slingring

#!/bin/bash

SEU_NAME=$1
if [ "$SEU_NAME" = "" ]; then
	echo "Usage: slingring UNIVERSE [COMMAND]"
	exit 1
fi

SCHROOT_NAME=${SEU_NAME}
SESSION_NAME=${SEU_NAME}-seu-session
COMMAND_ARGUMENT=$2
if [ "$COMMAND_ARGUMENT" = "" ]; then
	COMMAND_ARGUMENT="/bin/bash -l"
fi

check_session_exists()
{
	SESSION_ID=session:$1
	SESSION_MATCH=$(schroot --all-sessions -l|grep ^${SESSION_ID}$)

	if [ "$SESSION_MATCH" = "$SESSION_ID" ] ; then
		return 0
	else
		return 1
	fi
}

check_processes_stopped()
{
	schroot-process-check -q "$1"

	RESULT=$?
	if [ "$RESULT" = "0" ] ; then
		return 0
	elif [ "$RESULT" = "3" ] ; then
		return 1
	else
		echo "The schroot session could not be checked for running processes."
		echo "This could leave your universe in an inconsistent state."
		echo 
		echo "Please run schroot-process-check "$1" manually to find out more about the error."
		exit 1
	fi
}

check_session_running()
{
	RUNNING_SCHROOT_MOUNT=$(ps aux|grep "\ schroot -r -c $1\ ")

	if [ "$RUNNING_SCHROOT_MOUNT" = "" ] ; then
		return 1
	else
		return 0
	fi
}

check_session_valid()
{
	ROOT_MOUNT_MATCH=$(mount|grep "$1"\ )
	PROC_MOUNT_MATCH=$(mount|grep "$1"\/proc)
	SYS_MOUNT_MATCH=$(mount|grep "$1"\/sys)
	DEV_MOUNT_MATCH=$(mount|grep "$1"\/dev)
	DEVPTS_MOUNT_MATCH=$(mount|grep "$1"\/dev\/pts)
	X11_MOUNT_MATCH=$(mount|grep "$1"\/tmp\/.X11-unix)

	if [ "$ROOT_MOUNT_MATCH" = "" ] ||
		[ "$PROC_MOUNT_MATCH" = "" ] ||
		[ "$SYS_MOUNT_MATCH" = "" ] || 
		[ "$DEV_MOUNT_MATCH" = "" ] || 
		[ "$DEVPTS_MOUNT_MATCH" = "" ] ||
		[ "$X11_MOUNT_MATCH" = "" ] ; then
			return 1
	else
			return 0
	fi
}

if ! check_session_exists "$SESSION_NAME"; then
	echo Session does not exist. Creating...

	# get X11 authority into the chroot
	COOKIE_NAME=$(xauth list ${DISPLAY}|head -1 |sed "s/[\:\ ]*MIT-MAGIC-COOKIE-[\ a-f0-9]*/${DISPLAY}/")
	if ! [ -z "${COOKIE_NAME}" ]; then
        CHROOT_DIR=$(LANG="C" schroot -i -c ${SCHROOT_NAME}|grep Directory|sed s/[\ ]Directory[\ ]//)
        xauth extract ${CHROOT_DIR}${HOME}/.Xauthority ${COOKIE_NAME}
    fi

	# create session
	schroot -b -c "$SCHROOT_NAME" -n "$SESSION_NAME" > /dev/null
fi

while ! check_session_valid "$SESSION_NAME"; do
	if ! check_processes_stopped "$SESSION_NAME"; then
		echo "The universe seems to be in an invalid state, but there are still processes"\
		"running inside it. Please make sure that all services are stopped and all"\
		"portals are closed."
		echo
		read -p "Press any key to retry or CTRL+C to abort."
	else
		schroot --recover-session -c "$SESSION_NAME"
		if ! check_session_valid "$SESSION_NAME"; then
		    echo "The universe seems to be in an invalid state. That usually means that there"\
		    "is a schroot session but some expected mounts are missing. Unfortunately,"\
		    "slingring could not automatically recover the session."
            echo
            read -p "Press any key to retry or CTRL+C to abort."
	    fi
	fi
done

EXPORT_STRING=""
if ! [ -z ${DISPLAY} ] ; then
	EXPORT_STRING="$EXPORT_STRING export DISPLAY=\"$DISPLAY\";"
fi

if ! [ -z ${SSH_AUTH_SOCK} ] ; then
	EXPORT_STRING="$EXPORT_STRING export SSH_AUTH_SOCK=\"$SSH_AUTH_SOCK\";"
fi

if ! [ -z ${DBUS_SESSION_BUS_ADDRESS} ] ; then
	EXPORT_STRING="$EXPORT_STRING export DBUS_SESSION_BUS_ADDRESS=\"$DBUS_SESSION_BUS_ADDRESS\";"
fi

schroot -r -c "$SESSION_NAME" --directory="$HOME" -- /bin/bash -c "$EXPORT_STRING $COMMAND_ARGUMENT"

if check_session_running "$SESSION_NAME"; then
	exit 0
fi
if ! check_processes_stopped "$SESSION_NAME"; then
    echo
	echo "INFO: You closed the last portal to this universe but there are still processes"\
	"running inside it."
	echo "Please make sure to stop them before shutting down your computer to avoid umount locks."
	exit 0
fi
schroot -e -c "$SESSION_NAME"