooter="+-------------------------------------------------------------->"
xslabText="| "

#= listVMs =========================================================================
#
# Function:    listVMs
# Description: Lists all VMs.
#
# Examples:    listVMs lab_Debian8
#
#===================================================================================
listVMs(){

	printText "The following VMs are enabled:"
        printEmptyLine
	listEnabledVMs
        printEmptyLine
	printText "The following VMs are disabled:"
        printEmptyLine
	listDisabledVMs
}

#= listEnabledVMs ==================================================================
#
# Function:    listEnabledVMs
# Description: Lists all enabled VMs.
#
# Examples:    listEnabledVMs lab_Debian8
#
#===================================================================================
listEnabledVMs(){
	OIFS=$IFS
	IFS=","
	for vm in $(xe vm-list tags:contains=$tagEnabled params=name-label --minimal); do
		printText "  - $vm"
	done
	IFS=$OIFS
}

#= listDisabledVMs =================================================================
#
# Function:    listDisabledVMs
# Description: Lists all disabled VMs.
#
# Examples:    listDisabledVMs lab_Debian8
#
#===================================================================================
listDisabledVMs(){
	OIFS=$IFS
	IFS=","
	for vm in $(xe vm-list tags:contains=$tagDisabled params=name-label --minimal); do
		printText "  - $vm"
	done
	IFS=$OIFS
}

#= enableVM ========================================================================
#
# Function:    enableVM
# Description: Enables a given VM
#
# Parameter:   $1 - The vm to enable
#
# Examples:    enableVM lab_Debian8
#
#===================================================================================
enableVM(){
        vm=$1

        if isVMDisabled $vm; then
        	uuid=$( getVmUUID $vm )
        	setEnabled $uuid
        	unsetDisabled $uuid
                printText "$vm has been enabled."
        else
                printText "$vm is not disabled or not added to xslab."
        fi
}

#= disableVM =======================================================================
#
# Function:    disableVM
# Description: Disables a given VM
#
# Parameter:   $1 - The vm to disable
#
# Examples:    disableVM lab_Debian8
#
#===================================================================================
disableVM(){
        vm=$1

        if isVMEnabled $vm;  then
        	uuid=$( getVmUUID $vm )
        	setDisabled $uuid
        	unsetEnabled $uuid
                printText "$vm has been disabled."
        else
                printText "$vm is not enabled or not added to xslab."
        fi
}

#= addVM ===========================================================================
#
# Function:    addVM
# Description: Adds a given vm to xslab and creates an initial baseline.
#
# Parameter:   $1 - The vm to add
#
# Examples:    addVM lab_Debian8
#
#===================================================================================
addVM(){
	vm=$1
        if isVMEnabled $vm || isVMDisabled $vm ; then
                printText "$vm is already added to xslab."
        else
                printText "Adding $vm to xslab."
        	uuid=$( getVmUUID $vm )
        	setEnabled $uuid
        	unsetDisabled $uuid 2> /dev/null
        	baselineCreate $vm
        fi
}

#= delVM ===========================================================================
#
# Function:    delVM
# Description: Removes a given vm from xslab
#
# Parameter:   $1 - The vm to remove
#
# Examples:    delVM lab_Debian8
#
#===================================================================================
delVM(){
	vm=$1
        if isVMEnabled $vm || isVMDisabled $vm ; then
        	uuid=$( getVmUUID $vm )
        	unsetEnabled $uuid 2> /dev/null
        	unsetDisabled $uuid 2> /dev/null
                printText "Removing $vm from xslab."
        else
                printText "$vm is not added to xslab."
        fi
}

#= setEnabled ======================================================================
#
# Function:    setEnabled
# Description: Removes the disabled tag from a given VM.
#
# Parameter:   $1 - The vm to set the enabled tag for.
#
# Examples:    setEnabled lab_Debian8
#
#===================================================================================
setEnabled(){
	uuid=$1
	xe vm-param-add param-name=tags param-key="$tagEnabled" uuid=$uuid
}

#= unsetEnabled ====================================================================
#
# Function:    unsetEnabled
# Description: Removes the disabled tag from a given VM.
#
# Parameter:   $1 - The vm to unset the enabled tag for.
#
# Examples:    unsetEnabled lab_Debian8
#
#===================================================================================
unsetEnabled(){
	uuid=$1
	xe vm-param-remove param-name=tags uuid=$uuid param-key="$tagEnabled"
}

#= setDisabled =====================================================================
#
# Function:    setDisabled
# Description: Removes the disabled tag from a given VM.
#
# Parameter:   $1 - The vm to set the disabled tag for.
#
# Examples:    setDisabled lab_Debian8
#
#===================================================================================
setDisabled(){
	uuid=$1
	xe vm-param-add param-name=tags param-key="$tagDisabled" uuid=$uuid
}

#= unsetDisabled ===================================================================
#
# Function:    unsetDisabled
# Description: Removes the disabled tag from a given VM.
#
# Parameter:   $1 - The vm to unset the disabled tag for.
#
# Examples:    unsetDisabled lab_Debian8
#
#===================================================================================
unsetDisabled(){
	uuid=$1
	xe vm-param-remove param-name=tags uuid=$uuid param-key="$tagDisabled"
}

#= getVmUUID =======================================================================
#
# Function:    getVmUUID
# Description: Retrieves the XenServer uuid for a given VM name.
#
# Parameter:   $1 - The VM to retrieve the uuid for.
#
# Returns:     The vms UUID
#
# Examples:    getVmUUID lab_Debian8
#
#===================================================================================
getVmUUID(){
	vm=$1
	uuid=$(xe vm-list name-label=$vm params=uuid --minimal)
	echo $uuid
}

#= baselineCreate ==================================================================
#
# Function:    baselineCreate
# Description: Creates a new baseline for a given VM
#
# Parameter:   $1 - The VM to create a new baseline for
#
# Examples:    baselineCreate lab_Debian8
#
#===================================================================================
baselineCreate(){
	vm=$1
	uuid=$( getVmUUID $vm )
	snapshotLabel="$baselinePrefix"_"$vm_$( date +%s )"
	descriptionLabel="$baselinePrefix"_"$vm"

        printText "Creating new baseline for $vm:"
        printEmptyLine

        printText "  - Creating new snapshot for $vm ... "
	xe vm-snapshot vm=$vm new-name-label=$snapshotLabel new-name-description=$descriptionLabel > /dev/null

        printEmptyLine
        printText "New baseline for $vm created."
}

#= getBaselineUUID =================================================================
#
# Function:    getBaselineUUID
# Description: Returns the XenServer Snapshot-UUID for a given Baseline
#
# Parameter:   $1 - The baseline to retrieve the uuid for.
#
# Returns:     The baselines UUID
#
# Examples:    getBaselineUUID baseline_lab_Debian8
#
#===================================================================================
getBaselineUUID(){
	snapshotName=$1
	baselineUUID=$( xe snapshot-list name-label=$snapshotName params=uuid --minimal )
	echo $baselineUUID
}

#= revertVM ========================================================================
#
# Function:    revertVM
# Description: Reverts a given and enabled VM to its latest baseline.
#
# Parameter:   $1 - The vm to revert
#
# Examples:    revertVM lab_Debian8
#
#===================================================================================
revertVM(){
	vm=$1

        if ! isVMEnabled $vm ; then
                printText "$vm is disabled or not added to xslab."
        fi


	snapshot=$( xe snapshot-list name-description="$baselinePrefix"_"$vm" params=name-label --minimal | sed 's/,/\n/g' | sort -nr | head -1 )
        printText "Reverting $vm to baseline $snapshot"

	BaselineUUID=$( getBaselineUUID $snapshot )
	xe snapshot-revert snapshot-uuid=$BaselineUUID
        xe vm-cd-eject vm=$vm > /dev/null 2>&1
	xe vm-start vm=$vm
}

#= autoRevert ======================================================================
#
# Function:    autoRevert
# Description: Reverts all enabled and stopped VMs to the latest baseline.
#
# Examples:    autoRevert
#
#===================================================================================
autoRevert(){
        printText "Reverting all enabled and powered off VMs:"
        printEmptyLine
	uuids=$(xe vm-list tags:contains=$tagEnabled params=uuid --minimal power-state=halted)
	IFS=","
	for uuid in $uuids; do
		vmName=$(xe vm-list uuid=$uuid params=name-label --minimal)
		revertVM $vmName
	done
}

#= isVMRunning =====================================================================
#
# Function:    isVMRunning
# Description: Checks if a given VM is running
#
# Parameter:   $1 - The vm to check
#
# Returns:     1 - if the vm is not running
#              0 - if the vm is running
#
# Examples:    isVMRunning lab_Debian8
#
#===================================================================================
isVMRunning(){
	vm=$1
	uuid=$( getVmUUID $vm )
	powerState=$(xe vm-list uuid=$uuid params=power-state --minimal)
	if [ "$powerState" == "running" ]; then
		return 0
	else
		return 1
	fi
}

#= isVMEnabled =====================================================================
#
# Function:    isVMEnabled
# Description: Checks if a given VM is enabled.
#
# Parameter:   $1 - The vm to check
#
# Returns:     1 - if the vm is not enabled
#              0 - if the vm is enabled
#
# Examples:    isVMEnabled lab_Debian8
#
#===================================================================================
isVMEnabled(){
        vm=$1
        uuid=$(xe vm-list name-label="$vm" tags:contains="$tagEnabled" --minimal)
        if [ -z $uuid ]; then
                return 1
        else
                return 0
        fi
}

#= isVMDisabled ====================================================================
#
# Function:    isVMDisabled
# Description: Checks if a given VM is disabled.
#
# Parameter:   $1 - The vm to check
#
# Returns:     1 - if the vm is not disabled
#              0 - if the vm is disabled
#
# Examples:    isVMDisabled lab_Debian8
#
#===================================================================================
isVMDisabled(){
        vm=$1
        uuid=$(xe vm-list name-label="$vm" tags:contains="$tagDisabled" --minimal)
        if [ -z $uuid ]; then
                return 1
        else
                return 0
        fi
}

#= baselineList ====================================================================
#
# Function:    baselineList
# Description: Lists all baselines for a given VM.
#
# Parameter:   $1 - The vm to list baselines for.
#
# Examples:    baselineList lab_Debian8
#
#===================================================================================
baselineList(){
        vm=$1
        baselines=$( xe snapshot-list name-description="$baselinePrefix"_"$vm" params=name-label --minimal | sed 's/,/\n/g' | sort -nr )

        printText "Listing baselines for $vm:"
        printEmptyLine

        typeset -i i=1
        for baseline in $baselines ; do

                unixDate=$( echo $baseline | awk -F "_" '{ print $NF }' )
                readableDate=$(date -d @"$unixDate" "+%Y-%m-%d / %H:%M")
                printText "   ( $(printf "%3s" "$i") ) @ $readableDate - $baseline"
                let i++
        done
}

#= baselineDelete ==================================================================
#
# Function:    baselineDelete
# Description: Deletes a given baseline for a vm.
#
# Parameter:   $1 - The vm to delete the baseline from.
#              $2 - The number of the baseline to delete.
#
# Examples:    baselineDelete lab_Debian8 2
#
#===================================================================================
baselineDelete(){
        vm=$1
        num=$2
        baselines=$( xe snapshot-list name-description="$baselinePrefix"_"$vm" params=name-label --minimal | sed 's/,/\n/g' | sort -nr )

        typeset -i i=1
        for baseline in $baselines ; do
                if [ $i -eq $num ]; then
                        printText "Deleting baseline $baseline from $vm:"
                        uuid=$( getBaselineUUID $baseline)
                        xe snapshot-destroy snapshot-uuid=$uuid
                fi
                let i++
        done
}

#= printHelp =======================================================================
#
# Function:    printHelp
# Description: Prints the help
#
# Examples:    printHelp
#
#===================================================================================
printHelp(){

        printText "Usage: $(basename $0) <command> <parameters>"
        printText 
        printText "   Commands:"
        printText "     - add               : Add a vm to xslab. This will create an initial baseline."
        printText "     - delete            : Delete a vm from xslab. This will NOT delete baselines."
        printText "     - enable            : Enable a VM which has been added to xslab."
        printText "     - disable           : Disable a VM which has been added to xslab."
        printText "     - list              : List VMs that have been added to xslab."
        printText "     - revert            : Revert VM to latest baseline."
        printText "     - auto-revert       : Revert all enabled and powered off VMs to the latest baseline and boot them."
        printText "     - baseline-create   : Create a new baseline for a given VM."
        printText "     - baseline-delete   : Delete the n-th baseline from a given VM."
        printText "     - baseline-list     : Lists all baselines for a given VM."
        printText
        printText "   Parameters:"
        printText "     - --vm/-m       : The VM name to perform operations on."
        printText "     - --num/-n      : The n-th element to perform operations on. "
        printText "                       Currently only used with baseline-delete"
        printText
        printText "   Examples:"
        printText "     - $(basename $0) list"
        printText "     - $(basename $0) add --vm lab_debian8"
        printText "     - $(basename $0) baseline-create --vm lab_debian8"
        printText "     - $(basename $0) baseline-delete --vm lab_debian8 --num 1"
        printText "     - $(basename $0) baseline-list --vm lab_debian8"
        printText "     - $(basename $0) revert --vm lab_debian8"
        printText "     - $(basename $0) auto-revert"       
        printText "     - $(basename $0) delete --vm lab_debian8"
        printText 
}


# helper to print xslab header
printHeader(){
        echo -e "$xslabHeader"
}

# helper to print xslab footer
printFooter(){
	echo -e "$xslabFooter"
}

# helper to print text between header and footer.
printText(){
        while IFS= read -r line; do
                echo "$xslabText$line"
        done <<< "$@"
}

# helper to print an empty line.
printEmptyLine(){
        printText
}

command=$1
shift

OIFS=$IFS
IFS=$'\n'

# Argument parsing
while [[ $# > 1 ]]; do

	key="$1"

	case $key in
		-m|--vm)
			vm="$2"
			shift
			;;
                -n|--num)
                        num="$2"
                        shift
                        ;;
		*)
			shift # ignore unknown option.
		;;
	esac
done	
shift

printHeader
printEmptyLine

case $command in
	add )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else
        		addVM $vm
                fi
		;;
	delete )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else
        		delVM $vm
                fi
		;;
	enable )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else
        		enableVM $vm
                fi
		;;
	disable )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else
        		disableVM $vm
                fi
		;;
	list )
		listVMs
		;;

	baseline-create )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else
        		baselineCreate $vm
                fi
		;;

	baseline-delete )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                elif [ -z $num ]; then
                        printText " --num argument is required."
                else
	        	baselineDelete $vm $num
                fi
		;;

	baseline-list )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else
                        baselineList $vm
                fi
		
		;;

	revert )
                if [ -z $vm ]; then
                        printText " --vm argument is required."
                else 
        		revertVM $vm
                fi
		;;

	auto-revert )
		autoRevert
		;;
	* )
		# print the help
		printHelp
		;;
esac

printEmptyLine
printFooter