#!/bin/sh
#
# This script will try to upgrade an LXC Debian template
#   1. Start the LXC container if available
#   2. Run some script to upgrade the container
#   3. Stop the container

# This script can be call by a cronjob (eg. daily, weekly,…)

# Vars {{{
readonly PROGNAME=$(basename "${0}")
readonly PROGDIR=$(readlink -m $(dirname "${0}"))
readonly ARGS="${*}"
readonly NBARGS="${#}"
[ -z "${DEBUG}" ] && DEBUG=1
## Export DEBUG for sub-script
export DEBUG

readonly CT_ID_DEFAULT="199121"
readonly SLEEP_DELAY_DEFAULT="5"

## Colors
readonly PURPLE='\033[1;35m'
readonly RED='\033[0;31m'
readonly RESET='\033[0m'
readonly COLOR_DEBUG="${PURPLE}"
# }}}
usage() {                                                       # {{{

	cat <<- EOF
usage: $PROGNAME [-d|-h|-i|-s]

Start and upgrade an LXC container for Debian template

EXAMPLES :
    - Upgrade default LXC container (${CT_ID_DEFAULT}) :
        ${PROGNAME}

    - Specify the container ID :
        ${PROGNAME} --id 666

OPTIONS :
    -d,--debug
        Enable debug messages.

    -h,--help
        Print this help message.

    -i,--id
        Choose a different LXC container ID (default ${CT_ID_DEFAULT}).

    -s,--sleep
        Set a different delay to test container between each
        different state (default: ${SLEEP_DELAY_DEFAULT}).

	EOF

}
# }}}
debug_message() {                                               # {{{

	local_message="${1}"

	## Print message if DEBUG is enable (=0)
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6b\e[m\n' "DEBUG − ${PROGNAME} : ${local_message}"

	return 0
}
# }}}
error_message() {                                               # {{{

	local_error_message="${1}"
	local_error_code="${2}"

	## Print message if DEBUG is enable (=0)
	[ "${DEBUG}" -eq "0" ] && printf '%b\n' "ERROR − ${PROGNAME} : ${RED}${local_error_message}${RESET}"

	exit "${local_error_code:=66}"
}
# }}}
define_vars() {                                                 # {{{

	## If ct_id wasn't defined (argument) {{{
	if [ -z "${ct_id}" ]; then
		## Use default value
		readonly ct_id="${CT_ID_DEFAULT}"
	fi
	## }}}

	## If sleep_delay wasn't defined (argument) {{{
	if [ -z "${sleep_delay}" ]; then
		## Use default value
		readonly sleep_delay="${SLEEP_DELAY_DEFAULT}"
	fi
	## }}}

}
# }}}
is_proxmox_absent() {                                           # {{{

	## By default, Proxmox is absent on an host
	return_is_proxmox_absent="0"

	## Check if the system runs on a PVE kernel
	if ! uname --kernel-release -- | grep --quiet -- "pve";
	then
		return_is_proxmox_absent="0"
		debug_message "is_proxmox_absent − \
Proxmox is ${RED}absent${COLOR_DEBUG} on this host."
	else
		return_is_proxmox_absent="1"
		debug_message "is_proxmox_absent − \
Proxmox seems ${RED}present${COLOR_DEBUG} on this host."
	fi

	return "${return_is_proxmox_absent}"

}
# }}}
is_lxc_container_absent() {                                     # {{{

	local_ct_id="${1}"

	## By default, the LXC container is absent from the current host
	return_is_lxc_container_absent="0"

	## Check if the system runs on a PVE kernel
	if ! /usr/sbin/pct list -- | grep --quiet "${local_ct_id}";
	then
		return_is_lxc_container_absent="0"
		debug_message "is_lxc_container_absent − \
The LXC container (${RED}${local_ct_id}${COLOR_DEBUG}) is ${RED}absent${COLOR_DEBUG} from this host."
	else
		return_is_lxc_container_absent="1"
		debug_message "is_lxc_container_absent − \
The LXC container (${RED}${local_ct_id}${COLOR_DEBUG}) is ${RED}present${COLOR_DEBUG} on this host."
	fi

	return "${return_is_lxc_container_absent}"

}
# }}}
is_lxc_container_state() {                                      # {{{

	local_ct_id="${1}"
	local_ct_state="${2}"

	## Compare the status of the LXC container with argument
	if /usr/sbin/pct status "${local_ct_id}" -- | grep --quiet --word-regexp "${local_ct_state}";
	then
		return_is_lxc_container_state="0"
		debug_message "is_lxc_container_state − \
The LXC container (${RED}${local_ct_id}${COLOR_DEBUG}) is in ${RED}${local_ct_state}${COLOR_DEBUG} state."
	else
		return_is_lxc_container_state="1"
		debug_message "is_lxc_container_state − \
The LXC container (${RED}${local_ct_id}${COLOR_DEBUG}) is not in ${RED}${local_ct_state}${COLOR_DEBUG} state."
	fi

	return "${return_is_lxc_container_state}"

}
# }}}
start_lxc_container() {                                         # {{{

	local_ct_id="${1}"

	## By default, the container is not running
	return_start_lxc_container="1"

	## Start LXC container state
	/usr/sbin/pct start "${local_ct_id}" || exit 1

	## Wait a little for the container to start
	sleep "${sleep_delay}"

	## Verify LXC container status
	if is_lxc_container_state "${local_ct_id}" "running";
	then
		return_start_lxc_container="0"
		debug_message "start_lxc_container − \
LXC container ${RED}${local_ct_id}${COLOR_DEBUG} is now ${RED}running${COLOR_DEBUG}."
	else
		return_start_lxc_container="1"
		debug_message "start_lxc_container − \
LXC container ${RED}${local_ct_id}${COLOR_DEBUG} is still ${RED}stopped${COLOR_DEBUG}."
	fi

	return "${return_start_lxc_container}"

}
# }}}
stop_lxc_container() {                                          # {{{

	local_ct_id="${1}"

	## By default, the container is running
	return_stop_lxc_container="1"

	## Stop LXC container state
	/usr/sbin/pct stop "${local_ct_id}" || exit 1

	## Wait a little for the container to stop
	sleep "${sleep_delay}"

	## Verify LXC container status
	if is_lxc_container_state "${local_ct_id}" "stopped";
	then
		return_stop_lxc_container="0"
		debug_message "stop_lxc_container − \
LXC container ${RED}${local_ct_id}${COLOR_DEBUG} is now ${RED}stopped${COLOR_DEBUG}."
	else
		return_stop_lxc_container="1"
		debug_message "stop_lxc_container − \
LXC container ${RED}${local_ct_id}${COLOR_DEBUG} is still ${RED}running${COLOR_DEBUG}."
	fi

	return "${return_stop_lxc_container}"

}
# }}}
upgrade_container() {                                           # {{{

	local_ct_id="${1}"

	## Keep output if DEBUG mode is activated
	if [ "${DEBUG}" -eq "0" ]; then
		/usr/sbin/pct exec "${local_ct_id:-/dev/null}" -- bash -c "wget https://git.ipr.univ-rennes1.fr/cellinfo/scripts/raw/master/proxmox/proxmox.template.debian.sh --output-document=/tmp/proxmox.template.debian.sh" || exit 2
		/usr/sbin/pct exec "${local_ct_id:-/dev/null}" -- bash -c "chmod +x /tmp/proxmox.template.debian.sh" || exit 2
		/usr/sbin/pct exec "${local_ct_id:-/dev/null}" -- bash -c "/tmp/proxmox.template.debian.sh" || exit 2
	else
		/usr/sbin/pct exec "${local_ct_id:-/dev/null}" -- bash -c "wget --quiet https://git.ipr.univ-rennes1.fr/cellinfo/scripts/raw/master/proxmox/proxmox.template.debian.sh --output-document=/tmp/proxmox.template.debian.sh" || exit 2
		/usr/sbin/pct exec "${local_ct_id:-/dev/null}" -- bash -c "chmod +x /tmp/proxmox.template.debian.sh" || exit 2
		/usr/sbin/pct exec "${local_ct_id:-/dev/null}" -- bash -c "/tmp/proxmox.template.debian.sh" > /dev/null 2>&1 || exit 2
	fi

}
# }}}

main() {                                                        # {{{

	## If Proxmox is not yet available on this host {{{
	### Exit
	is_proxmox_absent \
		&& exit 0
	## }}}

	## Define all vars
	define_vars

	## If the LXC container ID is absent from this host {{{
	### Exit
	is_lxc_container_absent "${ct_id}" \
		&& exit 0
	## }}}

	## If the LXC container ID is already running {{{
	### Exit with error message
	is_lxc_container_state "${ct_id}" "running" \
		&& error_message "LXC container (${ct_id}) is already running. \
Please power it off if you don't have any work in progress." "3"
	## }}}

	## If the LXC container ID is stopped {{{
	### Try to start the container
	is_lxc_container_state "${ct_id}" "stopped" \
		&& start_lxc_container "${ct_id}"
	## }}}

	## Try to upgrade the container {{{
	### And re-stop the container
	### Then exit with success the script
	upgrade_container "${ct_id}"        \
		&& stop_lxc_container "${ct_id}"  \
		&& exit 0
	## }}}

}
# }}}

# Manage arguments                                                # {{{
# This code can't be in a function due to argument management

if [ ! "${NBARGS}" -eq "0" ]; then

	manage_arg="0"

	## If the first argument is not an option
	if ! printf -- '%s' "${1}" | grep -q -E -- "^-+";
	then
		## Print help message and exit
		printf '%b\n' "${RED}Invalid option: ${1}${RESET}"
		printf '%b\n' "---"
		usage

		exit 1
	fi

	# Parse all options (start with a "-") one by one
	while printf -- '%s' "${1}" | grep -q -E -- "^-+"; do

	case "${1}" in
		-d|--debug )                          ## debug
			DEBUG=0
			;;
		-h|--help )                           ## help
			usage
			## Exit after help informations
			exit 0
			;;
		-i|--id )                             ## Use given CT ID
			## Move to the next argument
			shift
			## Define ct_id
			readonly ct_id="${1}"
			;;
		-s|--sleep )                          ## Use given sleeping delay
			## Move to the next argument
			shift
			## Define sleep_delay
			readonly sleep_delay="${1}"
			;;
		* )                                   ## unknow option
			printf '%b\n' "${RED}Invalid option: ${1}${RESET}"
			printf '%b\n' "---"
			usage
			exit 1
			;;
	esac

	debug_message "Arguments management − \
${RED}${1}${COLOR_DEBUG} option managed."

	## Move to the next argument
	shift
	manage_arg=$((manage_arg+1))

	done

	debug_message "Arguments management − \
${RED}${manage_arg}${COLOR_DEBUG} argument(s) successfully managed."
else
	debug_message "Arguments management − \
No arguments/options to manage."
fi

# }}}

main

exit 255